Apistogramma macmasteri (Red Shoulder Dwarf Cichlid) Care Guide & Species Profile

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There’s no denying that choosing a fish for your aquarium isn’t as simple as it may sound. If you are searching for an intriguing and beautiful dwarf cichlid who requires less maintenance time, then think no more and opt for the beautiful Red Shoulder Dwarf Cichlid.

Not only that, but they’re pretty robust and get along well with their tank mates, making them a go-to fish option for a peaceful South American community setup or a heavily planted aquarium.

While they are hardy and easy to care for, it doesn’t mean you should get one without the right knowledge base.

In this article, we will take an in-depth look at the Red Shoulder Dwarf Cichlid, including their appearance, diet, habitat, and tank mates.

Species Summary

The Apistogramma macmasteri (Red Shoulder Dwarf Cichlid) is, without a doubt, one of the beginner Apistogramma fish that are easy to care for and breed.

This Apistogramma species was named by the Swedish biologist Sven O. Kullander (1979) [1] in honor of Mark McMaster, a well-known aquarist who had popularized the species in the hobby during the early 1970s.

Apistogramma macmasteri is an endemic species found only in the upper Río Meta System in Colombia, where it inhabits the slow-flowing streams along the foothills of the Andean Cordillera, stretching from Villavicencio to Tame (Koslowski, 2002) [2].

These days, aquarists address this dwarf cichlid by several common names, including the “Red Neck Apisto” or “Red Shoulder Dwarf Cichlid,” as well as assigned A numbers: A120 and A121.

Apistogramma macmasteri taxonomy
Reference: Mike Wise

By far, this large Apisto is assembled in the A. macmasteri-subcomplex, A. macmasteri-complex, A. macmasteri-group within the regani lineage based on morphological similarities and geographic distribution. The A. macmasteri-subcomplex is an extremely species-rich group of Apistogramma, comprising two recognized species and more than 20 undescribed forms. 

Is Apistogramma macmasteri aggressive? Males of the A. macmasteri-group tend to employ a strictly polygamous reproductive strategy, meaning they often mate with every female present in their territory. They can be quite territorial and become highly aggressive towards females that are not yet ready to spawn during their spawning periods.

Scientific Name:Apistogramma Macmasteri
Common Name:Red Neck Apisto, Red Shoulder Dwarf Cichlid
A-numbers:A 120, A 121
Origin:Colombia (upper Río Meta system)
Care Level: Beginner
Lifespan:2 years
Size:2.8 inches (7cm)
pH:5.5 to 6.0
Temperature:76° – 80° F (24° – 27° C)
KH: <1º dGH
GH:<2º dKH
Conductivity (EC):<10µS/cm
Minimum tank size:20 gallons

Apistogramma macmasteri Types

Apistogramma Macmasteri

Two naturally occurring varieties are available among hobbyists: the Yellow color morph and the Red Shoulder (Rotrücken in German). The former is listed as A 120 and the latter as A 121. 

These two wild forms of A. macmasteri do not exhibit the intense colors seen in their captive-bred counterparts, which are the result of extensive selective breeding practices.

Due to their popularity, Apistogramma macmasteri have been readily bred in captivity, and the majority of fish commonly available to hobbyists are those red-shoulder variations. Here are several popular trading names:

  • Apistogramma macmasteri “Super Red”
  • Apistogramma macmasteri “Red Mask”
  • Apistogramma macmasteri “Red Neck”
  • Apistogramma macmasteri “Red Shoulder”

It is believed that these color-enhanced strains were developed by crossing the wild Red Shoulder form (A 121) with the A. viejita or more than one undescribed species in the A. macmasteri-group to enhance the vivid red body color, making it difficult to distinguish them from the domestically bred strains of A. viejita.

Additionally, man-made variations of the wild Yellow color morph (A 120) also exist; they are created to produce shiny gold coloring and are sold as:

  • Apistogramma macmasteri “Gold”
  • Apistogramma macmasteri “Gold Red Shoulder”
  • Apistogramma macmasteri “Red Neck Gold”
  • Apistogramma macmasteri “Gold Red Mask”
  • Apistogramma macmasteri “Platinum Red Shoulder”

No matter which forms you decide on, these fish look spectacular when kept in a well-maintained aquarium with the right water parameters and compatible tank mates. Keep reading to learn more about their care requirements!

A. viejita Vs. A. macmasteri

As mentioned above, A. macmasteri is easily mistaken for A. viejita (A 123). In fact, the true A. viejita is a very rare Apistogramma fish that is not captive-bred for commercial sale, but it is relished by professional breeders.

Many stores use the common name Red Neck Apisto and Red Edge Apisto to distinguish these two species. As their names suggest, the best way to identify Apistogramma macmasteri from Apistogramma viejita is by looking at the edges of their dorsal fin.

The male A. viejita has a dark top edge on its dorsal fin, while it’s absent in male A. macmasteri. In contrast, A. macmasteri develops extended tips on the caudal fin, and the spines on a dorsal fin are tipped with either silver, golden, or red.

Additionally, the body of A. macmasteri is relatively deep, and a “D” shaped spot adorns the caudal fin, whilst A. viejita sometimes shows a distinct spot in rectangular, trapezoid, or crescent.

Furthermore, A. viejita tends to be polychromatic with a wide range of color morphs.

Apistogramma macmasteri Size

The Apistogramma macmasteri is a relatively large species and can grow up to 2.8 inches (7 cm) in length. Males tend to be larger than females.


On average, Apistogramma macmasteri has a lifespan of approximately two years. Nevertheless, with exceptional care, they can survive up to five years.

The lifespan of these species is not something you can control, so do your best by offering them the best tank conditions and a well-balanced diet to reach the upper end of that range. 

Apistogramma macmasteri Care

Apistogramma macmasteri Care

In their natural habit, Apistogramma macmasteri can be found in shallow, slow-moving clear water and blackwater streams and tributaries where they hide among the submerged branches and leaf litter.

Similar to Apistogramma viejita, this robust dwarf cichlid is relatively undemanding when it comes to water conditions. Both fish settle well into a calm South American biotope tank.

However, it requires a decent amount of care to sustain for a long while. There are certain bare minimum things you have to offer them to make them feel comfortable in their new habitat. 

Here, we’ve mentioned the basic care guidelines you should consider before adding these colorful species to your tank. 

Tank Size

Apistogramma macmasteri males are strictly polygamous and are typically kept in small groups known as “harems,” consisting of one male and at least two or more females.

The tank size depends on the number of fish you want to keep. A minimum of 20 gallons long (30″ x 12″ x 12″) is recommended for keeping a trio.

Water Parameters

To ensure the well-being of wild-caught specimens, it is best to replicate the water conditions of their natural environment as closely as possible. More importantly, Apistogramma macmasteri requires a higher water temperature and is prone to several diseases at lower temperatures.

  • pH: 5.5 to 6.0
  • Temperature: 76° – 80° F (24° – 27° C)
  • GH: <1º dGH
  • KH: <2º dKH
  • Conductivity (EC): <10µS/cm

The good thing is that tank-raised individuals have the advantage of being hardy and adaptable to most untreated water values, making maintaining them less of a hassle.

As with all other Apistogramma species, the water should be kept clean. Perform water changes of 15 – 20% biweekly, more or less depending on bio load. For an overstocked aquarium, get yourself a reliable test kit to help you make sure the water parameters are in the ideal range.

In the wild, A. macmasteri prefer still and slow-moving water, so they should not be exposed to strong currents. Multiple small sponge filters are a simple and cost-effective way to create the kind of water movement that these fish need. 

Decor (Plants and Substrate)

These dwarf cichlids are often found in the regions where the substrate comprises leaf litter. Hence, you should add dense plantings and ample hiding spaces, like Catappa (Indian Almond) leaves, PVC tubing, caves, rocksand so on. A soft sandy or fine gravel substrate is recommended.

Dim lighting is preferred for these bottom dwellers. You can also add live plants. Species from Microsorum, Cryptocoryne, Microsorum, and more are all great options.


Apistogramma macmasteri are natural carnivores. In the wild, their diet consists primarily of smaller invertebrates at the bottom of the creek.

In the aquarium, they can be offered a variety of high-quality frozen and live foods. These include Daphnia, mosquito larvae, glassworms, bloodworms, and newly hatched brine shrimp.

Most Apisto enthusiasts concur with Dr. Alan DeAngelo (1991) [3] in suggesting that Tubifex and Blackworms should be disregarded for Apistos because of their lack of cleanliness. The same goes for frozen brine shrimp, which can be found almost everywhere in the tank.

Tank-raised A. macmasteri readily accept fine, sinking flake foods. However, note that many dwarf cichlid breeders only feed their fish live food. This is because they are more nutritious and beneficial for the fish’s coloration and health. As a result, these fish are picky eaters and may refuse to eat dry foods.

Feed the fish 2 – 3 times daily with small portions, and be sure not to overfeed them.

Apistogramma macmasteri tank mates

For optimal conditions for wild-caught Red shoulder dwarf cichlids, it is highly recommended to keep them in species-only aquariums in large groups consisting of at least three males and 4-5 females. This approach not only allows you to observe the diverse social behavior of dwarf cichlids but also increases the likelihood of obtaining breeding pairs. Surface-dwelling dither fish are good tankmates.

Tank-raised specimens can also be kept successfully with other peaceful fish species of similar size and water requirements. Avoid keeping them with larger or more aggressive bottom-dwelling fishes as well as other Apistogramma species from similar groups to avoid hybrids.

The possible tank mates include: 

Apistogramma macmasteri Male Vs. Female

In Apistogramma macmasteri, gender differences are easily noticeable. Typically, males have a longer dorsal fin with serrated hard spines and pointed tips on both lobes of the round caudal fin.


The Red Shoulder Dwarf Cichlid (Apistogramma macmasteri) is often recommended for beginners due to its ability to breed without needing the very specific water conditions of its natural biotope.

Remember to place a male with at least two females in a separate breeding tank.

In terms of water parameters for breeding, these fish have been successfully bred in an aquarium with soft to moderately hard and slightly acidic water.

Being a secretive cave spawner, you should provide plenty of caves in the tank. The male Apistogramma macmasteri often services more than one female, and each female needs a suitable spawning site.

Reproduction in Apistogramma macmasteri is typically initiated by the female, who can produce 60-120 eggs attached to the ceiling of caves. While the female guards the eggs, the male defends the harem territory.

After three days, the eggs hatch, and the fry become free-swimming in 4-7 days. Newly hatched brine shrimp can be used as their first food.

Sometimes, spawn occurs secretly until the fry are found in the tank. In such cases, the male may need to be removed as the female can become very protective and may attack him.

Where to Buy Apistogramma macmasteri 

Apistogramma macmasteri is a staple species in the fish trade, and it is affordable and widely available in local fish stores and online.

Final Thoughts 

That’s all about Apistogramma macmasteri care guidelines. We hope our in-depth research will help you learn more about these colorful dwarf cichlids.

These species may become a bit territorial and demand extra attention when spawning, so take the best care of them in their hour of need.

These look fabulous when kept in a tank with other species and add a unique spark to your South American cichlid aquarium. Moreover, they are fun to observe and offer a truly rewarding experience. 

If you have any questions about keeping these cichlids or want to share your experience with us, feel free to leave a comment below. 


  1. Kullander, Sven. 1979. Species of Apistogramma (Teleostei, Cichlidae) from the Orinoco Drainage Basin, South America, with Descriptions of Four New Species
  2. Die Buntbarsche Südamerikas 02. Apistogramma und Co. Hardcover – October 1, 2002
  3. Dr. Alan DeAngelo interview
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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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