Otocinclus Catfish 3.5cm

Otocinclus Catfish

The otocinclus more commonly known as the Oto is arguably one of the most in-demand and popular dwarf, clean-up crew species in the entire aquarium hobby. These fish only reach around 5 cm and are actually quite closely related to armoured catfish such as plecos which makes them a fantastic algae eater species for planted aquariums making them perfect to add into smaller aquariums just as an element of allure or to try out as a breeding experiment. 

Otocinclus catfish are quite small, slender-bodied fish. They also tend to be quite shy and at times will seem completely invisible in the home aquarium once they settle in. Oto’s have a very natural darker colour palette with a black, blotchy patterning on the upper half of the body which is split by a jet-black lateral line. The belly of the ottocinclus is a creamy white colour with hints of pink which is especially visible when these fish are up against the glass. The spade-shaped face with large eyes gives the otocinclus a comical, adorable look which may quite possibly be the reason why they are so popular in the aquarium trade.  The otocinclus is a naturally occurring species from South America that prefers softer water with a PH range of 6.0-7.0 and a temperature range of 24-28 degrees. 

Trying to find the males and females in this species is very challenging as males and females show no distinguishing factors. These fish are also quite difficult to breed however it has been noted that their spawning process is similar to corydoras. The best method to breed these fish is to put a group of 5-6 individuals into a well-planted tank and let them spawn. 

Tank Recommendations for your Otocinclus Catfish

Otocinclus catfish is a species that only gets to 5 cm and has a very thin profile. The ideal aquarium for a group of these fish would be around 40 litres and it can be an incredibly simple and cheap system to run. These fish will be perfectly fine in a tank with an abundance of driftwood, plants, and botanicals. The aquarium can be filtered through some basic sponge filters with minimal lighting, they will however also love a densely planted system with no problems at all. This species is mostly active when lights are turned off.

Suitable Tank Buddies

The Otocinclus catfish is extremely peaceful no aggression showed to other fish or themselves at all. These reclusive species will get along with a wide range of smaller, peaceful community fish.

Usually Compatible

Tetras, gouramis, corydoras, angelfish, barbs and dwarf cichlids such as rams.

Sometime Compatible

Oto’s can be easily outcompeted especially when kept with larger fish so it is best to avoid species like Acara, severum, geophagus, and similar species. 

Rarely Compatible 

Large aggressive species such as African cichlids, Oscars, and Jaguar cichlids will absolutely predate on the otocinclus

Feeding your Otocinclus Catfish 

Otocinlcus will easily take to a wide range of food and is arguably one of the easiest fish to feed. They are regarded as ‘wood eaters’ meaning they can easily sustain themselves eating aquarium driftwood. The best type of wood is Malaysian bog wood as this is a softer type and breaks down fairly easily. Do keep in mind that Otos feeding exclusively on wood can lead to a lot of wood dust floating around in the water so some added mechanical filtration may be required. Aside from this they will eat algae and decaying plant matter but will also eat sinking aquarium foods like sinking pleco wafers. This can be supplemented with blanched veggies like zucchini and pumpkin.