Do Fish Eat Sand? Yes, And Here’s Why

Are you a fish lover? Do you love watching fish swim in an aquarium? Then you must have noticed something natural yet weird about them. Do you know what I’m talking about? Let’s see.

You would sometimes find sand substrate in a fish’s mouth when you organize your substrate to make space in your aquarium. As you watch them eating the sand and spitting it out later, you’d wonder, is eating sand normal behavior for a fish, or is it fishy.

do fish eat sand

So, do fish eat sand? Yes. Fish eat sand. But this isn’t true for all species of fish. Only certain species have the appetite to eat sand.

Fish eat sand to help them with digestion. The particles present in the sand help them properly digest their food.

Don’t worry. I’m not throwing words out of just anywhere. There are actual facts that belong to science. You should know that certain exotic fish eat the sand substrate to aid their digestion. Later, they spit out the same sand and save themselves from any potential risks of swallowing sand.

Now that you know about fish eating sand, let me tell you another thing about it.

Why Do Fish Eat Sand?

Fish eat sand to help aid them with digesting. Some fish also munch on sand so that they can consume the tiny algae that grows on it.

Which Fishes Eat Sand?

I recently bought a fish tank a couple of months back and have seven fish in them, all different species. I made a habitat for them with sand instead of rocks and gravel. Well, the sand looks so much better in an aquarium with a few pebbles along with plants and leaves.

So, as days went by, I started noticing that few fish were eating the sand in the aquarium. I decided to wait a few days to see if all the fish started feeding on the sand.

However, I noticed that the same fish were eating the sand over time, and the rest weren’t.

I ran my research and asked my fellow fish lovers about the same. That’s when I learned that not all fish eat sand. Additionally, they do not eat sand like a food item. Instead, it would be better if you say that the fish use the sand for beneficial purposes.

The sand helps them with digestion. The fishes don’t really eat them, instead they munch on it for some time and then spit it out later.

Not all fish does the same. A few fish, such as Synodontis Lucipinnis, Geophagus, Cichlids, Goldfish, Catfish, Loaches, Corydoras, and Shrimp, are a few sand-eating fish.

Fish like Gobies and Dragonfish are sand-shifters. They gulp a huge mouthful of sand, pass it through their gills to the operculum and sieve it out the critters that they eat. This helps them in digestion. That is why you should keep your fish on the proper substrate, since its more than just the base for them.

Saltwater fish and Parrotfish eat the algae present on the ricks that take the form of sand later on. It passes through their digestive system and comes out as poop.

(Aside: You should see a school of parrotfish grazing. I can tell you it is one of the prettiest sights and the noisiest sound at the same time.)

Can Sand Be Harmful To A Fish to Eat?

Sand can be anything but harmful to a fish.

However, you should know that this is applicable only if the fish is a sand-eating fish. The ones who do not have an appetite for sand, may be harmed if they accidentally it.

For such fishes, ingesting sand can affect their digestive system by eating sand accidentally. It may also affect their respiratory system. In the worst-case scenarios, some fish may even die in such occurrences.

Wrapping Up

Fish eat sand. However, not all fish are compatible with sand substrate. Therefore, if you plan upon getting an aquarium, be informed of the correct substrate to house your fishes.

This way, you’d have a beautiful aquarium filled with beautiful fishes that would enjoy their time!