Introduction to Plecos

Pleco is a name used for the catfishes of the family Loricariidae . One of the species in this family is named Hypostomus plecostomus and the name Pleco is derived from the name of this species. Today, the name Pleco is used not only for Hypostomus plecostomus but for all the members of the family Loricariidae . Plecos are also known as armored catfishes, since the longitudinal rows of scutes present on the upper part of the fish resembles old-fashion armor.

If you purchase a Common Pleco in a fish store it can be one of several species, including Suckermouth Catfish ( Hypostomus plecostomus ), Bristlenose Catfish ( Ancistrus dolichopterus ), Sailfin Catfish ( Liposarcus multiradiatus ) or Amazon sailfin catfish     ( Liposarcus pardalis ). The name Common Pleco is used for a lot of different brown-mottled Plecos that grow rather big in the aquarium. They all have similar habits and requirements, so this article is of interest even if you do not know exactly which species of pleco you keep.

The maximal lifespan of common plecos is not known, but it is believed to be around 20-30 years in captivity.

Pleco size

The fish sold under the name Common Pleco in fish stores is normally no bigger than 5-10 cm (2-4 inches) but this doesn’t mean that it will stay like that forever. Unfortunately, a lot of aquarists purchase fish without first finding out how big they can get as adults. In the case of the common pleco, you should expect your fish to eventually reach a size of 30-60 cm (1-2 feet).

Pleco habits

The common plecos are nocturnal creatures that are quite passive during the day. As long as the aquarium is lit, the pleco will use its specialized omega iris to keep the light from entering its eyes. When the lights are turned off in the evening, the omega iris will open and the fish will start searching for food.

Pleco temperament and suitable tank mates

Unlike many other plecos, the species normally sold under the name Common pleco are territorial and keeping two or more large Common plecos together is rarely it good idea. It might work out fine, but you are definitely taking a risk and you should be prepared to evacuate promptly if they fail to tolerate each other. Different individuals have different temperaments and the temperament can also change gradually as the fish ages. The risk for violence is probably lower if you combine large common plecos from different species with each other, but more research is necessary before we can say anything for sure. An interesting exception is the Bristlenose catfish ( Ancistrus dolichopterus ), a lot of aquarists have managed to keep more than one Bristlenose catfish in the same aquarium (regardless of fish size).

A lot of different fish species can be housed together with Common pleco, but fat or flat bodied fish – such as goldfish and discus – should be avoided since plecos are found of sucking on such fishes.

Aquarium for common pleco

Aquarium size

Since the species sold under the name common pleco can become so big, the fishes will eventually need big aquariums. If you purchase common pleco for your small aquarium you must therefore be prepared to eventually get a bigger aquarium or find a new home for your common pleco. Large adult specimens normally need at least 200 – 375 litres (roughly 50 – 100 gallons) since they can reach a length of 30-60 cm (roughly 1-2 feet).