Assassin Snail Breeding (Eggs & Babies Care Guid)

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Assassin Snails (Clea helena) are one of the most popular critters in the aquarium hobby. They are prized in many tanks for the same reason: the ability to keep populations of pest snails in check.

As their name suggests, assassin snails are natural-born snail killers. They will consume just about any type of snail they can get their tentacles on – including their eggs! Additionally, they have a rather attractive appearance than many other snail species.

If you intend to breed assassin snails for profit or fun, there are a few important points to consider. In this guide, you’ll learn everything you need to know about assassin snail eggs, and babies care. It’s all here.

What Do Assassin Snail Eggs Look Like?

What Do Assassin Snail Eggs Look Like

The female assassin snail lays eggs individually in transparent egg capsules that are square in shape with a dimension of about 0.039 to 0.059 inches (1.0 to 1.5 mm). Unlike most other snails, each sac contains only one yellow egg. Interestingly, females usually deposit only 1 to 4 eggs per clutch in a straight line, spaced 0.19 inches (5 mm) apart. 

Where do Assassin Snails Lay Their Eggs?

These egg capsules deposit on hard surfaces, like rocks, driftwood, PVC pipe, and plant leaves; they are frequently seen in aquarium glass too.

How Long Does it Take for Assassin Snail Eggs to Hatch?

After assassin snail eggs are laid, it takes about 46-58 days for them to hatch at 77° F (25.0°C). Successful hatches usually occur when you notice empty eggs with open holes.

Despite its very low fertility rate, the assassin snail has a very high survival rate.

How Often Do Assassin Snails Lay Eggs?

There have been no reports (data) on assassin snail reproduction in the wild. However, they have been observed to lay eggs all year in a controlled laboratory environment.

How Fast Do Assassin Snails Grow?

Newly hatched juveniles are about 0.12 inches (3 mm) in size. They grow relatively slowly, and it takes assassin snails about 6 to 9 months to attain shell lengths of about 0.2 inches (5 mm).

In terms of the appearance of baby assassin snails, they resemble miniature adults with the same shell color and shape but lack the typical shell stripes. 

Assassin Snails Breeding

Assassin Snails Breeding

Assassin snails will breed in the home aquarium. Due to their very low fertility rate and the fact that assassin snail juveniles grow relatively slowly, it’s quite easy enough to be a fun project for any beginners without worrying about getting another snail infestation. 

If you do end up with too many, there are always ways to sell them or give away some unwanted assassin snails!

Unlike bladder snails (Physa acuta), the assassin snail (C. helena) is gonochoristic, meaning there are separate male and female assassin snails. To breed assassin snails, you will need at least one of each sex. This is another reason assassin snail infestations are not common in home aquariums, as it is difficult to accidentally introduce just a male and female together into an aquarium.

It is virtually impossible to determine the sex of your assassin snail since both sexes look identical in size and shape. Some owners suggest looking at the pattern difference that appears on other Buccinidae species, but this method is not clearly registered on Clea species.

Therefore, you will need to get a group of assassin snails that’s large enough (5-10 assassin snails) so that the chances of getting a couple of assassin snail is high. You’ll also need to feed them high-quality, nutrient-rich foods and provide them with a well-maintained aquarium environment to encourage breeding.

As with all snails, assassins are extremely sensitive to copper, so make sure any medications you use in your aquarium do not contain copper. Also, monitor copper levels in your aquarium if you use tap water to do water changes, as some municipal water supplies contain traces of copper.

Be beware of bladder snails. They are hermaphroditic, meaning each snail has both male and female reproductive organs. So these pest snails can reproduce on their own without the need for a mate. Moreover, they are notorious for mating with just about anything, including your assassin snails. Though assassin snails will kill them, their high reproductive rate (50 to 100 eggs each week) and egg hatching rate (close to 100 percent) can still lead to a bladder snail population explosion in your aquarium!

Unlike many snail-eating fishassassin snails don’t bother your fish, but they are brutal and may eat their eggs when they have a chance. IMHO, it’s best to keep only the pair in a small separate breeding tank with plenty of hiding places (e.g., driftwood, plants) to leave them be and let them spawn undisturbed. This way, you’ll be able to control their population as well.

The mating behavior of assassin snails mainly occurs at night, so it isn’t easy to observe. However, some aquarists have reported seeing the male assassin snail climbing over the females’ shell and staying there for a period of 20-30 minutes. During this time, the male just firmly grasps the female assassin snail’s shell with his tentacles and keeps still. After that, the male slightly slides down to the right side of the female and starts to search for the genital aperture.

If you just considered the breeding process an enjoyable project, all you need to do is get assassin snails of both sexes, and the assassin snails will do the rest! Still, it’s fun to watch assassin snail eggs hatch and see the baby assassin snails grow up!

For breeders who want to maximize the field of assassin snail, there are a few things you can do to increase your assassin snail’s growth rates.

First, keep your assassin snails well-fed with high-quality food. A nutritious diet will help assassin snails maintain their health and shell development, which is important for successful breeding. According to the research, the growth rates of assassin snail juveniles are significantly influenced by diet quality; A well-balanced that contains dry food and live prey will definitely speed up the assassin snail growth.

juveniles shell length reared at three different diets
Juveniles shell length reared at three different diets

Another factor that slightly affects their growth is the number of assassin snails in the aquarium. The stocking density experiment showed that assassin snails in a less crowded environment (5 snails/L) had a significantly faster growth rate than those in a crowded aquarium (20 snails/L) during their first month.

However, this trend was not observed in the second month. And the experiment also revealed the overall growth rate has no significant difference between assassin snails in different stocking densities. So don’t overdo it; just get a reasonable number of assassin snails for your aquarium.

Last but not least, provide them with a clean and stable aquarium with the correct water parameters. A significant shift in water temperature can lead to shell problems and death.

Wrapping Up

Whether you’re interested in breeding assassin snails for profit or just want to use their ability to get rid of pest snails in your aquarium, I hope you found this article helpful. 

Taking care of assassin snail eggs and babies is easy enough as long as you have a strong understanding of their basic needs. 

Have you ever tried breeding assassin snail before? How was your experience? Share your thoughts in the comment section below!

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Michele Taylor
Michele Taylor

Hello, fellow aquarists! My name is Michele Taylor, and I am a homeschool mother of six children, which includes five boys and one girl. My kids range in age from five-years-old to eighteen-years-old.

Growing up, our family had a large aquarium with angelfish, goldfish, and lots of different varieties of neons. We also had a “suckerfish” that grew to be about six inches long.

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