Otocinclus, the Wonder Cat!

The most common nuisance in a typical aquarium is the ever-abundant fiend known as algae. It can block light and stunt growth by growing on your plants. It grows on your glass, impeding the view through the window into a world that you’ve worked so hard to create. It will grow if you give it a place to live. Short of periodically scrubbing every inch of your aquarium, or not allowing a single glimmer of light into your tank, what can be done to ward off this tormentor? Meet the Otocinclus, your aquatic lawnmower friend.

The Otocinclus is a dwarf sucker-mouth catfish that only grows to be about 2 inches long. The Otocinclus is a tiny, lovable catfish that loves to eat algae from your aquarium, glass, and other decor. They are not known for eating aquatic plants. They are experts at eating soft green algae. This algae can often be difficult to see without looking very closely. It will be eaten by the otocinclus before it gets too big and out of control. The best part is that they are generally priced reasonably for what they do: usually anywhere from $1.99 to $5.99 per unit.

This little gem should be kept in peaceful tanks. Otocinclus don’t have a mean bone in their body and can be housed with fry and even baby dwarf shrimp. They are at their best when they can school with others of their own kind. They will often travel in packs when they are stressed and go foraging for food. This behavior is most often seen when they are first introduced to their tank. Once they feel comfortable, they won’t be afraid to settle in and will start schooling less frequently.

Experienced aquarists will tell you that Otocinclus are a very resilient fish. They don’t often contract common illnesses that plague other fish. Their greatest weakness isn’t getting enough to eat while being handled.

Unfortunately, Otocinclus are not spawned in aquariums very often. This means that most specimens you buy from a pet store will be wild caught. As with other wild caught sucker-mouth catfish, this makes for a perfect storm. Otocinclus can be collected by the hundreds and taken to a warehouse, where they will remain for a few more days before being shipped out. They arrive at a wholesaler where a few hundred of them are put into a bare-bottom aquarium with no decoration and poor lighting. The tank is virtually empty of algae. Algae wafers can be purchased, but the sheer amount of Otocinclus makes it difficult to properly feed them. A week or so later, they should be on their way to your local pet store. The store will place them in a nice tank and provide food. Feeding is difficult, however, as most stores stock a couple dozen of more Otocinclus in one tank. This is odd because they wouldn’t stock anywhere near that many plecostomus in the same tank.

Don’t worry – even through all that stress, Otocinclus can still thrive in your aquarium. Here are some tips that will help your new pet survive.

You should ensure that they are fed enough algae when you bring them home. After a few weeks of poor food, they will be very hungry. The best way to accomplish this is to have a quarantine tank and simply leave the light on for a week or so until you have algae growing all over the place.

Next, buy these fish the day after they come in to your pet store. This goes against conventional wisdom which says that you want to buy a fish that has been at the pet store longer to prove their longevity and lessen the shock of being transported too soon after arrival. Given that Otocinclus are typically grouped together in such abundant numbers – and are often put into tanks that can’t produce algae as fast as they can consume it – you want the stronger fish separated from the rest as soon as possible. Sometimes it is difficult to determine which fish have been around for the longest. It is important to take your Otocinclus back home, and to acclimate them in your quarantine aquarium that has been growing algae for the anticipation of their arrival. You’ll be able to reduce the amount of time they are starving since you already have a meal ready for them at home.

Otocinclus prefer peaceful community settings. Given their size and timid nature, they are easily out-competed for food. Make sure you have algae for them to eat before adding them to your aquarium and you’ll be amazed at the algae-control one little fish can provide. Give this dwarf catfish a try and it’ll surely win you over. They are my lifeline.