Not that long ago, maybe 3 weeks ago, I was contemplating whether I should get some otocinclus, for my 10-gallon aquarium. I heard from various people that the otocinclus is a very good algae eater. Back then I had some very luscious and soft algae growing all over the rocks, artificial plants, gravel, glass, intake tube and pretty much everywhere in the tank. I decided that I would do some research on the otocinclus to give me the information I need to be able to ensure that I have a good food source, the right kind of habitat and all the right things that an otocinclus needs. I went to the Internet first for some information. I learned much. In this article you will read about lots of the things I encountered and all the ups and downs about keeping these otocinclus.
I learned that the otocinclus has many names. Those other names being the oto cat and the oto. The oto can reach a maximum of 2 inches and has a typical bottom feeder shape. They prefer a heavily planted aquarium with water that is slightly acidic to slightly alkaline and slightly soft to slightly hard water. They thrive in water with a temperature between 68-79 degrees Fahrenheit. They are at best when kept in schools of 4 or more. Caution these fish may get caught in netting. Do not attempt to pull the fish free. Either let it free itself or carefully cut away at the netting. That was just some of the basic information I learned when studying these fish. This is the information that you should be very cautious of though. Otocinclus often die within the first month of being introduced to the aquarium. Some people believe this to be due to how they are caught in the wild. Imagine yourself trying to catch a small, fast fish, in a 10 gallon planted aquarium with a few rocks and maybe a piece of bogwood. Not very easy is it? Well, imagine what the people that catch these little fish go through to catch these. The have to go through a huge pond full of plants and rocks and wood. That’s even more challenging then getting a net out and trying to scoop them out of a tank. Anyway the trick that these guys use on the otocinclus is that they use this substance {forgot what it is called} to catch them. It temporarily paralyzes the oto or slows them down for a short period of time. This is believed to make it so once they reach the store they are weak and extremely unhealthy fish. Not only that, but they have a limited diet. They are herbivorous fish that prefer to eat algae. Aquarists that keep these fish though usually cannot supply the amount of algae that the otocinclus need. The otocinclus need to be constantly grazing on algae. There are types of algae that an otocinclus cannot eat for example blue algae are not suitable for the oto cat. Also algae that is hard and crusted onto the glass or other spots are not suitable for the oto. There are foods that can be substituted for the oto. Some of these foods being algae wafers. They will also take peas, cucumber, lettuce, zucchini and plenty other green veggies. To prepare these veggies you can take them and put them in water and blanch them in the microwave for a minute or so. If you place food into the aquarium and the oto does not eat it don’t remove it right away. Wait a few days and if the oto still has not eaten it you should probably remove it. Some techniques that some aquarists use to keep the veggies in place are to use a piece of string or a rubber band and tie them down to a piece of bogwood or something. A veggie clip is also suitable for doing this. A technique I have learned is to get some rocks that are safe for aquarium use and clean them up. Then you place them in a container with water and place in an area that will get a good amount of lighting. In a few weeks algae will start to form on the surface of the rock. You can then place a few rocks in the tank and once all algae is eaten put those rocks back into the container and replace with more algae covered rocks. This will provide a never-ending supply of algae unless you stop growing the algae.
Before even purchasing these fish make sure you have really clean and good water. When purchasing the otocinclus be sure to ask the store manager what they feed to the oto cats. If they flake or stare at you with a blank face it is probably best to move onto a different store for otos. Otocinclus will not normally accept flake food or meat based foods. Be sure to examine to stock they have there and make sure they look healthy and in good condition. When you finally get some at home be sure to offer food as soon as possible. These fish are likely to have been starved in the store due to lack of food. Offer them food 3-4 times a day. These fish are likely to die off like flies during the first month of arrival. After the first month they are a hardy fish if you keep clean water and do 25% water changes once a week and are fun to own.
The otocinclus breed by lying there eggs on plant leaves. They eggs may take up to 72 hours to hatch and when they do hatch be sure to offer very fine live foods and green foods.
Oto cats that are tank raised are more likely to be healthy then those that are wild caught. As you can see these fish are very difficult to keep during the first month or so, but are very helpful at keeping the tank algae free. I never did find any at any stores near me so I did never purchase any. I hope that this has not turned you away from keeping oto cats. They are really a nice fish after the first month of keeping them. Happy Fishkeeping!