Pleco catfish are one of the most popular fish in the aquarium hobby. Especially bristlenose plecos and common plecos are popular among aquarists. Yet, these plecos are quite mysterious and there is still a  lot of misinformation available on their behavior. So, to pleco catfish bury themselves in the substrate?

Plecos are known to bury themselves on occasion. Especially common plecos do this, and they are known to dig their own breeding holes in the mud. Plecos will only bury themselves in fine gravel or sand and mainly do so to get under a rock or a piece of wood. In most cases, this behavior is caused by stress.

Types of plecos

Photo by J. N. Stuart

When it comes to wether plecos bury themselves, this highly depends on the species of pleco you have in your tank. This is because every pleco has a different natural habitat and behavior.

Smaller species are usually more calme in the aquarium and tend to dig less. Most of these species have plenty of other natural hiding spaces available in the wild and aren’t as used to digging theirselves a cave.

For example, L46 or Hypancistrus zebra lives in the Rio Xingù, in a habitat with lots of rocks and hiding places. No need to dig…

Bigger species might cause problems in your tank, especially if there are little to no hiding spaces or pleco caves available. Apart from their natural tendency to dig, these plecos are obviously stronger than their smaller cousins. Double trouble ;).

Substrate choice

Plecos prefer a sand substrate so they can easily scavenge the bottom layer looking for food. They only dig around in sand or in a fine gravel, because a bigger gravel will not be comfortable for them to hide in and is more difficult to move around.

Gravel also provides a better substrate for plants, because their roots can attach more easily in this gravel. So, if you’re having trouble with plants getting pulled out by your pleco gravel might be a better option.

Why do plecos dig in the substrate?

Plecos mainly dig to create hiding places, which is why you’ll most likely see them dig against hard structures like wood or rocks. This behavior is often caused by stress.

Plecos do have the ability change color. Nothing like an octopus though, but depending on the situation they can color more pale, which camouflages better in most substrates.

A pleco that’s digging mostly does so out of stress, so it can be quite easily resolved by taking a few measurements.

How to prevent a pleco from digging

The first thing to do is looking at your tank. In 90% of the cases, this is the problem. Here are a few questions to ask yourself:

Is the tank big enough? In a tank that’s too small a pleco will not feel comfortable, and often try to “escape” by digging or burying themselves. Especially for common plecos this a problem. Read: how to set up a pleco tank.

What color is the gravel? It might look good on photo, but for fish there’s nothing worse than a bright substrate. Flashy colors like blue, pink or yellow will stress out your pleco, causing abnormal behavior such as digging.

What are the tank mates? Plecos are mostly peaceful fish, but what about other fish that terrorize or attack them? Think about cichlids or barb species.

Are there hiding spaces? This is one of the most important things when keeping pleco catfish. Think about adding driftwood, rocks, live plants or even pleco caves. If you find your tank to not have a lot of hiding places where the pleco can fully hide, this will cause stress and the pleco will try to create its own hiding places.

You might think that adding hiding places will cause your pleco to hide more. And yes, the pleco will be less visible. But you have to ask yourself what’s best for the pleco. Ironically, plecos will even be more active with a lot of hiding spaces, because they feel safer.

If you want to know more about pleco catfish hiding and why they do, you can read our article regarding this matter.

Conclusion: do plecos dig?

Plecos can dig, but this is a rather rare behavior. Bigger species tend to dig more than small pleco species. 

If you find your pleco to be digging uncontrollably , this is most likely the cause of stress. Your tank might be too small, or it gets terrorized by tank mates. But most importantly, you need enough hiding places. Otherwise, the pleco will just try to create its own!