Skip to main content

The Zebra Oto Catfish

I enjoy keeping both saltwater and freshwater fish tanks and sharing my knowledge with other aquarists.


A zebra oto (Otocinclus cocama) is one of those rare finds in the pet store. Its distinctive black body with white stripes gives it the zebra moniker while the scientific name is derived from the Peruvian Indians (Cocama-Cocamilla) in the region where they originate.

Zebra Oto Basics

While you might be tempted to buy one of these little guys, the zebra oto doesn’t do well alone. It needs to be kept in groups of three or more, but for the best results you should shoot for a group of at least six to ten. Like other Otocinclus catfish, this one needs a tank environment with several hiding places and adequate algae or supplemental food sources to maintain a small shoal. The best tank set-up for zebra oto includes several live plants and a consistent source of algae – whether it be by naturally generated means or through the addition of wafers.



A severe sensitivity to environmental changes makes this fish tricky to place in a new tank. It should be one of the last fish added to a well-established tank. It requires a standard tropical temperature 70-77F and a pH range of 6.0-7.5. Stability in both temperature and pH is paramount. Large changes in either over a short period of time will make the fish susceptible to diseases, including bloat and swim bladder disease as well as make them vulnerable to any parasites that may be in the tank.

This is by no means a beginner fish. Even advanced aquarists sometimes lose these for no discernible reason. It is recommended that you purchase these fish either directly upon arrival at the pet store or after they have been there for a week or more. This will limit the number of stresses that the new fish have to deal with.

Tank Size

Although this is primarily an algae eating bottom feeder, it has adapted several teeth to eat small live foods and occasional carcasses. At a tiny 1.7 inches, this is a great algae eater that won’t outgrow a small tank. Given the need for constant feeding, unless a 10-gallon tank is heavily planted, it might not be large enough to support a small colony. Instead, a 20-gallon or larger tank is suggested. It is important to note that this is a very active river fish and should never be kept in a tank without a lid. There isn’t a huge history of evidence for this fish jumping, but because of its natural environment, jumping is quite likely.


A zebra oto will cause no problem with other fish in your tank; it is extremely docile. In fact, the zebra oto is such a passive fish that it will actually starve before it competes for food with other bottom feeders. As long as the oto feels safe, it will feed and stay out of the paths of other fish. The best fish to keep with zebra otos are smaller tetras, danios, guppies, mollies, swordtails and platies. Cichlids and other semi aggressive to aggressive breeds should be avoided.


The zebra oto is first and foremost an algae eater. It will feast on most green algae, brown algae and diatoms. If your fish looks thin and there doesn’t seem to be a reason, it probably doesn’t have enough to eat. Although they have been seen to eat flake foods, they will not compete with other fish for it. You are better off blanching some zucchini or cucumber and placing it in the tank. Once it settles at the bottom, the otos will commence to eating. Unlike other otos, the zebra oto will also eat meaty foods like bloodworms and carnivore pellets.

The zebra oto is a beautiful fish and looks stunning in a shoal, but caring for one should not be attempted by an amateur. Only someone with years of experience and success with difficult fish should attempt to keep these. They are far more sensitive than the common Otocinclus, not to mention more expensive. If you do attempt them, make sure they are the last fish you add, and keep a close eye on them. If you can successfully raise them, you’ll find they are well worth the effort.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.


Ann1Az2 from Orange, Texas on July 27, 2014:

A pretty fish - I enjoyed your videos. You have a pretty tank and the zebra looks great! Thanks for sharing!