Otocinclus catfish, also known as Oto cats, are small, peaceful fish that are popular among aquarists due to their size and their ability to clean algae from tank walls and decorations. These fish are native to South America and can be found in a variety of freshwater habitats, including rivers, streams, and flooded forests.

In terms of appearance, Oto cats are small, elongated fish that are typically less than 2 inches in length. They have a brown or green coloration with black spots or stripes, and they have a unique, sucker-like mouth that they use to attach themselves to surfaces in the tank. They have a peaceful and social behavior, and can be kept in groups of 5 or more.

When it comes to tank requirements, Oto cats are relatively easy to care for, but they do have some specific needs that should be met. They require a clean and well-maintained tank with a pH between 6.5 and 7.5. They also need plenty of hiding spots and surfaces to attach themselves to, such as live plants, rocks, and driftwood. Additionally, they are very sensitive to water pollution, so regular water changes and a good filtration system are essential for their well-being.

One important thing to consider when keeping Oto cats is their diet. They are primarily algae-eaters and require a steady supply of algae or algae-based food in order to thrive. They can be fed a variety of algae-based foods, such as blanched lettuce, spinach, or spirulina pellets, as well as dried algae wafers or tablets. It's also important to supplement their diet with high-quality protein sources, such as brine shrimp or blood worms.

In summary, Otocinclus catfish are small, peaceful fish that are popular among aquarists due to their ability to clean algae from tank walls and decorations. They are relatively easy to care for, but do have specific needs such as a clean and well-maintained tank with a pH between 6.5 and 7.5, plenty of hiding spots and surfaces, a good filtration system, and a steady supply of algae-based food.