The Dwarf Suckermouth Catfish or Otocinclus Catfish is one of the most popular algae eating fish in the small aquarium but they do come with potential problems which are well worth knowing about before buying them.
Otos have a reputation for dying easily. This unfortunately is mainly due to the fact that most Otos in the pet store are native caught having grown up in the wild. They are captured and transported often in less than ideal conditions and can arrive in per stores with a high level of stress making them susceptible to illness. Add to this the fact that they can be sold to beginners with new tanks and they may well end up in a tank that has an insufficient supply of algae to support them.
Otos come from the soft waters of the Amazon, living in streams and rivers. They are herbivorous living on algae and plants. With algae being their principal diet it is essential that any tank that they are added to has a rich growth of algae as well as bogwood. Otos feed on the top layer of bogwood which helps with their digestion. Because of the rough surface of bogwood they are also unable to completely remove all algae. This guarantees their food supply for the future.
If there is not enough algae there diet can be supplemented with algae wafers or pellets suitable for catfish as well as blanched zucchini or lettuce. They ideally need to be kept in groups of three or more as they are sociable fish and need the company of others.
Otos are susceptible to chemicals in the water and need to be removed from a tank that is being treated with any kind of chemical as they will often die when treated alongside other fish.
Otos can live between seven and ten years given the right water conditions so don’t be put off by the bad press. They are industrial little fish that will help enormously with algae control, but remember that they always need a constant supply of algae or other food.
Nick Bynoth is fairly new to the aquarium keeping hobby. He got involved in the hobby when helping some friends who kept fish to build a hobby website. He has since gone on to start his own aquarium and create a blog about the set up process. If you found this article of interest, read more at