Otocinclus Catfish

To protect our animals and to ensure they get to our customers healthy, we will only ship orders with Nano Fish via UPS Next Day Air.

Long renowned as the arch nemesis of aquarium algaes, the Otocinclus Catfish (Otocinclus macrospilus) has been eradicating tanks of this nuisance for many years. Their sucker-mouths are perfectly equipped to tackle algae from all surfaces of an aquarium.

The “Otto” or “Otto cats” as they are fondly referred to, are native to South America where they reside in fast-flowing bodies of water. As such, they enjoy aquariums with stronger water flow and good aeration. They are not large fish, maxing out around 2 inches in length. Ottos are recognizable by the mottled variety of darker colors that cover them from head to tailfin. Their skin is a mix of black, gray, and brown hues. Similar to plecos, they have rows of plating running along their bodies.

Despite their relatively shy demeanor, Ottos enjoying being in groups of 6 or more as they are very sociable and and peaceful. Due to their diminutive nature, they are commonly kept with other non-aggressive fish and small invertebrates such as freshwater shrimp, snails, and crabs. Extra care should be taken when acclimating these fish, as they can be sensitive to poor water quality/parameters. 

Being primarily an algae eater, it is best to introduce your Ottos to a well-established tank which has algae and biofilm present. In the event that algae is not readily available in your aquarium, their diet can be supplemented with fresh vegetables (cucumber and zucchini are very popular choices), algae or kelp wafers, and vegetable-based flake food.

Our Tank Water Parameters

PH: 7.2 to 7.5
GH: 7 to 8
KH: 3 to 4
TDS: 180 to 250
Temp: 72 to 75