Plecostomus or common pleco (Hypostomus plecostomus)

Common pleco (lat. Hypostomus plecostomus) is a type of suckermouth catfish, which is often encountered in home aquaria. Many aquarists have had this fish or saw it on sale. This is a perfect tank cleaner, plus it is one of the most enduring and undemanding kind of catfish, but…

Habitat in the wild

It is prevalent in tropical waters of central and South America, in Amazon River basin (Brazil, Guyana, Suriname, Trinidad). The fish dwells in oxygen-rich lotic waters and in brackish waters of river estuaries.

Can live in various conditions of tropical forests. Such unexpected adaptability to completely different environmental conditions was developed by the fish during its evolution and thus guaranteed that the fish has well-developed survival mechanisms.

One of the special mechanisms is its suckermouth. With its help plecostomus can not only collect food and various waste from the bottom, but also fix itself at some place by holding with its suckermouth to the surface.

This gives the fish a chance to stay on its territory during rain season, while fishes that are less adapted to such conditions are carried away downstream by strong water flow.

During dry season when many waters get dry, another adaptive mechanism helps this catfish to survive – this is the ability to take in oxygen from atmospheric air.

This is due to a special structure of the fish intestinal tract, that is penetrated by lots of capillary tubes. According to some reports this catfish can stay out of water for up to 30 hours.


The length of the body reaches 60 cm (24 inches) (in a tank it is up to 30 cm (15 inches long). Its lifespan is about 12-15 years.

The head of the suckermouth catfish is big; the eyes are small and high-set. There is a membrane on the eyes, it is like a microscope or photo camera diaphragm – it allows to control the light level that gets into the eye: during the day it covers almost the whole eye and at night it gradually opens.

The body is elongated and covered with 4 rows of bone plates. The body bottom and the abdomen don’t have them. The first ray of the dorsal has sharp spines. Dorsal, pectoral and tail fins are well-developed.

The dorsal fin is high and long (1 coarse and 7 soft rays). The anal fin consists of one coarse and 3-5 soft rays. The tail fin is moon-shaped, the bottom part is longer.

The body coloring is gray-brown or brown with green tint; it has a pattern made of dark spots and stripes.

Difficulties in keeping

This catfish may be a troublesome tank dweller for an aquarist. Usually plecostomus is bought as a juvenile, when it is about 5-10 cm (2-4 inches) long. But it grows fast and can become up to 60 cm (24 inches) long, though in tanks it is as a rule about 30 cm (15 inches) long.

This catfish is easy to keep in a tank provided with a diet rich in algae or fed with special food for catfish. However, due to its size the fish won’t do for beginner aquarists, since it requires large tanks.

Tank water parameters aren’t that important, the main thing is that the water should be clean. Be ready to get a big tank, since plecostomus grows fast.

Care and keeping in a tank

Scientific NameHypostomus plecostomus
Common NamePlecostomus, common pleco, suckermouth catfish, pleco fish,
Tank size300 liters and more
DietOmnivorous bottom feeders
Temperature24 — 26 °C (75-78°F)
Sizeup to 60 cm (24 inches)

The fish is a bottom dweller. It is timid and during the day it hides under snags or in caves. It is active in the twilight and at night. May spend large amount of time mowing on its fins between the tank plants and shelters.

You should put some snags, stones and other shelters into the tank – the fish will hide there during the day. Snags in a tank are not only shelters for the fish, but also this is where algae grows fast and they also contain cellulose that the fish needs to have good digestion.

Tank volume is important for plecostomus. It should be at least 300 liters large and as the fish grows, it’ll need a bigger tank – up to 800-1000 liters capacity.

Once again, the fish grows very fast and it needs space to swim and feed.

It likes thickly planted tanks, but it may eat tank plants with soft leaves or accidentally pull out some large plants. You must keep the tank covered all the time – the fish tends to jump out of water.

As we mentioned above, tank water parameters aren’t crucial. The water has to be clean with efficient filtration and regular renews, since considering the size it produces quite a lot of organic waste.

Required water temperature is 24 — 26 °C (75-78°F), ph: 6.5-8.0, hardness 1 — 25 dGH.


The fish mainly eats vegetable food and algae, though it may eat some live food. It may eat some soft leaved tank plants, but only in case if it doesn’t have enough of algae and supplements to its diet.

To keep the fish you need a tank with large amount of fouling in it. If the fish eats algae faster than it appears, you should feed it with artificial food.

As for the vegetables, you can feed fish with spinach, lettuce, squash, cucumbers. As for the live food, it can be earthworms, bloodworms, insects larvae, small crustaceans. It’s better to feed in the evening shortly before you turn off the tank lights.

All pleco have this peculiarity of keeping in a tank – they need cellulose for their digestive system to function properly. In the wild they get it by scraping algae from snags, but they don’t always have this ability in tanks. So, put a snag into a tank.

Tank mates

This is a nocturnal fish. It is peaceful when it’s young, but it becomes quite quarrelsome and territory dependent as an adult. May live peacefully with its kind, if they grew together in one tank, but if they fight, it is till the weakest one dies.

May nip scales from discus fish, angelfishes while they sleep. You can keep juveniles in a community tank, however, it is better to keep the adult species in a separate tank or together with other large fish species.

As a rule pleco tank mates are large cichlids from South America: oscar fish, green terror, flowerhorn.

This happens for two reasons – the fish is extremely interesting and it makes your tank very unusual as well as it can protect itself even from such aggressive fishes.

Gender differences: male vs female

The fish is colored more brightly than the female. However, it is difficult to tell between male and female even for an experienced breeder.


In the wild breeds in deep burrows along the river beaches. In a tank it is challenging to reproduce such conditions, moreover, it is impossible.

The fish is massively bred in Singapore, Hong Kong, Florida.

About author: Sergey Schulz

Sergey is a founder and author of He’s been fond of aquarium husbandry since his early childhood. His favorite aquariums are biotopes (Amazon River), with Echinodorus and freshwater angelfish. However, through the years he’s had experience of keeping almost all types of freshwater fish and shrimps.