Aqua Fauna Research Logo

Do Plecostomus Eat Snails

Author: Nicole Malczan

Snails make a good choice for aquariums as they feed on decay, detritus, and old vegetation. Rabbit snails, nerite snails, apple snails, and ramshorn snails are ideal for these purposes especially. Yet lately your snails are disappearing from your tank one by one, and you suspect your Plecostomus could have something to do with it. Do Plecos eat snails?

The Plecostomus will indeed eat snails, although not typically. If you’re not feeding your Pleco enough, it might feel inclined to go after a snail. Once a Pleco begins eating snails, it could continue the behavior and develop a taste for them.

In this article, we’ll discuss further why your Pleco might eat snails, what the fish should be eating instead, and if snails are by any means nutritious for a growing Plecostomus. We’ll even offer some suggestions for getting your Pleco to stop this bad behavior. You’re not going to want to miss it!

Does Plecostomus Eat Snails? What Is the Plecostomus Diet?

If this is your first Plecostomus, you might not be sure what its diet is supposed to consist of. Although Plecos can eat snails, that’s not a normal part of their diet. Here’s what you should incorporate in their day-to-day eating habits instead.


The bulk of a Pleco’s diet is algae. Yes, that’s it. A fish aquarium can start growing algae within two weeks, maybe a month after you last cleaned it. With a Plecostomus in your tank, it’ll clean up most of the algae, and quite hungrily at that. This doesn’t mean you should go without cleaning your tank, as your fish and snails won’t appreciate that.

Algae pellets are a good way to ensure your Pleco gets its daily supply of algae but without letting your tank get overrun with the green stuff. Sinking algae wafers will let the Pleco feed at the bottom of the tank, which is something this fish species likes to do.

Occasional Treats

You don’t only have to feed your Pleco algae day in and day out. About once a week, maybe twice a week if your fish is well-behaved, you can give the Plecostomus a treat. No, this treat is not snails, but rather, raw cucumbers or zucchini. You want to put the veggies lower in the tank so your Pleco spots them before another fish does.


Some Plecos need driftwood, which you don’t technically feed to your fish. Instead, put some driftwood in the tank and every now and again and your Plecostomus will begin munching on it. Driftwood is a natural source of fiber, so eating it ensures your fish is healthy.

The Pleco needs to be given food daily to stay alive. You might want to save your feeding period until the nighttime, as Plecos rarely eat during the day.

Which Snails Does the Plecostomus Eat?

The Plecostomus, if driven to eat snails, will consume any ones you happen to have in the tank. Here are the most common snail species that live in aquariums.

Rabbit Snails

This snail is also often referred to as the elephant snail due to its long head, which almost resembles an elephant’s tusk. Bright yellow, the rabbit snail has a natural curiosity for the world around it and will not cause a fuss with other fish in the tank.

Rabbit snails eat all sorts of food, including blanched green zucchini, spinach, lettuce, frozen bloodworms, algae pellets or wafers, earthworm pellets, Spirulina tablets, and shrimp food flakes.

Nerite Snails

Teeny-tiny snails, the exterior shell patterning and coloring of a nerite snail will decorate any fish tank. These snails feed on algae. Their small size lets them clean up algae from aquarium décor, substrate, and glass.

You also don’t have to worry about the nerite snail reproducing like crazy, as it needs other sources of water besides freshwater to mate. This means if you buy one nerite snail, you’ll still have only one several months from now.

Apple Snails

The Ampullariidae or apple snail is a large snail (about the size of an adult human open palm) that will scavenge throughout your fish tank for detritus and algae. They like other plant sources too, but apple snails will not attempt to eat your fish. The same should be true vice-versa for the most part.

Ramshorn Snails

The last type of snail common in fish aquariums is the ramshorn snail. This freshwater snail species eat zucchini, spinach, green lettuce, and algae, even brown algae that develop beneath the substrate. Some ramshorn snails have been known to attempt to eat any living plants in the tank, but this doesn’t happen often.

Why Does Plecostomus Eat Snails?

Okay, so the Plecostomus isn’t super picky about which snail species it eats, but why does it go after snails in the first place?

To reiterate what we said in the intro, this isn’t a frequent occurrence. Snails are not a part of a healthy Pleco’s diet, so if your fish is eating snails, you have to step back and ask yourself why. More than likely, it’s because the Pleco is hungry. As mentioned, you have to feed your Pleco every day.

What if you do feed your Plecostomus daily but it’s still eating snails? You might not be feeding it enough. Increase its quantity of food for a few days and see if that makes a difference. A starving Pleco will look for food wherever it can get it, including snails.

The problem with a Plecostomus that eats snails is that it tends to develop a taste for them, and then it wants to eat more. Any snail you put in your fish tank with the Pleco could be a goner, which is no good. Snails are useful cleaners in your aquarium, so you want the snails and your Plecostomus to coexist.

Another reason the Pleco could go after the snails in the tank is that they’re competing over food sources. Remember, the staple of a Plecostomus diet is algae, be that algae growing in the tank or in pellet or wafer or tablet form. The snail species we covered in the last section will also eat algae in all its forms. If the Pleco feels threatened because some other creature is eating its food, the Pleco might be inclined to pick off the snails so it doesn’t have to compete for its next meal.

Does Your Plecostomus Eat Snails When They’re Dead or Alive?

If a Pleco eats snails, does it prefer them alive or dead? Honestly, it doesn’t really matter to the Plecostomus. If the Pleco does decide to eat a living snail, it’s been known to suck the snail right out of its shell, which is pretty grisly. Plecos are large fish, especially compared to a snail, so it doesn’t take much effort for them to remove snails this way.

Remember also that the Plecostomus is a bottom-feeder, so it will happily feed on whatever is lingering at the bottom of the tank. If that happens to be a dead apple snail or a rabbit snail, the Pleco won’t care.

This doesn’t necessarily mean that your Pleco killed the snail. Your snail could have died of natural causes or another fish could have done it. The Plecostomus is just taking care of cleanup. Still, if your Pleco has resorted to eating dead snails, you really need to look at its diet and how much (or little) you’re feeding it each day.

Do Snails Provide Nutritional Value to the Plecostomus?

Are snails at least a healthy part of a fish’s diet? Sure! Raw snails contain about 20 percent of copper, 27 percent of phosphorus, 7 percent of niacin, 7 percent of vitamin B6, 1 percent of thiamin, 1 percent of calcium, and 2 percent of vitamin A. They’ve got a good amount of protein, about 16.1 grams per 100 grams of snail.

Although snails are indeed a tasty, even nutritious treat, they’re still not something a Pleco should eat. That goes for the eggs of snails too, which the Plecostomus typically ignores, likely because the eggs aren’t meaty enough to satiate their appetites.

How to Stop Your Plecostomus from Eating Snails

If your Pleco has gone through its fourth snail of the month, something needs to change. What can you do to discourage your Plecostomus from eating the snails in your fish tank? Here are some suggestions.

Feed Your Snails at a Different Time Than the Pleco

Snails and Plecostomus might both like algae, but you can prevent the two species from competing for food in one very easy way. Since the Plecostomus is dormant during the day, feed your snails their algae then. It’s unlikely the Pleco will attempt to fight for the food.

Prevent Overcrowding

The Plecostomus can grow 24 inches long, so it needs a tank that’s at least 75 gallons, even 80 gallons if you can swing it. Providing a tank that’s too small will make the Pleco feel even more territorial than it usually does. If any other animal begins going after its food source, it might eat that threat, including snails.

Keep Your Plecostomus Fed

We really can’t say this enough, but a well-fed Pleco will feel far less inclined to munch on the snails that are cleaning up your fish tank.


The Plecostomus has been known to eat snails but on rare occasions. If yours is noshing on dead snails or pulling live ones out of their shells, it’s likely because the Pleco is hungry. The fish might also be competing against the snails for algae, which can be remedied by feeding your Plecostomus at different times than the snails. Best of luck with your Pleco!