Are Plecos Scaleless?

Plecos are scaleless fish that belong to the armored catfish family. Instead, their bodies are covered by bony scutes to provide protection. The scutes cover the upper part of the head and the abdomen, but the lower part of the head and abdomen remain soft and exposed. 

In this article, we’ll talk more about the bony plates on the bodies of plecos, why they sometimes lose them, and other types of scaleless fish you can keep in a tank. So, keep reading to learn more about this topic.

Are Plecos Scaleless?

Plecos are scaleless because their bodies are covered in bony plates. These bony scutes provide protection from predatory fish, helping plecos to survive and live for longer periods.

The scutes protect fish from parasitic infections, physical trauma, and the attacks of other fish.

Albino Pleco Close Up

Do All Fish Have Scales?

There are several fish species that don’t have scales like plecos. In general, fish are grouped according to their skeletal structure, but you can also divide them into scaled and scaleless fish.

Scaleless fish aren’t that common because the scales provide a layer of protection. However, some fish have bony scutes instead of these scales.

On the other hand, some fish have smooth bodies covered in a slime coating, while others can have tiny scales that you might not be able to see. Here are some types of scaleless fish.

Conger Eel

This fish can reach a maximum length of 6 feet. It has thick skin with glands that produce mucins and proteins to create a slime coating. These bottom feeders feed on crustaceans and fish that live at the bottom of the sea.

Sea Lamprey

Sea lampreys have snake-like bodies with small fins that allow them to propel their bodies forward. Instead of jaws, they have suction-cup-shaped mouths that allow them to attach themselves to different surfaces.

These fish are considered parasites because they latch onto other marine animals and suck their blood.

Pacific Hagfish

This is another fish with a snake-like body and no fins. Pacific hagfish have barbels around the mouth and small teeth.

Their skin looks different from other fish, with muscle fibers embedded within it. They’re used in the fashion industry to make various fashionable items.

Black Bullhead Catfish

This catfish has a soft body covered in a thick layer of slime. Just like other types of catfish, this one has barbels on the mouth and mainly feeds on other fish.

Rat Fish

Also known as rabbitfish, this fish has a large head attached to its small body. This fish lives in the deep waters at the bottom of the ocean and generally feeds on small crustaceans and algae. It’s rather difficult to study because it lives at great depths.

Do Plecos Shed Their Skin?

Plecos don’t shed their bony scutes, but they shed a layer of the protective slime coating that covers their bodies. This can happen for various reasons.

  • Plecos shed their slime coating as a natural part of the growing process. The fast currents in their natural habitat help remove the extra layer of slime, and it accumulates at the bottom of the tank.
  • Keeping faster bottom feeders in the same tank with the plecos will stress these fish. They’ll start to produce more slime to compensate for any injuries, and eventually, the extra slime coating will sit at the bottom of the tank.
  • In a small tank, plecos can be too stressed because they don’t have enough space to swim, and they’ll start to shed their slime coating.
  • Without enough hiding spots, plecos will have slime buildup, which leads to excessive shedding.
  • The absence of aquatic plants, shipwrecks, caves, and driftwood will reduce the number of shaded areas in the tank. The shade boosts plecos’ immune system and reduces slime shedding.
  • A sudden change in the water parameters like the temperature and pH level can cause the plecos to lose their slime coat and some of their scutes.
  • Not having enough food in the tank can lead to the fast accumulation and shedding of slime. In addition, plecos are slow swimmers and will often lose the competition when they’re competing for food with other bottom feeders.

Should I Worry if My Pleco is Shedding?

Shedding the slime coating that covers the fish’s body is quite natural and doesn’t mean that there’s something wrong with it. In general, plecos are able to repair their damaged scutes to keep their bodies healthy.

However, if shedding slime and losing scutes is excessive or happens all the time, then there might be a problem. Your pleco can be extremely sick or suffering from a bad infection or bloating.

If you notice that there are several damaged scutes on the fish’s body, there might be a problem in the tank’s setup. Other aggressive fish might have attacked your pleco in the tank.

Derek Ramsey (Ram-Man) [CC-BY-SA-3.0]

Do Fish Scales Grow Back?

Fish that have scales on their bodies can lose them due to physical injury, aggression with other fish in the tank, or a serious infection. However, in most cases, fish are able to grow their scales back.

The time the scales take to grow back depends on the fish species and their health.

If your fish isn’t healthy, the scales might grow back at a slower rate. They can also grow smaller than the fish’s original ones.

However, if the fish lost a lot of scales due to a fight with an aggressive fish, it might not be able to regrow all its scales. In this case, the fish will be prone to future infections and injuries, and it will eventually die.

Wrap Up

Plecos are scaleless fish as they have bony scutes that grow to cover the upper part of their bodies. The rest of the body is covered in a slime coating that protects the fish from injuries and infections.

There are several scaleless fish, but they’re less common than fish with scales. Fish that have scales can also lose their scales because of physical injuries or diseases. However, in most cases, they’re able to grow them back.