15 Most Common Guppy Diseases (With Pictures): Prevention and Treatment

Guppy Diseases

Dealing with guppy diseases is never a fun activity for any fish owner. However, there are plenty of treatments for guppies, as well as some preventions that can help your guppies stay healthy and live active and productive lives.

The one rule of thumb that everyone will always tell you is that “It is much harder to prevent diseases in healthy ones than it is to cure a sick fish.”

If you are looking for common guppy diseases, causes, and treatments, you are in the right place.

Guppy Diseases Prevention

There are a lot of ways to prevent diseases in guppies. Most of these follow good common sense, but it helps to know what to do to keep your fish healthy [1].

You should always quarantine new fish before adding them to your community tank. This is to make sure that they don’t have any diseases that could potentially infect your other fish.

You should also keep your tank clean by doing regular water changes and vacuuming the gravel to remove any waste buildup. A dirty tank is a breeding ground for bacteria and parasites that can make your fish sick.

Also, inspect your tank on a daily basis to make sure that everything looks normal. This way you can catch any problems early on and treat them before they become serious.

All of these measures will help you keep your tank thriving and your fish as healthy as can be!

reduce stress

Reduce Stress

While most people probably think of “stress” as a human disease, it can actually have a great impact on guppies as well.

Stress weakens [2] all parts of a guppy’s health and can make it much more susceptible to the various diseases that you will see listed below.

One great way to lower stress in any guppy’s system is to provide them with plenty of places to hide and “explore.” You’ll want to include plenty of live plants in your aquarium along with other things like tree roots or leaves so that guppies have an environment that feels natural to them.

If you are keeping an aquarium that has more aggressive fish than guppies with them, it may be a problem for the group of guppies specifically.

You’ll also want to take all of the preventive tank measures listed above. A tank with fluctuating water temperatures is a big factor that can cause guppies to get sick, leading you down a much more difficult road when caring for your fish.

Dealing with guppy diseases is never a fun activity for any fish owner. However, there are plenty of treatments for guppies as well as some prevention measure that can help your fish stay healthy and live active and productive lives.

The one rule of thumb that everyone will always tell you is that “It is much harder to cure a sick fish than it is to prevent diseases in healthy ones”.

If you’re looking for common guppy diseases, causes, and treatment; you are in the right place.

Common Guppy Diseases, Symptoms & Treatment

Common guppy fish diseases and illnesses can be categorized as parasitic, bacterial, fungal, or viral. As you may know, parasites and bacteria are present in every aquarium but remain harmless unless the fish’s immune system is weakened. Fungus, on the other hand, typically comes from previous health conditions. Viral infections are less common than others.


Most parasitic ailments result from bad water conditions, stress environment, or new fish that were not properly quarantined before being introduced to the main tank.

The most frustrating thing about parasites is that they are the most contagious and hard to kill.

There is a wide range of parasites that can affect guppies. The most common ones include the following:

Ich (White Spot)

White Spots guppy

This is one of the classic diseases that almost everyone who raises fish is pretty well aware of.

Ich (pronounced ICK), or “white spot disease,” is caused by an obligate pathogen scientifically known as Ichthyophthirius multifiliis. Due to its complex life cycle [3], Ich is one of the most contagious fish diseases and can quickly spread through an entire aquarium population if left untreated.

So if you think one of your guppies might be infected, you must treat the entire tank, not just the individual fish.

  • Multiple white spots on your guppy fish’s body or fins
  • Numerous guppies just died suddenly in one aquarium
  • Guppies use objects in the aquarium to scratch against
  • Flashing and scale loss
  • Clamped fins
  • Lethargic

Diagnosis of Ich can be tricky since many of these clinical signs can present with other non-serious issues, so you may want a veterinary examination from your local fish store or aquarium club before you treat.

  1. Start to up the water temperature gradually – your goal should be approximately 82° F (the high end of their comfort zone) for two weeks to speed up the life cycle of the Ich parasite.
  2. Use an aquarium-safe medication product following their guidelines for use. 
  3. Perform 10-20% partial water changes daily.
  4. Continue treating for at least 10-14 days.
  5. Monitor the temperature and observe your fish closely. Discontinue treatment if your fish appear to be in distress

Author notes: Slowly increase the temperature by about 1 degree per day to prevent thermal shock, and make sure the new water you are adding is the same temperature as what you just removed.

Velvet (Rust or Gold Dust disease) in Guppies

Velvet (Rust or Gold Dust disease) in Guppies

Velvet, also known as rust or gold dust disease, is caused by a dinoflagellate parasite called Piscinoodinium pillulare. A fatal parasitic infection can quickly kill your guppy fish if effective treatments are not used immediately and consistently.

  • Your guppy fish has a fuzzy film on the skin (resembles gold or rust dust)
  • You may see your guppies scratching
  • Guppies may become lethargic
  • Labored breathing and loss of weight
  • Clamped fins
  • Sudden death

Like Ich, velvet is pretty hard to identify. Other things can cause these remarkably similar clinical signs, which will require a microscope to correctly identify by your aquatic veterinarian.

  • Increase the water temperature by just a few degrees
  • Turning off the lighting will also help (Piscinoodinium need light to photosynthesize [4])
  • Performing a salt dip is the safest and most effective method of treatment.
  • Copper sulfate can also be used, but this medication can change the alkalinity and pH. Moreover, it can kill invertebrates [5]. You need to follow the instructions carefully.

Anchor Worms (Lernaea spp.)

Anchor Worms in Goldfish

The anchor worms (Lernaea spp.) are not real worms but copepod parasites that appear as thread-like structures attached to the skin or fins of your fish, where they feed on the host’s tissue fluids and blood.

These parasites are most often found in pond fish like koi and goldfish but can also affect aquarium fish, including guppies.

  • The visible protuberance of whitish-green threads on scales
  • The affected fish may scratch against objects
  • You may notice the inflammation and redness around the “worm”

While this parasite is macroscopic, you should not try to manually remove the anchor worm from your guppies because this could damage their skin.

Instead, take your fish to the veterinarian for treatment or treatment with a salt bath for about 5 minutes daily until the parasite falls off.

Body and Gill flukes

Flukes in guppy fish are a group of microscopic, parasitic trematodes (or flatworms) that invade a fish’s gills or skin. The two types of flukes are the gill flukes (Dactylogyrus spp.) and the body flukes (Gyrodactylus spp.)

They are characteristic monogenean parasites, which means they have the haptor or holdfast used to attach them to the fish’s skin cells and mucus, weakening the fish and allowing other parasites or bacteria to invade.


Flukes produce similar symptoms to ich. Unlike the visible ich spots on the fish, flukes are not always visible and can be difficult to see with the naked eye, except if you have a black fish, or they can be observed during a movement with a magnifying glass.

Other symptoms of flukes in guppy fish include:

  • Loss of color
  • Gasping at the water’s surface
  • Excess mucus production covering gills or body
  • Clamped fins
  • Reddened skin & flared gills
  • Small blood dots on the skin and fins
  • Lethargic

First, you need to determine the genus of fluke to know what medication will be effective. The most common treatment for flukes is using a gamut of chemicals —salt, formalin, and Praziquante.

Check out Diana’s treatments and disease management strategies for skin flukes (Gyrodactylus species) on guppies here: Dianawalstad.com

Freshwater Fish Lice (Argulus spp.)

Freshwater Fish Lice (Argulus spp.)

Freshwater fish lice (Argulus spp) are parasitic crustaceans. Like anchor worms (Lernaea spp), Argulus spp can be found in ponds, aquariums, and the wild but most often in freshwater.

Older stages of Argulus species are macroscopic parasites with large, flattened shells adapted for rapid movement over the skin’s surface. With their hooks and needle-like mouthparts, they periodically attach themselves to the skin of their hosts, where they feed on body tissue.


The most obvious symptom is the presence of small (3–7 mm long x 2–4 mm wide [6]), dark oval, lice-like parasites attached to the skin, gill chamber, and mouth of your fish.

Beyond that, Lice symptoms can present in a variety of ways.

  • Infected guppies may rub themselves against objects in the tank in an effort to remove lice
  • Guppies are aggravated and restless

Common treatments include:

  • Physically removing the lice with a hemostat or forceps.
  • Treating with chemicals like iodine.
  • Using a salt bath (35ppt) for about 5 minutes daily until the parasites fall off.

Since adult female Argulus will lay eggs onto hard surfaces and live plants in aquariums, it’s important to kill any eggs with Diflubenzuron (Dimilin) [7].

Chilodonella (Chilodonella spp.)

Chilodonella species in fish are ciliate parasites that can move over the surface of the skin and gills of guppies. They are between 0.5–0.7 mm in size, heart-shaped, and have bands of cilia on their ventral sides.

Chilodonella can be hard to diagnose but are easy to treat if caught early, especially for young fish.

  • Labored breathing
  • Clamped fins
  • loss of appetite
  • Layer of mucus secretion covering objects in the aquarium. 

Chilodonella can survive in a wider range of different water temperatures than other parasites. Therefore, raising the water temperature does not work.

The most common treatments are chemicals like formaldehyde, acriflavine, and methylene blue. If you choose to treat with chemicals, be sure to remove carbon from your filter because it will absorb the treatment. 


Hexamita is often referred to as the main pathogen that causes “hole-in-the-head” (HITH) and head and lateral line erosion (HLLE) disease in fish. This is NOT true. Many factors contribute to HITH or HLLE syndrome [8], and Hexamita is only one of them.

Hexamita is a pyriform-shaped, flagellated protozoan. They are common in the intestine of cichlids such as severumsangelfish, discus, Oscars, and African cichlids but can cause fatal tissue and lead to severe systemic visceral disease in any freshwater fish.

  • White poop
  • Decreased appetite (Spitting food back out)
  • Bloated belly
  • White, stringy feces

Hexamita is usually treated with metronidazole in medicated fish food. The most common medications are Hikari Metro+™, SeaChem Laboratories MetroPlex, or API General Cure. If your guppy fish has stopped eating, you can try to add metronidazole directly to the water. 

Tetrahymena spp (Guppy Disease)

Tetrahymena species are actively motile ciliated protozoa, primarily inhabiting the surfaces of fish and seeking to consume any organic matter they find. However, they have pear-shaped bodies with longitudinal rows of cilia that allow them to invade their host’s muscles, coelom, and ocular fluids, causing disease.

Although it can affect other types of fish, it most often causes the death of large numbers of guppies (Poecilia reticulata).


The most common symptoms of Tetrahymena resemble ich (Ichthyophthirius multifiliis). But ich tends to cover the entire body of the guppy fish, while tetrahymena only affects a small section at a time. The difference can’t be confirmed without microscopic analysis.

Here are some other symptoms to look for:

  • White spots on their flanks and fins
  • Clamped fins
  • Loss of appetite
  • Labored breathing
  • Lethargy

Unfortunately, there is no reliable treatment for Tetrahymena infections in guppies. Scientists found a potential treatment [9] under laboratory conditions in 2010, but it has not been turned into a commercial product or available to aquarists.

Tetrahymena species are more resistant to salinity than ich (Ichthyophthirius multifiliis), so the salt bath treatment is not effective.

You can try using formalin or medications containing malachite green and copper’s active ingredient.

The common malachite green medications on the market include:

And the common copper-based medications include:


Bacteria is the second most common cause of diseases in guppies after parasites. Most bacterial infections are secondary to parasite infestations, physical injury, or long-term stress, including poor water quality, overcrowding, inappropriate tank mates, or cheap, inadequate food.

Many different types of bacteria can infect guppy fish and produce a similar syndrome. The most common ones are Aeromonas, Edwardsiella, Epitheliocystis, Flavobacterium, Pseudomonas, Mycobacterium, Streptococcus, and Vibrio.

Diagnosing the exact type of bacteria is nearly impossible unless you can access an incubator, making the treatment very tricky and often ineffective. Therefore, the most common treatments for bacterial infections in guppies are broad-spectrum antibiotics.

Guppy Dropsy

Guppy Dropsy

Dropsy is a fatal ailment that affects the kidneys of guppy fish, and there is no known cure. Since it’s more of a symptom than an actual disease, it could be caused by hundreds of factors.


In advanced stages, the fish’s scales will start to stick out from its body in a “pine cone” effect, hence the name “pinecone disease.”.

Other symptoms include:

  • Swollen belly and anus
  • Bulging eyes
  • High respiratory rate
  • Redness of the skin or fins
  • Reddish tints on skin and fins
  • Abnormal swimming behavior

Dropsy is not always treatable; it depends on the underlying cause. You can try treating it with an Epsom Salt bath in a quarantine aquarium or making medicated food with a broad-spectrum antibiotic when the guppy fish appears to have pinecone-like scales.

In most cases, the fish will not recover, and it’s kinder to euthanize them.

Popeye In Guppy Fish

Popeye In Guppy Fish

Like most bacterial infections, pop eyes (or bulging eyes) in guppy fish for so many different reasons that it can become a losing battle to try fighting for a fish with this symptom.

Typical causes of popeye include injuries to the eye, mycobacteria in the water, and viruses. In addition, a group of aerobic, gram-positive bacteria called Corynebacterium is the most common cause of bulging eyes in guppies.

Author notes: Most aquarium bacteria that infect fish are gram-negative.


The gram-positive Corynebacterium species should be treated with proper antibiotics. Some antibiotics are designed to treat gram-negative bacteria, while others work better against gram-positive bacteria.

A good antibiotic to start with is erythromycin – the main ingredient of Mardel Maracyn and Thomas Labs Fish Mycin. Make sure it’s Mardel Maracyn, not Maracyn 2, as the latter contains a different active ingredient Minocycline (works better against gram-negative bacteria.)

Fin & Rail Rot in Guppies

Fin & Rail Rot in Guppies

If you see a guppy that has rotting fins with white edges, it is due to a gram-negative bacterial infection, which causes the fins and tail to rot away as the fish’s immune system tries to fight the infection.

Sometimes, ragged fins could be caused by aggression from tank mates and fin nippers, especially when the white edges are absent.


Using the medicated feed with broad-spectrum antibiotics is an effective way of treating most gram-negative bacterial infections.

The common antibiotics on the market include:

Beware these antibiotics DON’T work when added directly to water; they only work when the fish ingests them.

Columnaris in Guppy Fish

Columnaris in Guppy Fish
Photo: naeburgerr

Probably most fish keepers have heard of Columnaris or cottonmouth infection. It’s one of the most common guppy fish infections that pose a serious threat to your aquariums.

Columnaris is caused by Flavobacterium columnare, an aerobic, rod-shaped, gram-negative bacterium. It is often mistaken for a fungal infection because of its furry white growth on the fish’s skin.

This disease is very contagious and can quickly spread throughout your aquarium, leading to mass fish die-offs. Columnaris often occur in new tanks or when there’s a sudden temperature or water quality change.

  • Gray or whitish growth on the head, fins, or gills
  • Progressive deterioration of the back
  • Cotton-wool lesions on the mouth
  • Rotting fins

Terramycin is the most commonly used antibiotic to treat Columnaris. You can dose Terramycin either in fish food or as a bath. In addition, you should add salt to the water to reduce osmotic shock from the infection.

Swim bladder in Guppy Fish

As you may know, the swim bladder is an internal organ that helps the fish to maintain its buoyancy. The swim bladder is a common syndrome in fancy goldfish and bettas. It’s less common in guppies.

The causes of swim bladder syndrome are usually multifactorial, meaning that several underlying causes often contribute to the disease’s development, making the treatment quite difficult.

Another factor that can lead to swim bladder problems is genetics. Well, there’s a certain amount of luck involved. That’s why you should always choose healthy-looking guppies from a reputable dealer.


If the swim bladder doesn’t work properly, you will see your fish:

  • Sink to the bottom or float to the top of the aquarium
  • Hang at an angle in the water
  • Swim erratically or upside down
  • Swollen belly and Curved back
  • Loss of appetite

Clamped Fins in Guppy Fish

Like popeye or swim bladder, the clamped fin is not a specific disease. It refers to a condition where the fish’s fins are held tightly against the body due to multiple problems, including stress, poor water quality, or parasitic infection. 

  • Their fins look like someone has ironed them down,
  • The fish is listless
  • Labored breathing
  • Lethargic

If you have the right water parameters, parasites like velvet, ich, and tetrahymena can also cause this problem. See supportive treatment above.


Virtually fungal infections originate from previous health conditions. True fungal diseases are seldom in live fish. Besides the causes of poor water quality and the buildup of decomposing material, bacterial infections and physical injuries to the skin can expose the fish to secondary fungal infection.


  • Initially, you’ll see small white or grey growth on the fish skin, mouth, or fins
  • Untreated fungus usually has cotton-like growths
  • Excess mucus production
  • Eventually, the fungus will kill the fish


Catching fungal infection early is crucial. If your fish is still alive and showing early signs of a fungal infection, you can treat the fish with a topical anti-fungal medication in a quarantine aquarium, such as API fungus cure and Mardel Maracyn.

Removing filter carbon and turning off your UV sterilization while treating the fish. 


The last group of guppy diseases I want to touch on is viruses. They are tiny organisms that can only replicate inside the cells of all aquarium fish.

Also, viral infections can be difficult to diagnose, and there is no effective treatment. So, the best way to protect your fish is to prevent them from getting infected in the first place.

Red Spots or Blotches on Guppies

More pics

Like goldfish, red spots or blotches on the fins or skin of guppies can happen when the fish are infected with a deadly virus called Viral hemorrhagic septicemia. Ammonia poisoning also can evoke skin damage, but it’s not often seen in a well-maintained aquarium.

VHSV or VHSv (short for Viral hemorrhagic septicemia virus) is an acute, contagious [10], and often fatal virus that creates red, bloody spots or blotches on a fish’s skin, gills, eyes, and body.

  • Red blotches or sports on skin, gills, eyes, and bodies
  • Popeye
  • Swollen (fluid-filled) abdomens
  • Their color may fade
  • Abnormal swimming behavior

VHSV should be attempted to treat with broad-spectrum antibiotics in their food. Same as other gram-negative bacterial infections.

Don’t Freak Out!

Now you have it. These are the most common guppy fish diseases and how to treat them.

As with any freshwater fish, early detection and treatment are key to a successful outcome. So, keep a close eye on your guppies, and don’t hesitate to seek professional help if you can’t identify the problem or treat it effectively.

Being a responsible fishkeeper also means taking proactive steps to prevent disease outbreaks. So, ensure you follow the basic rules of aquarium husbandry, such as regular water changes, a quality filter, and quarantining new fish or decorations before adding them to your tank.

I hope you found this article helpful. If you have any questions or comments, please feel free to leave them below. Thanks for reading!

Article Sources:

  1. Prevention and Therapy of Fish Diseases [FAO]
  2. The Concept of Stress in Fish [ScienceDirect]
  4. Sustainable aquaculture requires environmental-friendly treatment strategies for fish diseases [Wiley Online Library]
  5. Therapeutic Considerations in Aquaculture [MerckVetmanual]
  6. ARGULUS (FISH LOUSE) INFECTIONS IN FISH [University of Florida]
  7. Parasitic Diseases of Fish [MerckVetmanual]
  8. Hole in the Head [AquariumScience]
  9. Treatment development for systemic Tetrahymena sp. infection in guppies, Poecilia reticulata Peters [ResearchGate]
  10. Viral Hemorrhagic Septicemia [Lowa State University]

Male Vs. Female Molly Fish (What’s the Difference?)

female Molly Fish

Molly fish are a popular choice for aquariums, thanks to their bright colors and low-maintenance care requirements. They’re also peaceful and easygoing, which makes them a good option for beginners.

However, they often exhibit aggression if you keep only males and the number of females in the aquarium is too low. Indeed, in the latter case, these male mollies will harass females by using nipping and chasing behaviors, and this behavior gets worse when they are ready to mate.

Since mollies are schooling fish, it’s important to get a group of at least six fish with the proper male-to-female ratio – the general rule of thumb is three females for every male. This will help reduce aggression and ensure that everyone gets along.

Moreover, discovering which are male and female is important if your intent is breeding.

In this post, you’ll learn some basic information that will help you determine the gender of molly fish. We also cover the obvious signs of pregnant molly fish.

Let’s get started.

Female Molly Fish Facts

Female Molly Fish

For people who are new to keeping fish and considering choosing Molly fish as the first fish, here are some interesting facts about them. While if already learned these facts and you’re standing in the fish store thinking about purchasing some female molly fish, feel free to scroll down to the section on sexing Mollies.

Species Profile

Mollies are a member of a family of aquarium fish known as “live bearers.” The most common and widespread livebearers in the aquarium trade belong to the Poeciliidae family, including guppies, platies, Endler’s livebearer, mosquito fish, and swordtails.

Poecilia is one of the tribes of Poeciliidae. Nearly all species in Poecilia are called mollies, but two species: the popular guppy fish (P. reticulata) and the Endler’s livebearer (P. wingei), are excluded owing to their distinct body shapes.

As with all livebearers, female molly fish retain their eggs until they are fully formed, giving birth to live fry. This process is known as “ovoviviparous,” and it’s different from the more common method of reproduction in fish, which is “oviparity.”

Origin and Distribution

Mollies (Poecilia sp.) can be found from Southern America down into Central America, where they inhabit slow-moving fresh, brackish, and salt waters.

Due to the extremely variable coloration, mollies have been selectively bred in captivity for many years. As a result, many different color morphs and fin shapes are now available all over the world, including albino, black, dalmatian, lace, marble, gold dust, and lyretail.

Colors and Markings

Virtually most popular ‘fancy’ molly varieties are hybrids. As we mentioned, mollie species have been selectively bred for centuries. Here are many beautiful and common hybrid mollies in the trade.

  • Solid Black mollies – Completely black— body, fins, eyes.
  • Dalmatian mollies – Colored like a Dalmatian dog
  • Lyretail mollies – have a lyre-shaped caudal fin
  • Balloon Mollies – have a round and bulbous shape
  • Sailfin Mollies – develop a taller dorsal fin
  • Amazon Mollies – is for all practical purposes female


In nature, mollies primarily feed on algae and other plant-based food, so you must offer lots of spirulina and blanched vegetables like zucchini, lettuce, and spinach. They will also accept several aquatic invertebrates as snacks, such as frozen worms, daphnia, and brine shrimp.

Author note: Mollies are not considered one of the best algae eaters among aquarists; they just like to snack on it.


The size of molly fish really depends on the specific species and environmental conditions. There are more than 40 described species currently included in the genus Poecilia. Some of the smaller species, like the Shortfin Molly (P. mexicana), grow to only about 3.2″ (8 cm), while the largest, Giant sailfin molly (P. velifera), can reach up to 7 inches (18 cm).


The typical lifespan of a molly fish is 3-5 years varying in species. The quality of care you provide will have a significant impact on how long your molly fish will live.

Tank Setup & Care

Despite the Mollies being hardy and highly adaptable, they are perhaps the most difficult livebearer to keep in a home aquarium. These delicate fish are susceptible to developing an ailment known as “shimmies” due to the poor water quality and stressful environment.

Shimmying in mollies and other livebearers, like boating in bettas, is not an aquarium disease but a compounding symptom caused by water conditions and stress.

Therefore, it is important to provide your mollies with a spacious aquarium with plenty of hiding places and good filtration, and regular water changes.

Here is a care sheet for the mollies. Depending on the species you get, you may need to make adjustments.

Male Vs. Female Molly Fish

Now, we have learned the basics about Molly fish, and let’s move on to the next step, which is learning how to distinguish between male and female mollies.

No matter what type of Molly fish you have — shortfin, sailfin, dalmatian, black, or Lyretail, juvenile mollies look pretty much the same. There is no effective way to tell the genders apart.

However, it’s fairly easy to tell the difference between mature male and female mollies.

Anal Fin

The easiest way to tell is by looking at their anal fin. Male mollies develop a modified long, thin “anal fin” instead of a normal anal fin, called a gonopodium, which is used to inseminate the female while mating. The female mollies have a round, broad, and fan-shaped anal fin. Additionally, females sometimes have a noticeable “gravid” spot, a dark area near the base of their anal fin that contains eggs during pregnancy.

Body Shape

Another way to tell the difference between male and female mollies is by looking at their body shape. Mature females usually look larger than males and have a more rounded belly, while males tend to be slimmer with a flatter belly. 

Color Intensity

You can also determine the gender of molly fish by looking at the intensity of their colors. Male mollies tend to be more colorful than females, with brighter and more intense patterns and colors. This is especially true of these solid color varieties, like gold and black mollies.

On the other hand, the males take on elaborate colors on their elongated, flowing dorsal fins, which is not often seen on females.

Pregnant Female Molly Fish

Pregnant Female Molly Fish

There are several ways to identify a pregnant female molly fish. Some signs are more obvious than others, but you can usually tell if your female molly is pregnant by looking for the following symptoms:

A Swollen Belly

The most obvious sign of a pregnant female molly is a swollen belly. This is caused by the developing eggs inside the female’s body. Depending on how far along she is in her pregnancy, her belly may be only slightly swollen or extremely bloated.

Dark Gravid Spot

As the pregnancy progresses, you may also notice a dark gravid spot near the base of her anal fin. This is where the eggs are contained and will be released when she gives birth.

Behavioral Changes

Pregnant females may also exhibit some behavioral changes, such as being more aggressive or territorial, as well as becoming more reclusive and hiding more often.

Eat More

They will also eat more food than usual as their body is working hard to produce the eggs. Therefore, you may need to increase the amount of food accordingly. 

Seek Warmth

Since the fry (baby fish) develop better in warm water, pregnant mollies will often seek out the warmest waters in the aquarium, such as the heater or surface of the water. They prefer to stay there during their pregnancy.


Do Mollies Change Gender?

Mollies do not change gender. However, if a male molly is stressed, he may become less colorful and take on the appearance of dull or gray.

Are female molly fish aggressive?

Female mollies are not naturally aggressive but may become more aggressive when pregnant as they become more territorial.

Where to buy female molly fish?

You can buy female molly fish from your local pet store or online retailers. Females are generally inexpensive.


Distinct differences exist between male and female mollies, most notably in their anal fins and body shape. Additionally, males tend to be more colorful than females, while females may have a gravid spot near the base of their anal fin when pregnant. 

If mollies appeal to you, remember that they are social fish that do best in groups. It’s a good idea to have at least six individuals with at least three females for every male. This will help keep the females from harassing the males too much.

If you have any lingering questions about sexing molly fish, feel free to ask in the comments below!

Guppy Fin Rot 101: Everything You Need to Know (Causes & Treatment)

Guppy Fin Rot

Guppy fin rot is a common and treatable disease that affects a variety of fish, not just guppies! If you spot and treat it early enough, your fish can fully recover and return to a happy state, but if you don’t know your fish has it or you leave it untreated, it can be deadly.

Keep reading this guide to learn all about guppy fin rot, how to treat it, and how to prevent it from returning in the future.

What is Guppy Fin Rot, and What Are the Causes?

Guppy fin rot is a disease that can affect a number of aquarium fish species, but it’s most common among fish like Betta‘s that have long flowing tails. It can be both a fungal or bacterial infection that is caused by poor water quality or a stressful environment for your fish.

What Are The Symptoms Of Guppy Fin Rot?

Fortunately, fin rot in guppies is pretty easy to spot, especially if you’re checking for symptoms regularly. However, it’s important to be able to spot all the different symptoms so you can figure out how serious the fin rot is, as well as whether it’s bacterial or fungal.

There are three levels of severity when it comes to fin rot: Mild, Major, and Severe. Each level has its own set of symptoms, but in general, it’s relatively easy to spot fin rot in your fish if you’re taking the time to inspect them. As a fish owner, knowing the symptoms is essential, so you can identify the severity and whether it’s bacterial or fungal.

Depending on which type of fin rot your fish is plagued with, they may need a different treatment.

Bacterial vs Fungal Guppy Fin Rot

Bacterial fin rot causes the fins to look ragged and uneven. Fungal fin rot causes the fins to develop a white edge along the edge of the fins, and the fins appear more even, as opposed to bacterial infections. If you notice white spots, it could be ich instead of fin rot. Sometimes, both types of infection are seen together.

Mild Guppy Tail Rot Symptoms and Treatment

Mild Guppy Tail Rot

If you catch mild Guppy fin rot early, then there’s a good chance your fish can make a full recovery. The symptoms of this level of infection are usually very minor and may only include some redness or inflammation around the edge of the fins.

Symptoms of Mild Fin Rot in Guppy Fish

  • Signs of irritation
  • The fins look sore and red
  • The tips of the fins may change color to be darker, brown, white, or grey
  • It is localized to the tips of the fins
  • The edges of the fins may begin to look tattered, but it won’t be severe at a mild stage

How To Treat Mild Fin Rot In Guppies:

When fin rot is in the mild stages, it’s much easier to treat than major or severe. Here’s how you should go about treating mild guppy fish fin rot.

  • Firstly, cleaning the gravel at the bottom of the tank is vital. Removing any waste or debris will immediately help the situation because they feed bacteria that is causing the fin rot to occur.
  • Once the tank’s bottom is cleaned out, do a 25% water change, replacing the old water with fresh and clean water.
  • Check your water parameters to ensure they’re all where they should be. Check the pH balance, chlorine, nitrite, temperature, nitrate, and ammonia levels. You can easily pick up a testing kit from your local pet store or purchase one online.
  • Once you’ve ensured the environment is clean and ideal, you can begin to treat your fish. When it comes to minor fin rot, an API Stress Coat or aquarium conditioner typically does the trick.
  • Follow the label and manufacturer-specified instructions until the guppy fish fin rot starts to clear up.
  • It’s crucial that you remove the carbon filter in the quarantine tank, as it can have a negative impact on the treatment’s effectiveness.
  • Keep a close watch on your fish to ensure they’re improving and returning to their optimal health.

Major Fin Rot Symptoms and Treatment In Guppies

Major Fin Rot In Guppies

You’ve been looking after your guppies for a long time and you know that they are worth the effort, but if their fin rot is getting out of control then don’t waste another second. This condition can be fatal and open up the possibility to many illnesses or diseases.

Symptoms of Major Fin Rot in Guppy Fish

  • Fins are now discolored, likely darkened
  • Significant parts of the fin may be rotted away
  • Fins are starting to die completely
  • If it’s a fungal infection, the fins will have white fuzz along the edges
  • Chunks of the fin may be falling off in the tank

How To Treat Major Fin Rot In Guppies:

If you’ve missed the initial symptoms of mild fin rot, your fish will likely become more ill, and the severity will increase to major fin rot. Once this has occurred, your treatment plan will be a bit different. Major fin rot will need to be cared for as soon as possible to prevent further infection.

  • Upon recognizing that your guppy fish has fin rot, you will need to set up a separate quarantine tank for them. Acclimatize them by using water from the old tank.
  • Once you have the aquarium fish settled in the main tank, you will need to perform a complete water change and clean all the surfaces that you can. This will help prevent the fin rot from returning and prevent tank mates from getting infected as well.
  • Mix water and aquarium salt and let it dissolve. Once it’s completely dissolved, you can add it to the quarantine tank. Please follow the manufactures instructions for the amount you should use.
  • While using aquarium salt, you will be required to change the water altogether each day. Ensure you don’t put more than the recommended amount in more than once in the water.
  • The aquarium salt will tell you the recommended amount of time to do this for, which is typically around a week.

Severe Fin Rot Symptoms and Treatment In Guppies 

If fin rot is left untreated for a couple of weeks, it can develop into severe fin rot or body rot. Severe fin rot is considered extreme, and it’s difficult to save your fish at this time due to the progression of the infection.

Symptoms of Severe Fin Rot in Guppy Fish

  • Fins are entirely eaten away and decayed
  • The body of your fish has started to rot
  • If it’s a fungal infection, there may be white fuzz along the area where the fins previously were
  • Your fish is lethargic
  • Loss of appetite

How To Treat Severe Fin Rot In Guppies:

Once your fish has reached the severe fin rot stage, it’s likely they won’t survive the infection. Treatment is much more intense to try and save your fish once they get body rot. If it’s fungal, you will require a strong medication, like API Pimafix, and if it’s bacterial infection, you’ll need API Furan 2.

  • Firstly, you will need to set up a quarantine tank for your fish, but you will require an air bubbler this time. Some of the medications to treat severe fin rot also impede the tank’s oxygen levels, so an air bubbler will help keep the water oxygenated.
  • Once your fish is settled in the new tank, you can begin providing medication, depending on which type of infection they have.
  • Ensure you are performing 100% water changes before providing more medication, as they can become poisoned.
  • Clean out your other tank thoroughly and replace the water 100% with fresh water.
  • Inspect your other fish to ensure the infection has not impacted them.
  • Once your fish is showing improvements, and the medication cycle is done, you can reintroduce them into your original tank.

As the severity of the fin rot increases, the treatment for your fish becomes more extreme. Each level of severity has its own set of treatments, and depending on whether it’s bacterial or fungal will make a difference as well. If you notice something is wrong in the early stages, treatment is easier and more effective.

If you’re dealing with major or severe fin rot, your fish will have a more challenging time making a full recovery. When you notice issues with your fish, it’s always recommended to seek the advice of a trusted professional who can help you get your fish back to optimal health.

When you begin to treat fin rot, you will want to create a quarantine tank for your infected fish. This helps prevent the spread of fin rot to their tank mates but allows the treatment to be effective for your one fish and not all of them.

As mentioned, fin rot can also be caused by stress, so if the fish has been bullied, putting them in a separate tank prevents fin nipping.

To learn more about how to care for guppies then check out this article.

How to Prevent Fin Rot In Guppies?

Prevention is critical when it comes to common guppy diseases and infections, and thankfully preventing fin rot is reasonably straightforward. Here are ways to prevent fin rot.

Regular Tank Cleanings

Cleaning your tank regularly prevents a whole host of problems that can affect your fish. Depending on the size of your tank and how many fish you have, you will need to find out a cleaning schedule that works for you. The bigger the tank and the more fish means that you need to clean the tank more often.

Don’t Overfill Your Tank

Overcrowding is one of the most important ways to prevent fin rot. It increases the risk of infection because of the increased bioload from all the different fish. It also causes unnecessary stress on your fish when you continue to introduce new tank mates without increasing the size of your tank. The more fish you have, the more likely some will become aggressive, which can cause fin nipping.

Change Water Regularly

Much like cleaning your tank often, you’ll want to ensure you’re performing water changes. The size will impact how often you need to do this. Tanks that are smaller may require water changes every three or four days, while larger tanks may require changing every other week.

guppy fish filter

Use a Quality Filter

Filters are critical when trying to keep your tank clean, as it is constantly filtering out excess debris, ammonia, and waste, which can all cause sickness in fish. Many fish owners try to get away without having a filter when they own guppies, but it’s always recommended to have a quality filter in any fish tank, regardless of size or fish types.

Provide a High Quality Food

Feeding your fish should include a high-quality diet and the best food you can. Providing them with adequate nutrition is critical, helping boost their immune system, so they can fight off any potential infections that may be introduced to the fish tank. Most fish need a combination of plant matter and meat, and you can give them live food treats every so often.

(Not sure what is the high quality food for guppies? Check out our top picks)

If you Have any Bullies, Remove Them

When fish start to become aggressive, they can become relentless. Any bullies need to be removed as soon as you notice that it’s happening. The more bullying that takes place means the risk for sickness dramatically increases.

If you don’t have a separate tank for a fish that is aggressive, you can try to return them to the pet shop that you got them. If these are not ideal for you, you can provide your fish with some extra hiding spots and try to manage as best you can.

How Contagious is Fin Rot to Tank Mates?

Thankfully, fin rot is not very contagious, but that shouldn’t stop you from acting quickly to prevent fin rot from spreading. Especially if your infected fish moves beyond mild fish rot, it can end up affecting your entire tank.

Suppose you discover one of your fish has developed fin rot. In that case, you must deep clean your tank and perform a 100% water change to ensure that it does not spread, and do not reintroduce your infected fish until they are entirely better.

By keeping a close eye on your fish and visually inspecting them often, you can feel confident that you’ll catch any fin rot before it becomes a massive problem.

You May Also Like: Guppy Fish 101: Types, Care, Lifespan, Breeding And Tank Mates


Guppy fin rot can happen to the best of fish owners, but it’s essential to treat it as soon as you can to give your fish the best fighting chance. Now that you’re prepared with the knowledge of what it looks like, the symptoms, how to prevent it and how to treat fin rot, you can effectively keep your fish happy and healthy.

The best thing you can do for your fish is keeping their environment clean and healthy, ensuring you’re not overstocking your tank, and visually inspecting them often.

Do Guppies Eat Algae? (Here’s the Answer)

Do Guppies Eat Algae

If you are a fish enthusiast, there’s a high chance that you have guppies in the aquarium.

This tropical species, also known as rainbow fish because of its vibrant colors, is one of the most loved freshwater aquarium fishes worldwide. Also, have you ever noticed how the algae growing on the hose fitting of your aquarium magically disappears sometimes? 

Well, you should thank your guppies for that! But is that a good thing? That’s why we are here with our informative guide in case you’re wondering – “do guppies eat algae?”

Keep reading to find out more. 

Do Guppies Eat Algae?

Yes, guppies feed on algae when it becomes too prevalent in their surroundings. The latter is a source of high protein and fibre, so guppies do like to feed on it. 

The growth of algae in your fish tank is not a pretty sight to see, so it is an upside that guppies are omnivores and eat it. That helps out with the cleaning to an extent.

Is Algae Good For Guppies?

Growth Of Algae

You must have observed that algae typically grows around the filter intake or airline tubing in your fish tank. This is because it is autotrophic in nature and needs oxygen to thrive. 

For those of you who don’t know, autotrophs are organisms that can prepare their own food through photosynthesis in the presence of oxygen and sunlight.

Algae’s Effect On Guppies

Guppies have the tendency to keep munching, which implies no matter how many bloodworms or brine shrimps you feed them, they’ll still feed on the algae growing in the aquarium. 

However, eating algae does not have any negative impact on these fishies, so you don’t have anything to stress about. The only thing is, algae need a rich supply of oxygen for growth and deplete its content in the water. 

As a result, your guppies will have to compete with these autotrophs for air to breathe. This is not healthy, leading to a decline in the nutrients essential for their development. 

Therefore, you need to watch out for the notorious growth of algae and clean it as soon as possible.

Can Guppies Live On Algae?

Yes, guppies can survive on algae, but not for long. The weeds serve as an aid in their nutrition but cannot replace fish food completely. Additionally, algal growth is thick and can block out the light when present in excess, preventing it from penetrating the tank. 

This can obscure plant growth and ultimately affect your fishes’ health. Meaning, you should not allow algae to prevail in the water for long. 

What Type Of Algae Do Guppies Eat?

These omnivorous fishes can eat mainly four types of algae that are commonly found in the aquarium water. Let’s get to know them in detail, so you have a sure and sorted idea of what goes inside your fishes’ tummies at all times.

Hair Algae

Hair algae is a very common green alga that normally carpets over plants and other surfaces. Falling under the Oedogonium genus, this species develops coats of densely packed filamentous structures. 

It is likely to grow if the light is available in excess compared to the needs of the fis fiber plants in the tank. Speaking of growth, the type typically found in aquaria has long and soft filaments and grows when the system is developing its balance in the cycling phase. 

Furthermore, hair algae can very easily disappear by itself, without any need for external cleaning, provided sufficient aquatic animals that eat algae are present in the tank. 

Staghorn Algae

These red algae derive their name because of their structural resemblance with a stag’s horns. 

Staghorn algae are really ugly to look at and are grayish-green in color. Now, you must wonder why they are grouped under the red algae family (Rhodophyceae) if they aren’t red. No worries, we’ll clear that for you.

This species has phycoerythrin pigments in addition to chlorophyll and therefore assumes a red shade when dipped in alcohol. Moreover, it often grows on the leaf margins of water plants and is extremely difficult to remove manually.

Black Beard Algae

Black beard algae, also referred to as brush algae, is another red species belonging to the Rhodophyceae family that guppies love feeding on. Their tufts seem like brushes or beards, and that’s why they are named so.

They grow when there is a large fish stock in the water tank but no aquatic plant. What’s more, these algae stubbornly cling to the ground and thrive in low carbon dioxide conditions.

Blue-Green Algae

Last but not least, blue-green algae (BGA) are unique and quite different from other species of algae. That is because they do not have a true nucleus (nuclear envelope isn’t developed) and are called cyanobacteria, falling under the category of prokaryotic organisms.

Guppies are fond of these bacteria and munch on them if they are present in the tank.

Do Guppies Clean Algae?

Can You Use Guppies To Control Algae? The answer is yes but guppies can clean algae only up to a certain extent. 

Bristlenose plecos, Siamese, and Chinese algae eaters are a few competent species that can effectively feed on algae to clean the tank. They often peck at the weed growth since it contains certain microorganisms that are good for them.

But if you want to get rid of the algae completely, you should not depend solely on these fishes since there are better alternatives available.

Author note: Amano shrimp are the best algae eater for a guppy tank.

Final Thoughts

Guppies are colorful and adorable fishes that every aquarist wants to keep in their tank. 

They are one of the simplest species to breed and are a go-to choice for beginners. These fishes are really low-maintenance and do not require much attention.

However, they are perpetual feeders and keep eating algae even when enough fish food is given. Algae eating doesn’t have any adverse effect on their health, but it does hamper the oxygen supply in the fish tank. 

Hence, it is advisable that you keep your aquarium free from them. Now, that’s all that we had to share on the relationship between guppies and algae. 

Until next time! 

Guppy Dropsy 101 (Causes, Symptoms, Treatments and Prevention)

Guppy Dropsy

Available in a range of vibrant colors, Guppies are tropical freshwater fishes that have become popular due to their playfulness and peaceful nature. 

However, they are pretty vulnerable to various diseases, dropsy being the most dangerous among them. Therefore, it’s essential to pay attention to their maintenance requirements. In this guide, we will tell you all about Guppy dropsy and how you can prevent it. 

So, without further ado, let’s get started. 

What Is Guppy Dropsy?

Dropsy is a disease that affects guppy fishes and is marked by hugely swollen, oval-shaped bellies. In this condition, their stomach becomes bloated, and their scales protrude due to water or fluid retention in the gut or other internal organs.

If not treated at the outset, it proves to be fatal for the fish.

What Causes Dropsy In Guppies?

A weakened immune system leads to Guppy dropsy. If the fish has low immunity levels, a bacterium called Aeromonas infects and eventually kills them. However, this bacterium is always present in most aquarium settings, and it is only when your Guppies’ immunity levels are compromised that this microorganism can infect them. 

Several factors can lead to a weakened immune response in Guppies. We have listed some of them below. 

Poor Water Quality

The presence of decaying plant matter, old food particles, and dirty gravel can reduce the water quality. Moreover, excess ammonia and nitrates in the tank can lead to a spike and, eventually, tank poisoning. 

Stress And Injury

Stress caused by hostile tank mates is one of the leading causes of dropsy in Guppies. In addition, an injury sustained because of transportation from one tank to another can also lead to this disease. 

Poor Nutrition

If you are not feeding your Guppies the food they need, their immune system will weaken over time, and they will become vulnerable to attacks by bacteria. This results in the development of dropsy syndrome. 

Fluctuating Water Temperatures

A significant drop or rise in water temperatures can disrupt the balance inside the tank. Fluctuating temperatures will adversely impact the body of your fish and lead to stress and “temperature shock.” If not corrected, it can damage their organs and lead to a weakened immune system response. 

How To Tell If My Guppy Has Dropsy?

The symptoms of dropsy are very prominent but vary widely. We have listed the most common ones below.  

Pinecone Scales

One of the definite signs of dropsy is the appearance of pinecone-like scales. Since the belly becomes swollen, the scales can no longer stick to the sides of the fish’s body and protrude. 

Swollen Stomach

The infection can lead to a distended or massively swollen belly. Often, it is easy to confuse a bloated stomach with constipation or swim bladder disease, so look out for other signs to confirm if it is dropsy. 

Curved Spine

The pressure inside the Guppy’s body is so severe due to swelling of the stomach that it can bend its spine. Sometimes, the spine swells in a vertical direction, and this is more likely because of tuberculosis. In dropsy, the spine curves in a horizontal form. 

Other signs of dropsy include:

  • Bulging eyes
  • Fins clamped by the side
  • Discolored gills
  • Lack of movement and low appetite 

How To Cure Dropsy In Guppies?

Although the mortality rate for Guppies suffering from dropsy is high, if diagnosed early, the condition can be treated. So, here are the different approaches you can take to cure dropsy in your fish.


The first step towards treating your Guppy is to transfer it to a separate tank to reduce stress and allow focused treatment. Besides, it prevents the spread of infection to other fishes in the tank. 

Don’t make the quarantine tank smaller than the recommended size for Guppies, which is 5 gallons. Also, transfer some water from its previous tank to the new one so that the good bacteria is transferred to the quarantine tank, and your fish will not have to get accustomed to different water parameters. 

Aquarium Salt Treatment

Once your Guppy has been transferred to the “hospital tank,” it is time for the salt treatment. There are specifically formulated aquarium salts, but some aquarists also recommend using Epsom salt. 

As a rule of thumb, you should add one teaspoon of salt for every gallon of water. However, remember not to add more than the recommended dose of salt, as an excess of it can further disrupt the osmotic balance of the Guppy. 

Focus On High-Quality Diet

Since dropsy is primarily a result of a weak immune system, you should focus on feeding a high-quality diet to your Guppy. We recommend a balanced diet full of blanched vegetables, live food, and flakes. In addition, you should remove any uneaten food from the tank without fail to avoid the buildup of ammonia. 

How Do You Prevent Dropsy In Guppies?

As the old saying goes, prevention is better than cure. This especially holds true for dropsy, which is pretty challenging to treat. So, you must take certain steps to prevent your Guppies from contracting this disease. These include:

Maintaining A Clean Tank

Change the water in the tank often, clean the filter, and use a heater to balance the temperature inside the tank. All of these steps will prevent a nitrate or ammonia spike and keep bacteria at bay. 

Avoid Overcrowding

Don’t overcrowd the tank with too many fishes as it results in a higher bio-load. Besides, do not place aggressive tank mates with your Guppy. 

Don’t Overfeed The Fish

It is essential to feed high-quality food to your fish but don’t make the mistake of overfeeding them as it can result in swim bladder disease and constipation. 

Since Guppies are omnivores, maintain a balance between plant-based and animal-based food products. 


Is Guppy Dropsy Contagious To Other Fish?

Usually, dropsy is not contagious if the other fishes in the tank have a strong immune system. However, it is still advisable to shift the affected Guppy to a separate tank. 

Can Guppy Fish Recover From Dropsy Naturally?

It is highly unlikely that your fish will be able to recover from dropsy naturally. You need to treat it with salt, antibiotics and keep it in a separate tank. Even then, if the disease has reached advanced stages, recovery is unlikely. 

Is Guppy Pregnant Or Has Dropsy?

Female guppies have swollen bellies while pregnant, but if the swelling doesn’t decrease even after dropping the guppy fry, then it might be suffering from dropsy. 

To verify if it is dropsy, look for other symptoms such as discolored gills, curved spine, etc. 

Is Dropsy Painful For Guppies?

No. There is no evidence of dropsy being painful for Guppies. 


We hope this article has given you a complete overview of Guppy dropsy. Unfortunately, although this disease is treatable, in some cases, euthanization becomes the only option. So, it is always better to take adequate preventive steps to keep this infection miles away from your Guppies. 

Here’s a quick bit of advice before we go. You don’t need a fancy tank for your Guppy, but make sure it is spacious enough since these fishes thrive in a larger space. Besides, always look for suitable tank mates. 

With that, we come to the end of this guide. If properly taken care of, your Guppy will remain healthy for years to come!

The 5 Best Guppy Breeding Boxes for 2021

Best Guppy Breeding Boxes

When your guppies become pregnant, keeping the guppy fry alive is an essential part of the breeding process, as guppies are known to eat guppy fry once they’re born. Using a guppy breeding box, whether purchased or a homemade setup, is one of the easiest ways to ensure they survive.

A breeding tank is a separate container off of the primary aquarium that allows free-flowing water. It prevents adult fish from moving into the separate container and keeping the guppy fry safe.

There are plenty of excellent options for guppy fry breeding boxes, but here are some of the best.

Do I Need a Guppy Fry Breeding Box?

The short answer, yes! Guppy breeding boxes are an excellent alternative to creating a secondary aquarium when you have a pregnant guppy.

Save Money

Advantages of a breeding box include being less costly because you don’t need to invest in a second set of equipment, like filters and heaters.

More Convenient & Efficient 

It’s a more convenient option that requires less work, as you don’t have to work to match the water conditions. It’s also more efficient because you don’t need to waste time waiting for the secondary aquarium to complete a cycle before using it. 

Disadvantage of Guppy Breeding Box

The main disadvantage to a guppy breeder box is that it’s only a temporary fix. Guppy fry can’t be in the box for an extended period. Otherwise, it’ll begin to impede their growth. You should only keep your fry in there for two weeks or until they show signs of stress. 

You can then transfer them to an isolated tank or into your established tank if they are big enough. 

The Best Breeding Boxes for Guppy Fish Reviewed

With these pros and cons laid out, here are some of the top breeding boxes for your guppy fish:

The Alfie Pet Breeding and Hatchery Box

The Alfie Pet box is a hang-on breeding and hatchery box that sits inside the aquarium. It boasts a sturdy and functional design, has plenty of room for two adult fish inside. Water can flow through the box, and there is an attached separator.

It’s perfect for being a guppy fry nursery or a separate space for aggressive fish or fish that need to be protected.

There’s no heater, pump, or filter required for this model. It has an excellent design and is sturdy enough for each purpose. 

Alfie Pet - Rabea Hang-on Nursery Fish Tank with...
  • Dimension: 3" long; 3.5" wide and high.
  • Ideal as maturation tank for fry, or isolation tank for aggressive or injured fish.
  • Safely separates new-born fry from mother and other fish.
  • Space saving design that hangs on the inside of the aquarium.
  • Easy to assemble.

Marina Hang-On Breeding Box

This affordable hang-on breeding box is perfect for those who don’t want to invest in a filter or heater for a new aquarium. This particular model hangs off the exterior of the tank, and it has a multitude of uses. It has many uses, including a typical breeding box, a separate tank for isolation of adult fish, or an acclimation box.

Due to its excellent design, it’s incredibly convenient if any problems occur that you need to fix without disturbing the other fish. You can also easily monitor the guppy fry without disturbing tank mates. 

The breeding box holds around half a gallon of water, but you can choose other sizes if you feel you need larger. The primary aquarium water cycles through the box. You will need to purchase a separate air pump, which can run anywhere from $10 to $70.

This model includes three removable plates to create partitions so that you can have three separate sections for all your needs. 

Fluval Multi-Chamber Holding and Breeding Box,...
  • Compatible with Most Aquariums: Easily attaching to the side of most aquariums up to 1” thick, the...
  • Required Parts: Please note that this multi-chamber will require an Air Pump (1 L/per minute) and Airline...
  • Usage: Ideal as a hatchery and incubator to help protect newborn fry from being eaten (which improves...
  • Space-Saving: This chamber’s design measures 10.25″ L x 5.5″ W x 4.75″ H (26 x 14 x 12 cm) and...
  • Versatile: Utilizes the same conditioned water as your aquarium, no additional heater or filter required....

Pets Island Aquarium Fish Breeding Boxes

The Pets Island breeding box is placed into your aquarium and sticks to the glass with suction cups. The box has slits in the sides to allow for water flow, but they are small enough to keep the guppy fry inside.

The clear design allows for easy visibility to keep an eye on your guppy fry or separated fish. The lid is also transparent. 

Included with the box is a removable partition piece that can create two separate sections for your fish. The Pets Island breeding box is smaller in size, so it’s great as a temporary option and should not be used for guppy fry beyond two weeks.

It’s affordable and can be used for multiple purposes, so it’s an excellent option for those looking for a smaller box.

Finnex External Refugium Breeder Box with Water Pump

Purchasing a box that can be installed on the tank’s interior is excellent if you have a sizeable tank with adequate space for a box without causing stress to your other fish.

The Finnex box is another hang-on guppy breeding model that can be installed on the inside of your aquarium. It’s ideal for smaller aquariums that don’t have space for a box without impeding the other fish. The Finnex is a perfect solution for those who have limited space. 

Boxes installed on the outside of the tank are ideal for many reasons, including space-saving, easier to tend to maintenance, and easy to monitor your guppy fry or isolated fish. 

It can also be used as a refugium filter and can be great for both saltwater and freshwater aquariums. The included pump that comes with the breeder box is excellent at regulating the water flow.

It can also be manually adjusted so you can provide the best flow for your guppies. You can also install lights that clip on to create the best environment. 

The Finnex box comes with all the accessories you’ll need, so you won’t need to purchase additional equipment. 

Finnex External Refugium/Breeder Hang-On Box/Water...
  • Multifunction Box: Breeder Box, Refugium, Quarentine
  • Water Pump: Superior Water Flow
  • Water Pump Flow Adjustable
  • Dividers Included

XMHF Nylon Mesh Fish Fry Hatchery and Breeder Box

The XMHF Nylon Mesh breeding box is an extremely affordable alternative to other breeding boxes on the market. If you don’t have the materials at home to build your own, this is an option when you don’t want to spend a lot of money. It has a plastic frame that is surrounded by a mesh net. 

It attaches to the top of the inside of your aquarium with suction cups. When installing this breeding box, ensure the top of the net is above the top of the water. The net is used to keep the guppy fry separate from the mother and other adult fish. 

Since the box sits inside the established aquarium, you don’t need to purchase additional accessories like a heater or filter, and you don’t need to worry about keeping the water parameters in check for two aquariums. 

Along with housing guppy fry, the mesh box can house aggressive fish, injured fish, or weak fish from the others in the aquarium. It’s an excellent and affordable option and a great tool to have on hand if you ever need it. 

Nylon Mesh Fish Fry Hatchery Breeder Box...
  • Product Name: Aquarium Net Breeder
  • Color: White, Green; Material: Plastic, Nylon
  • Total Size: 17 x 12.6 x 15cm / 6.7" x 5" x 5.9" (L*W*H)
  • Package Content: 1 x Aquarium Net Breeder, 4 x Suction Cups
  • Net Weight: 80g

How to Save Your Baby Guppies Without Breeding Box

While a breeding box is an excellent and effective option, there are a couple of other methods that are doable if you worry about that breeder box causes too much undue stress.

Separate Tank

Having a separate tank set up for your pregnant guppies is a more expensive option than purchasing a breeding box or using live plants. If your aquarium is small, this may be the most suitable option for you.

A separate tank should mimic your established aquarium, with the same heater, plants, lights, filter, and same water conditions. 

Once your pregnant guppy is close to giving birth, you can remove her from your aquarium and put her in a separate tank. You can tell that she is getting close when her abdomen becomes enlarged and she becomes reclusive. 

Putting your pregnant guppy in a new tank can be a stressful ordeal, so transferring her carefully and keeping her environment as close to what she’s used to is key to a successful transition. Once she has the guppy fry, remove her from the separate tank and reintroduce her to the primary tank.

Once you have the guppy fry separated, you will need to take great care of them while growing. You will need to feed them properly with protein-rich foods like quality food and baby brine shrimp. Keep a strict feeding schedule. Guppy fry need to be fed frequently with small meals. 

(You may be interested to know how to care for baby guppies?)

Live Plants for Guppy Fry

Live Plants

If you have an established aquarium, you likely already have plenty of lush plants, which is part of an ideal guppy environment. Having a well-planned environment for guppy fry can help them hide and save them from being eaten by the adult fish. Recommended plant types include moss, frogbit, and guppy grass.

A DIY Guppy Fish Breeding Box

If you’re not looking to purchase a breeding box, you can create your own homemade setup for an affordable price. If you have a plastic container, a net, and rubber bands, you can build your own DIY breeding box. 

To create it, take a clean plastic container, put the mesh bag or net over the jar’s opening, and put a rubber band around it. Cut the plastic in half and place the meshed half onto the second half so that it’s face down. 

You will then have a container with two layers that can be secured and held together with your rubber bands. The upper portion of the container sits upside down inside the bottom container.

Fill the container with aquarium water and secure it to the aquarium side with some strong and water-resistant tape. Add some plants, and you can put the pregnant guppy inside your DIY breeding box. 

Once she gives birth, the guppy fry will automatically pass through the mesh netting, so they are separated, keeping the mother in the upper portion of the box. If you have all the necessary materials, a DIY breeding box is just as effective as a purchased one.

Here are some good tutorials:

DIY Guppy Fish Breeding Box: https://www.youtube.com/watch?v=VSTDOypTCm8

DIY Aquarium Breeder Box Fry Keeper: https://www.youtube.com/watch?v=4CfUDOz93Gw


When can I put a pregnant guppy in the breeding box?

Once you notice that her birth time is nearing, you can keep your pregnant guppies in the box. She should be removed 24 to 48 hours after giving birth to prevent her from eating the guppy fry.

How long should I keep guppy fry in the breeding box?

Baby guppies can be left in the box for up to two weeks for them to grow big enough so the adult fish cannot eat them. If you keep them in the box beyond two weeks, it may stunt their growth. If you ensure that the water conditions are optimal, you’re feeding them the best diet, and they are not showing signs of distress, you could keep them in the breeding box as long as you need.

Can two pregnant guppies share a breeder box?

Two pregnant guppies should not share a breeder box once they’ve given birth to give the guppy fry the best chance at survival.

How do I use a guppy breeding box?

A breeder box is the best defense from having the guppy fry eaten by the mother. Breeder boxes are relatively easy to use and maintain, even for new fish owners. The breeder box is a container that has two separate tanks, so when the guppy fry are born, they are separated from their mother, so she does not eat them.

The guppy fry are isolated from her, so they can grow big enough that they can’t fit inside the mouths of the bigger fish.

Can guppy fry die in the breeding box?

Unfortunately, there are many reasons why guppy fry die in the breeder box. To ensure you give your guppy fry the best chance at survival, keep them separate from their mother, keep the water conditions optimal and oxygenated, feed them healthily and adequately, and make sure they’re not stressed.

When can guppy fry leave the breeding box?

Guppy fry can stay in the breeder box until they are an adequate size to prevent being eaten by larger fish. As long as you have optimal water conditions and are not showing signs of stress, you can keep them in the box.

Do Guppies Lay Eggs? (3 Fun & Interesting Facts)

Do Guppies Lay Eggs

Guppies make good pets because they are fairly low maintenace, and they are really pretty to look at.  If you’re new to guppy fish keeping then one question you may be asking yourself is “do guppies lay eggs or give live birth?”

This is not a silly question, and many guppy enthusiasts have asked at one point or another. That’s why we thought it was a good idea to put together this helpful guide.

Do Guppies Lay Eggs?

Guppies do not lay eggs. Guppies are what are called “live-bearers” – they give birth to live young instead of laying eggs.

The majority of fish species lay eggs, with only 2% of fish species giving birth to live young rather than laying eggs.

Basically, the guppy eggs live inside of the mothers body and hatch inside her body. Only then are they released. 

So, rather than laying eggs and waiting for them to hatch, a female guppy releases live guppy babies (called guppy fry) into the water. 

A female guppy can give birth to between 10 and 120 guppy fry in 6 hours. That is a big range, and the amount of guppy fry depends on the individual mother.

Guppy Reproduction…How Does it Work?

Guppies reach sexual maturity at around 3 months of age. At this point, a guppy is ready to reproduce.

The gestation period of guppies, or the length of time that they are pregnant, is about 21-30 days

As mentioned previously, one guppy can give birth to 10-120 guppy fry at one time

All of these facts add up to guppies reproducing quickly, and often! They become mature enough to reproduce quickly, are not pregnant for long, and then can give birth to potentially a hundred babies at once!

Guppy have a tendency to eat their fry. Guppies do not care for their offspring like many animal parents do. Once the guppy fry are born, they are on their own!

It is likely that most, or all, of the fry will be eaten by the mother or by the mother or other inhabitants of the tank. Some of the fry may survive if there are enough hiding places in the tank. 

How often Can Guppies Give Birth?

Guppies are also somewhat unique in the sense that from a single encounter between a male and female guppy, the female guppy can store sperm in her body for her lifetime, which allows her to reproduce even if there is not a male in the vicinity.

Once guppies give birth, they can theoretically give birth again about 21-30 days later if they mate with a male. As mentioned previously, their gestation period is about 21-30 days.

This means that your female guppy may give birth as often as once a month. If you have more than one female guppy per tank, you may be seeing hundreds of guppy fry every month whether they are mating with males or just using stored sperm at a later date!

How to Control Guppy Population

Since guppies can reproduce so effectively, you may be concerned about limiting the guppy population in your tank.

For the most part, even if you have females who are giving birth to fry every month, the population is likely to limit itself provided that you have a few things in place.

Separate males and females

This is the most effective way to limit guppy reproduction. If guppies cannot mate, they are less likely to reproduce.

However, we know that this is not 100% foolproof. You may buy female guppies that are already pregnant, or ones that have stored sperm away for a later date.

So even if you get a tank of all females, they may have the potential to give birth!

Have only a male guppy

If you want to avoid guppy fry all together, see about getting just a male guppy. 

If you want several male guppies however, you may run into problems. If several male guppies live together without females, they can become aggressive and start fighting. 

Introduce a predator

Introducing a predator fish, such as a betta fish, will help to limit the population even if females do give birth.

The betta fish will eat many of the guppy fry which will help to limit the total population.

If you do go for a betta fish, be sure to get a single female. Males can be more aggressive and may bother the adult guppies, but a single female will help to limit the population without bothering the adult guppies.

Introducing a fish that is sure to eat it’s tankmates may sound mean, but it is all part of the circle of life. 

Get rid of hiding places

The guppy fry will survive if they have places to hide away from predators.

By limiting the hiding places (like live plants), the guppy fry won’t be able to get away from predators and the adult guppies (or betta if you decide to get one) will make food out of them.

Sell the guppies

If all else fails and you end up with a high population of guppy fry, you can try selling them.

Other people would probably love to buy your guppies, so try listing them for sale on your local buying and selling website.

You might also be interested in: How Much Do Guppies Cost?


Guppies can reproduce often and give birth to potentially a hundred offspring per month.

Female guppies can give birth to over a hundred guppy fry at one time, and can become pregnant immediately afterward. 

They have a short gestation period and can also store sperm for later use – so even if you have a tank of only females, they may give birth at some point!

For the most part, adult guppies and other predators in the tank will control this population by eating the guppy fry. Yes – adult guppies will eat their own babies!

But, if you let the guppy population go unchecked, you could theoretically end up with thousands of guppies in your tank in a short period of time!

Guppies make popular pets because they are so eye catching and usually make good tank mates. It might be worth it to get a single male guppy to add in to your tank to see how you like them at first! Then you can move on to adding female guppies and see how they do!

How To Breed Guppies Like A Boss!

How To Breed Guppies

Native to South America, guppies have been a staple of fish tanks for more than a century. You will find that guppies are commercially bred all throughout the water. This is because they can put up with a lot more than many other kinds of fish. That doesn’t mean they are invincible, but they are generally hardier fish as a rule.

There are also some who believe that guppies can be used as a means of controlling mosquito populations. However, nothing conclusive has been found in this arena, and it has historically been unsuccessful when tried.

How To Breed Guppies

Let’s get started on breeding guppies. This doesn’t entail anything too complicated, but there are still a few things you need to keep in mind.

Choosing Your Guppy Tank And Filtration System

While there are still a few more things about guppies specifically to cover, this is a good time to start gathering your supplies and tools. This extends to not only picking the right guppy tank for your babies, but also making sure you have a reliable filtration system.

Your breeding tank needs to be AT LEAST ten gallons. This ten gallon tank from Aqueon is a good example of what we are talking about. However, many experts believe a 20-gallon tank is in fact the best option for a beginner. We would agree. Twenty gallons gives you plenty of room to grow your interests. It also ensures plenty of room to move around for a modest collection of guppies and other fish, among the different components of your tank.

There are sizes larger than 20 gallons, in case you’re wondering.

Sponge filters are considered ideal. There are also uncovered systems that can be hung along the back of the tank, but these can actually kill guppies. A sponge filter not only offers mechanical and biological filtration capabilities simultaneously, but they won’t suck up any of your fish (cannisters and uncovered systems can do this).

Decorations And Substrate For Guppies

The next step will be to get your substrate, and then figure out the best/most enjoyable decorations to fill the space.

The substrate refers to the material that will be lining the bottom of your cage. Because guppies are such a durable species, the substrate can honestly be whatever you please. They do as well with gravel or sand, as they would with tile substrate products. You can even leave the bottom of the tank completely bare, if you please.

Just keep in mind that guppies often eat food that has fallen to the bottom of the tank. To that end, do not choose anything that is so fine, the guppies might eat it with their food.

In terms of decorations, you can mostly make your own choices in this arena. Males are notorious for harassing females, so we would suggest at least three or four large decorations. Not only does this give the females somewhere to hide, but it also breaks the line of sight between two different fish in the tank. This is important, as the males can actually harass the female guppies to death.

A Word About Saving Guppy Fry

Now, as a hopeful guppy breeder, you may want to make the following decision now: What to do about the baby guppies that are born in the tank, particularly in terms of the threat posed to them by adults.

Also known as fry, baby guppies are often mistaken for bits of food, after they are born. There are two basic responses to this fact. You can establish fry traps, which can help you to catch the babies before they’re eaten, or you can put down decorative plants. These tightly-knit areas can consist of java moss or something called guppy grass. Subwassertang is also very popular. Any of these can give you hiding spaces the adults won’t be able to reach.

The second option refers to something known as a fry trap. You can purchase your guppy fry trap outright, or you can learn how to make your own. Regardless of what you choose, you need to make a decision quickly, if you are going to breed. Check your solution regularly for any fry you need to move to another tank.

Some also choose to simply remove the mother, after she has given birth. This should be fine, as mother guppies do not contribute much of anything to the raising of their offspring. If anything, they can cause more problems.

Establishing Water Parameters

Water parameters are always important, when it comes to the fish you’re going to put in your tank. The high tolerance of guppies can shine here, but you should still keep certain essential water parameters in mind.

As a general rule, you should try to keep your ideal water for guppies pretty hard. The higher your pH levels, the harder the water is likely to be. The average pH for tap water is around 7.6. That is an ideal number for a guppy. You should also try to maintain a high degree of calcium with your water. This is essential for females in particular, as they need the calcium to remain strong while going through their breeding phase.

Don’t forget that a prime female gives birth to upwards of 30 fry in a single month. Crushed coral is a popular source of calcium.

Being able to measure your water accurately is important. Your TDS, also known as Total Dissolved Liquids, will tell you the amount of minerals and material (such as salt) that are in your water. Your gH refers to General Hardness more specifically measures the amount of magnesium and calcium in your water. 15-30gH is the ideal range. Then you have kH, which refers to carbonate hardness. This should be around 8.

Thankfully, testing kits for home aquariums make it easy to maintain the ideal levels. The temperature of the tank should always strive to be somewhere between seventy-eight and eighty-two degrees.

Time To Pick Your Breeders!

More likely than not, this is the part you have been looking forward to the most!

Once your tank has been properly cycled, with approximately 4ppm ammonia becoming nitrate within twenty-four hours, you can start shopping around for guppies. The first thing you need to keep in mind with this is that under no circumstances should you get just one male and female guppy. As we mentioned before, the males can chase a female to death.

However, you still need to keep a certain number of males and females in the tank at any given moment. Females guppies tend to be much larger overall than their male counterparts. The males tend to be more colorful, and this is particularly true in their tails.

An ideal guppy ratio for prospective breeders if two-to-one. That means two female guppies for every male in your tank. If you have a ten-gallon tank, start with approximately 1-2 male guppies and 3-5 female guppies. Even just a tank containing one male and two females can a good starting point. In fact, some experts say that’s exactly where you should begin.

“Which guppy strains are best for breeding?” is probably your next question. This is worth understanding, as well as other qualities you may want to be on the lookout for.

Are There Any Particular Guppy Strains Or Qualities To Look For?

You can decide ahead of time what you want to breed guppies for. Do you want to breed for color? Size? The shape of their fins? Some combination of the two? You don’t have to answer these now, particularly if you are new to all of this.

Our advice would be to use this guide to set up conditions for a beginner breeding experience. Gain some confidence, before you start aspiring to the most lucrative guppies to sell.

In general, you should look for guppies that offer the following characteristics:

  • Bright, appealing eyes.
  • Fins which are completely intact.
  • Coloration which could be described as bright or varied.

These are all indicators of a good strain. These are qualities you should look for regardless. However, if you are breeding with specific qualities in mind, there are a handful of other components which can be added to this fact.

Getting Started in Breeding Guppies

Guppies are an example of a livebearer. This means that they do not eggs. They will actually keep the guppies going inside of themselves, until the point in which the guppies are strong enough to swim and survive largely on their own.

Breeding is really quite straightforward. Once you have your guppies, and once your tank has been brought to the appropriate conditions for breeding, you can begin. After a day or two with 1 breeding male and approximately 2 breeding females, you should begin to see results. If you opt to have more than this number in your tank, it can get tricky to get fry which will offer the traits you’re trying to work towards.

Once your female guppy or guppies begin to give birth, they will probably continue to do so for anywhere from several months, to a full year. Remember that guppies menstruate, which means they will continue to live after their breeding prime has come and gone.

If the fry reveal the strain or qualities you desired, then there is nothing more to do than care for them. However, if you are breeding guppies for sale, and the strain you’re trying to recreate goes down in popularity, have those males and females separated at once!

It is also a good idea to try and get your males and female from the same strain. This is going to save you a ton of time. Even so, breeding for a specific strain can be challenging. You may want to do some research beyond what we’ve discussed here.

How To Take Care Of Your Guppies: When To Change Water

Although the hardiness of guppies is always appreciated, care is still important for healthy and happy guppies every step of the way. For example, how often should you change your water? This is essential for getting rid of the waste your guppies produce, which in turn can be extremely toxic to then.

If you only have a few guppies to start, you only need to change around thirty percent of the water in the tank once every week. Tap water should be fine, but a water conditioner attached to your tap is just as important to their health. A filter can get rid of undesirables like chlorine and assorted heavy metals. The water should also be at the same temperate point as the water in the tank.

How To Take Care Of Your Guppies: Feeding Time!

Feeding guppies is one of the most enjoyable aspects of keeping them in your space. The sight of dozens of adorable, flashy, alert guppies coming to the surface of the water for a tasty snack is one many owners love.

Learning how to feed guppies is pretty straightforward. For one thing, they enjoy a nice variety of food. The list currently includes frozen or live foods, vegie flake bits, or spirulina tabs. Some guppy owners even swear by giving them raw vegetables.

A good variety of the foods we mentioned above is perhaps best. They generally only need to be fed once per day, per the directions listed on the products you buy. Hikari USA Tropical Fancy Guppy For Pet Health, TetraMin Nutritionally Balanced Tropical Flake Food for Tropical Fish, and Omega One Super Color Flakes are all great examples of popular foods for guppies. Overfeeding can kill your fish with an abundance of ammonia.

How To Take Care Of Guppy Fry

If you don’t want to buy a water filter, consider changing out as much as fifty percent of your water each week. A thick substrate, as well as the presence of live plants, can also eliminate the need for a filter.

At this point, you should be ready to take care of your fry.

If you want to be a bit of a fanatic about feeding your fry the best food possible, consider freshly-hatched brine shrimp. As they are omnivores, guppies of any age will do best when maintain a good mixture of veggies and meats. Maintaining the best possible water tank conditions for guppies, which we have already discussed, will also go a long way.

If anything, getting guppy fry is a lot easier than managing an overpopulation problem. Too many guppies from breeding is a common problem many come across. This is certainly true in the beginning. If you need to get some population control measures enacted as quickly as possible, there are a number of potentially useful options you can explore.

What Do I Do If My Guppies Are Dying?

If you have a commonplace guppy strain, known for its hardiness, and the fry are dying off in great amounts, you have a problem.

In such a situation, you may find yourself dealing with bacterial infection or parasitic infection. Do you see any adults with unusually small stomachs? Do you see any small patches of white on them? These are two of the most common indicators of a problem. Broad spectrum medications, including antibiotic and antiparasitic options, are your best bet.

What Do I Need To Know About Chilling?

Ich or ick is a condition that comes with a high mortality rate. It can cause a decrease in appetite, as well as the behavior of rubbing their skin against rocks. The females becoming too cold can cause such an outbreak, so it is vitally important to keep those tank temps as high as possible.


These are the basics of guppy breeding and upkeep! Good luck and have fun!

Do Guppies Have Menopause? (An Interesting Answer)

Do guppies have menopause

When we think about guppies, menopause probably isn’t one of our initial thoughts. However, as a recent study indicated, female guppies do indeed experience menopause. This means there is more to their life than simply breeding and having babies. In general, as we have learned through studies just like the one mentioned, there is more to guppies than many people realize.

From the fact that female guppies experience menopause exactly as human females do, many compelling questions are beginning to emerge.

For example, why are some female animals continuing on past their optimal fertility years?

What Exactly Is Menopause?

Before we get deeper into the female guppy and menopause, let’s go over a brief definition of menopause.

Menopause refers to the natural leveling out of reproductive hormones in many female animals. This leveling out eventually gives way to decline. In the United States alone, more than 2 million new cases are diagnosed every year. Vaginal dryness, mood swings, and hot flashes are the most common symptoms. Various treatment options can be utilized, and most females who experience menopause do so without significant change to their lives. This thought extends to guppies. For any species, menopause marks the end of one’s reproductive years.

Symptoms generally lessen and/or disappear after four or five years.

What Does All Of This Mean For Guppies?

Guppies have always been grouped as animals whose purpose is fulfilled, once they have successfully extended their species. However, with this recent study showing us that the females go through menopause, this grouping no longer applies. Menstruation is a process which, among other things, tells us an animal, including humans, does not exist solely to breed.

Evolutionary theories aside, it is clear that female guppies have a role to play in their ecosystem, beyond the value of reproduction. This role can be potentially realized in several ways.

What Roles Do Guppies Fill Beyond Menopause?

This is where things can get interesting. If we believe that virtually everything in nature has a purpose, at any given stage of its lifespan, then it’s tempting to assume female guppies continue to be useful after their prime years of reproduction.

The notion of older female guppies acting as protectors for younger guppies is one theory that has been put forward. Many believe they have witnessed this behavior in action. Simply put, the older females are bigger, more easily visible, and are generally faster than their more youthful counterparts. All of these traits could be beneficial in the ecosystem of the guppy.

Keep in mind that this is just one possibility of many. Some believe female guppies simply exist after their reproductive years have passed, regardless of whether or not they have anything to contribute to the ecosystem.

This is something that will certainly require more study. Remember, this study was only released just fifteen years ago. That may sound like a lot of time, but studies such as these often demand a good deal of patience. Furthermore, there remains a sizable portion of individuals who are completely unaware that menopause occurs within female guppies.

What Happens To Female Guppies When They Enter Menopause?

If you do some research on guppies beyond this article, you will find a number of interesting anecdotes and facts about how they age. Particularly with the females, it has been said that you can always tell when they become menopausal. This, they say, is due to the older female guppy becoming fatter over time.

That is not altogether accurate. Yes, female guppies during menopause become bigger, but that doesn’t necessarily translate to becoming fatter. Many seem to become longer, as opposed to fatter. However, a certain amount of weight gain can still occur. It just doesn’t seem to be focused on the belly.

On average, guppies reproduce at a pace of roughly one litter every thirty days. This translates to approximately twenty litters of anywhere between thirty and fifty baby guppies. Beyond the astonishing fact that female guppies can have as many as one thousand babies in their lifespan, there does seem to a point in which this pace dramatically slows down. Older female guppies produce less as they approach menopause, compared to when they were younger. By a certain age, they seem to stop having babies altogether.

Yet they continue on.

A Few More Fascinating Facts About Guppies And Menopause

The 2005 study we cited at the top of this article has a few more fascinating elements to ponder.

A study conducted prior to the 2005 study showed the following: Guppies from areas with comparatively more predators than other guppies not only lived for a longer period time, but they also tend to start reproducing at a younger age, compared to guppies that lived in less risky areas. It was the mission of the 2005 study to figure out why this was occurring in the first place.

By the time the 2005 study had been completed, researchers were able to make a number of interesting predictions:

  • Female guppies do NOT provide maternal care to their babies, once they have given birth. The theory remains that female guppies can provide protection to younger guppies from predators, but this not a fully established proven concept, as we mentioned earlier.
  • “Fitness” is the term used by scientists to describe the ability of an animal to reproduce. From this specific perspective, researchers are still not clear on why female guppies continue to live after their reproductive years have concluded.

There is a theory that this is simply because the female guppy breaks down in different stages.

Conclusion: What We Definitively Know About Female Guppies And Menopause

By the way, the notion of older female guppies providing protection to younger females is known as the “grandmother effect.” The only species in which this behavior has been definitively found is in humans.

What we know for certain is that because female guppies continue to live full lives after their breeding years, their lives are not defined by natural selection. In other words, a guppy does not need to specific and constant biological function to justify its existence.

Pretty thought-provoking stuff!

How Much Do Guppies Cost? (Fancy, Mutt and Competition)


Guppies are the ultimate beginner fish. They are affordable, friendly, striking, and simple to care for. But not all guppies are created equal, nor do they cost the same! Guppies come in a large variety of amazing colors and patterns. They run the spectrum from plain grey with minimal finnage to incredibly beautiful guppies with elaborate finnage. 

When determining how much do guppies cost, the breeder takes into consideration exclusive traits, colors, and patterns. If you are wondering how much the average mutt guppy costs compared to fancy guppies, we will answer that question for you in this comprehensive guide. 

How Much Do Fancy Guppies Cost?

The price for fancy guppies can range in cost from $10 to $100 depending on the breeding and exclusive traits. A pair of Blue Delta Guppies will only cost you $9.00 compared to a pair of rare Black Moscow Guppies, which will cost you close to $90 from a breeder.

Fancy guppies have striking patterns and brilliant coloring that sets them apart from the average guppy fish. In addition to their coloring, fancy guppies will have long, flowing fins, and beautiful tails and patterns.

Generations of selective breeding go into creating these striking physical characteristics, which is why fancy guppies cost more than the average guppy. This selective breeding produces guppies that are not necessarily as sturdy as the average guppy fish may be. 

Because of this, breeding and raising fancy guppies might not best for you if you are a beginner. You will be required to engage in tank maintenance more frequently. Some fancy guppies are more sensitive to any changes in the water chemistry that sometimes occurs.

How Much Do Mutt Guppies Cost?

Mutt Guppies tend to be your average guppies. They’re guppies with unknown lines, which makes it difficult to identify which strain they are from. You can buy them at your favorite pet store.

Being unable to identify the particular strain a guppy fish comes from will directly affect its cost. Out of all the types of guppies, mutt guppies tend to cost less, only costing a few dollars each. For as low as $5.00, you can buy a pair for breeding.

Unlike the fancy guppies, mutt guppies are hardier and easier to care for. They adapt well to different water conditions and are easier to breed. This makes them perfect for a beginner aquarist.


How Much Do Competition Guppies Cost?

For a guppy fish to be considered a competition or show guppy, the guppy fish will need to have unique and striking physical traits that will best represent their species at a fish show.

The physical characteristics, as well as the strain of a competition Guppy, will determine the price, which can start anywhere from $20 and go as high as $100. 

Because competition guppies happen to be similar to fancy guppies in terms of physical traits and their lineage, they are usually priced similarly as well.

How to Breed Guppies for Profit?

There are several steps to breeding guppies for a profit:

Setting up the Tanks

If you plan to engage in selective breeding, you will need eight 10-gallon tanks. Each tank should be set up normally to accommodate your guppies. One of the tanks will be used as a reserve tank, while the other seven tanks will be used by each breeding pair. 

One tank should be for the first generation, another for the second generation, plus separate aquariums for the males and females, with the rest being for selected females and males.

You Need a Superior Breeding Pair

Obtaining a breeding pair of guppies that are of higher quality than the mutt guppies is essential when you plan to breed them for a profit. You can experiment with selective breeding to create your own fancy guppy strains that you can turn around and sell for a profit. 

For higher-quality Guppies, the breeder you purchase from should be able to show you a traceable and established lineage for each breeding pair. The pair you buy should be in excellent health, showcasing their vibrant colors and striking patterns. 

High-Quality Diets

When you are breeding guppies and raising fry, you need to give them a higher-quality diet, which will meet their needs nutritionally during every developmental stage. 

A well-balanced diet will prevent the kind of deformities that result from nutritional deficiencies. A good diet will also help them to develop more vibrant colors, as well as strengthening their immune systems, protecting them from certain diseases. A varied diet is best:

  • Premium flakes
  • Vegetable and organic matter (algae tabs, spirulina)
  • Live cultured foods (vinegar eels, daphnia, brine shrimp)

Monitoring and Recording

Before you begin selectively breeding your guppy fish, you need to have a breeding plan in place. Everything you do should be documented. 

The tanks should be numbered, as well as the fish within each tank. Keep track of the which fish parented which fish, and keep track of the siblings, as well. Keep a record of any breeding techniques you have tried and your results with each. Record each breeding date and the date of the delivery.

How to Improve Your Guppy's Overall Quality?

If you plan to produce higher quality guppies, you will need to begin with a pair that is of the highest quality. Make sure you are not trying to breed guppies with undesirable traits, deformities, and known diseases

Here are a few things you can do that will ensure the healthy breeding of your Guppies:

  • Use dechlorinated water when setting up each tank and changing the water
  • Maintain the tanks regularly, keeping the water conditions stable
  • Turn any artificial lights off at night so that the Guppies can rest
  • Be proactive in preventing diseases
  • Offer live plants in your tank
  • Eliminate any stress factors
  • A daily diet should consist of a variety of high-quality foods
  • Make sure your Guppies have the water volume and space they need 
  • Prevent premature breeding by separating the fry by size and gender


If you want to add interest and beauty to your tank, Guppies are a great way to do that because of their price and how easy they are to take care of. 

However, if you want to breed and show your guppy fish, you will need to invest more time and money than you normally would. But for fish enthusiasts, that extra price is well worth the rewards they get from breeding and showing fancy and competition guppies.