Herbivorous Vacuum

Hypostomus plecostomus is famous for its ability to keep the aquarium sparkling clean

by Mike McEwan

The Plecostomus Catfish, Hypostomus plecostomus, is a long time aquarium favorite. The main attraction of this fish is its ability to keep the aquarium free of algae. It accomplishes this by "sucking" at the aquarium glass or decorations with its strong, under-turned mouth.

This fish is often known in the hobby as the Pleco, or Pl*co. The story behind the irregular spelling of "pl*co" is that if you spell it correctly your pleco will soon die.

The fish has an elongated, dark brown body with a large head. The belly is flat and lacks the bony plates that occur all over the rest of the fish's body. The eyes are small and set high on the head.

Tank Setup

The aquarium should be well-stocked with plants and driftwood. When they're not busy grazing on algae, Plecos like to rest on driftwood pieces or in caves. This is not an active fish and thus the aquarium need not be the usual size for a fish that grows up to 18 inches in length, though the largest tank possible is appreciated. There have been stories of Plecos growing to 15" in aquariums as small as 15 gallons. Provide a strong water current through the use of a powerhead or similar device.


Plecos should not have to rely on naturally growing algae alone as their only diet. As they mature they lose their algae eating tendencies somewhat and must be fed a basic diet of sinking herbivorous foods. Lettuce or zucchini strapped to a rock with a rubber band makes a great snack for your Pleco. Dried algae tablets can also be purchased and make a great daily food. Plecos will generally leave plants alone providing they get enough vegetable matter in the diet.

Water Chemistry

Hypostomus plecostomus is a very hardy species that will adapt to most aquarium conditions. Avoid keeping the fish in extreme pH levels or temperatures and it will usually thrive.


Due to the adult size of these catfish, most successful breedings have occured in ponds with steep clay or mud banks. They dig tunnels close to the water level and the males guard the eggs until they hatch.

Hypostomus Plecostomus

Common Name(s):
Plecostomus; Pleco; Sucker Mouth
South American rivers
Max Size:
74-82 F.
Tank Size:
45 Gallons