Common Pleco

Hypostomus plecostomus

The common pleco label is used loosely in the aquarium trade, but Hypostomus plecostomus is an armored suckermouth catfish from tropical South America. Related Pterygoplichthys species are often sold under the same name, which is why size, pattern, and origin can be confusing. These catfish have bony plates, a rasping mouth, strong pectoral fins, and a mostly nocturnal habit of grazing surfaces for algae, biofilm, wood fibers, and invertebrate bits. A small juvenile on a shop tank wall can grow into a powerful fish well over 30 centimeters, and some common trade plecos get much larger.

Keeping a common pleco responsibly usually means planning for a large aquarium or warm pond, heavy filtration, hiding places, and driftwood. It should be fed sinking catfish foods, vegetables, and occasional protein rather than left to survive on algae. The species produces a lot of waste and may uproot plants or outcompete quieter bottom fish as it matures. Releases are harmful and often illegal; plecos have established invasive populations in warm waterways where they burrow, compete with native species, and are hard to remove.