Otocinclus

What are Otocinclus Catfish?

This genus of South American catfish consists of about 20 species so far and are often referred to as “otos” for short. Common species in the aquarium hobby include O. vittatus (common otocinclus), O. macrospilus (dwarf otocinclus), and O. cocama (zebra oto). Otocinclus typically range from 1.5–2 inches (4–5 cm), and many kinds are known for having a black horizontal line, dark grayish-brown back, and white belly. Unlike many catfish, they are diurnal (or awake during the daytime). They can usually be found grazing or resting on the ground and flat surfaces (e.g., plant leaves, hardscape, and tank walls) until they suddenly zip away to the other side of the tank.

Are otocinclus good algae eaters? These little critters love nothing more than to nibble algae off plants, glass, tank decor, and other smooth surfaces. They specialize in eating softer algae such as soft green algae and brown diatoms and tend to avoid harder types like black beard or green spot algae. They also love to eat the biofilm that grows on driftwood and other botanicals that are slowly breaking down in the aquarium.