Their role is better filled in the average hobbyists aquarium by invertebrates such as Caridina multidentata and various species of snails, or simply with regular maintenance with an algae scraping implement.
An example of one South American biotope type might be lots of bog-wood, a few native plants, with dark substrata and subdued lighting with floating plants, along with marbled hatchets, angels, cardinals, otos, corys and plecostomus.
A scientific study of the species found in five locations in the Laguna de Bay tributary system, including the Marikina River, revealed that the specimen of janitor fish previously reported as Hypostomus plecostomus actually belong to the genus Pterygoplichthys, family Loricariidae.