Otocinclus are algae eaters that serve the purpose really well. They are easy for beginners as they do not require much care or maintenance. But to know about their requirements this beginners guide is really helpful

Otocinclus Fish – Overview

Common NameThey are commonly referred to as Otos or Dwarf Suckers.
Scientific NameThough there are many species that have a different scientific name, the common Otocinclus have the scientific name Otocinclus vittatus.
Habitat or OriginThey are native to South America in specific the rivers of Venezuela and North Argentina. Their habitat is freshwater habitat.
Average SizeThe size depends on the species. The largest of species which is Otocinclus flexilis is 2.2 inches. The smallest of the species is Otocinclus tapirape is only one inch long.
ColorationThey come in various colors. Their colors depend on the species. The common Otos have top part brown and lower part white in color. The brown strips run alongside the body. The Golden Otos are golden in color. The Zebra Otos appear like the stripes of zebra. Silver Otos are silver in color.
Life SpanTheir life span is usually 3 – 5 years provided the tank is kept clean.
DietOtos can eat algae n the tank. But this not just enough. Algae wafers can be fed. Other vegetables like lettuce, zucchini, and spinach can also be fed by chopping them into smaller pieces. They can be twice a day. But do not overfeed.
Gender IdentificationGender identification is really difficult for these fishes. The females are larger than males. But this can be seen only from above or below.
BehaviorOtos are usually bottom dwellers but they tend to stick to the surfaces of the decors which have algae on them. Once they clear up the algae on a particular surface they move to the next one. It is amusing to see their mouth trying to grip the surface. They are very active swimmers hence it is difficult to catch them with the fish net.
CompatibilityOtos are smaller fishes hence they can be compatible with other smaller fishes like Angelfish, Catfish, Danios, Cherry Barbs, Guppies, Dwarf Gourami, Zebra Loaches, Mollies, etc. It is advisable to avoid fishes that are aggressive or those which have a wide mouth so as to swallow the Otos. 
They can be in groups of 4 or more of their own kind.
Ideal Tank ConditionsSince Otos are bottom dwellers, they need a softer substrate like sand. Decors can be added and caves or rocks can be kept for the fishes to hide themselves when they are stressed. Plants can also be kept. 
They can thrive in smaller tanks like 10-gallon tank. This 10-gallon tank can accommodate 4 -6 Otos. Wider tanks are better than taller tanks if the tanks are larger in size.
Water ParametersThe temperature should be 72- 80 degree F. pH could be ^.8-7.5 which is approximately neutral. Soft water whose dH is higher than 15 is ideal.
BreedingBreeding requires special condition. The water temperature should be raised but not above 78 degree F. this increase in temperature can help in spawning. The fishes mate in such condition. The males chase the females when they are ready. The female lays eggs. The males fertilize the eggs that are on the surfaces around the tank. In a few days, the fries come out and feed on algae and bacteria around the tank. They can adapt to adult food sooner.
Common DiseasesThey can be affected by parasitic and fungal infection like ich. This is very common among the freshwater species. Color changes, spots, loss of appetite and inactivity are signs of disease. Keeping the tank clean is the best way to avoid diseases.
Approximate CostThese fishes are available at an approximate cost of $3 – $5. This usually depends on the species and age of the fishes that we purchase.
What to look when buyingLook if the fishes are not wounded around the mouth. Make sure they do not have any disease symptoms like white spots.
Species in the MarketIn the market, most all of the species of Otocinclus like macrospilus, vestitus, cocama, affinis are available.

Gallery of Otocinclus Fish


  1.  Species of Otocinclus in FishBase.
  2. Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes. 
  3.  Corydoras diphyes (Siluriformes: Callichthyidae) and Otocinclus mimulus (Siluriformes: Loricariidae), two new species of catfishes from Paraguay, a case of mimetic association. 
  4.  Otocinclus batmani, a new species of hypoptopomatine catfish (Siluriformes: Loricariidae) from Colombia and Peru. Neotropical Ichthyology
  5. Checklist dataset
  6. “The Ideal Algae Eater? The Littlest South American Suckermouth Catfishes, Genus Otocinclus.