For example, it has sometimes been suggested that it occurs in southern Central America, but this is an entirely separate species, Hemiancistrus aspidolepis (also known under another synonym, Hypostomus panamensis).

[12][13] The same identification issues have spread in the literature regarding the invasive catfishes in Taiwan, with H. plecostomus being one of the numerous names used to designate the species: DNA studies showed the alien fishes were actually P. pardalis and P. disjunctivus (that hybridise extensively).

[3] In captivity, however, a full-grown Hypostomus plecostomus only reaches 15 inches (38 cm) on average, which could be explained by the subpar oxygen levels in most home aquaria and other practices of bad fish husbandry.

[20] In the aquarium trade, this dark-colored, bottom-feeding, nocturnal catfish is often purchased for its ability to clean algae from fish tanks but also contributes a lot of waste to the nitrogen cycle.

[23] In September 2024, the Selangor state government in Malaysia allocated RM50,000 (approximately US$ 11,533) as an incentive to capture 50,000 kg of the fish in Langat River.

[25] They were introduced in the 1970s via the aquarium trade and has since become highly invasive to Laguna de Bay (including tributaries like the Marikina River) and the Agusan Marsh.

In 2012, Weber, Covain, and Fisch-Muller showed the type series of Carl Linnaeus was heterogenous and comprised two species: H. plecostomus (for which the authors designate a lectotype) and H. watwata.