Amazon Otocinclus (Otocinclus cf. macrospilus)

One of the most popular aquarium algae eaters (and for good reason), the Amazon Otocinclus, Oto, or Oto Catfish is a small, schooling suckermouth cat found throughout much of South America. There are several species of Otocinclus commonly imported for the aquarium trade, but of these the larger, more robust species found in the Central Amazon (O. cf. macrospilus) is probably the hardiest and best choice for most aquariums. Safe for all planted tanks and compatible with any peaceful tankmates, the Amazon Otocinclus will feed readily on diatom and other forms of nuisance algae in the aquarium but should be supplemented regularly with sinking veggie-based foods, gel diet, and fresh vegetables like zucchini or romaine lettuce. A social species often found in huge aggregations, all Otocinclus species should be kept in groups of at least 5 but preferably 10 or more fish if space allows.