while the Black molly is a hybrid based on Poecilia sphenops. Molly jaws can protrude forwards to make a sort of scraping tool ideal for rasping algae from plants and rocks. While omnivorous in the ...

Mollies (Poecilia sphenops/P. latipinna/P. velifera) are similarly suitable, if slightly larger, candidates. Also consider algae-eating cyprinids. These include Siamese algae eaters (Crossocheilus spp ...