• Care Level:    Easy
• Temperament:    Peaceful
• Color Form:    Various, most have a brown stripe down their body
• Lifespan:    3-5 years
• Size:    1-2 inches
• Diet:    Herbivore
• Family:    Loricariidae
• Minimum Tank Size:    10 gallons
• Tank Set-Up:    Freshwater- sandy substrate with caves
• Compatibility:    Peaceful community aquariums

Otocinclus are best known as algae eaters.

These fish are some of the best algae eaters around. It’s their natural food which makes them very easy to feed. They’re easy to look after too, so are great for beginners.

They’re peaceful creatures and can be put in a variety of freshwater community aquariums.

These catfish are great for small 10 gallon aquariums, because adults rarely exceed 2 inches. The smallest species (Otocinclus tapirape) only grows to be an inch long. The largest species is Otocinclus flexilis, which reaches 2.2 inches. Their body is a simple cylindrical shape which narrows towards the head and caudal fin. On the head is a strong mouth which is used to latch onto surfaces.

Those in the family Loricariidae are different to a lot of other catfish groups because of the rows of armor plating across their body. This helps to protect them from boisterous fish and coarse substrates. They have a limited ability to breathe air. A duct between the esophagus and stomach forms a hollow area which lets them breath.

Habitat and Tank Conditions

This group is mostly found in small streams or shallow rivers across South America. Here they attach themselves to the substrate or rocks in the search of algae.

The warm waters are slow-moving but well-oxygenated, pH is generally neutral. Below the water is a soft, sandy substrate. Perched on the substrate are pieces of debris like rocks, wood and anything else being moved with the water.

Some plants are around, but not a lot of them. They have access to plenty of light and it penetrates through the shallow waters.

Lots of popular aquarium fish come from the rivers of South America so an Otocinclus setup is very similar to other freshwater species.

Otocinclus Tank Mates

Otos are small and peaceful so won’t be an issue for any of your other fish – this means there are lots of possible tank mates.

Their small size makes them an easy target though, so large or aggressive fish need to be avoided. This means that a lot of cichlids aren’t a good pick. An Oscar could hunt down and kill an Otocinclus with ease. A general rule is to stay away from species with an aggressive reputation or a mouth big enough to eat an Oto whole.

This still leaves plenty of species to choose from. Some popular choices include Angelfish, Cherry Barbs, Corydoras Catfish, Danios, Dwarf Gourami, Guppies, Harlequin Rasbora, Mollies, Tetras, and Zebra Loaches.

You also have the option of keeping invertebrates. Shrimps and snails are popular tank mates because of their different appearances and behaviors.