The Rhino Pleco (Pterygoplichthys scrophus) also known to tropical fish keeping enthusiasts as the Alligator Pleco or Chocolate Pleco is found in the Marañon and Ucayali River basins at Nauta, Peru.
Rhino Plecos can be identified by the number of rays they have in their dorsal fins. Most plecos, like the larger Hypostomus species, have 8 or fewer rays however, the Rhiono Pleco and all Pterygoplichtys species have more than 10.
Rhino Plecos have two horn like protrusions emanating from their large nostrils which are actually nasal flaps, and alligator like ridges along the sides of their body which give them their common name.
They can be colored black, a rich dark brown, cinnamon, or a light and dark mottled brown.
Sexing can be determined by comparing the papilla in adult specimens. Male fish have a small, thick stump that protrudes from their underside. In
female specimens, the stump is recessed or lies flat along the body. Females are also chubbier than the males.
Although Pterygoplichthys scrophus is considered an omnivore, they are excellent algae eaters and will eat all but the hardiest of plants. They will even eat floating plants when sufficient algae is not present in the aquarium.
Rhino Plecos are a shy, peaceful species that can become aggressive with other bottom dwellers if not given enough space, however, they generally make an excellent community fish and usually get along with any medium sized community tank species.
Rhino Plecos should be housed in a large densely planted tank of at least 55 gallon capacity, with a small to medium size substrate, some rocks positioned into caves for them to hide among, some bogwoodor driftwood, and some floating plants to diffuse overhead lighting.
Like most plecostomus, they need a good filtration system to remove the large amount of waste they produce. A good canister type filtration system is recommended to keep the water pristine.
There have been no successful documented breeding of Pterygoplichthys scrophus but they are believed to be cave spawners.
The Rhino Pleco is easy to feed and will readily eat a variety of foods. They are voracious algae eaters but will also eat a good quality sinking pellet, algae wafers, blanched vegetables, as well as a variety of frozen or freeze dried foods.
Rhino Plecos are available online and from specialty tropical fish shops at reasonable prices when they are 1 1/2″ in size to adults.
Minimum Tank Size: 55 gallons
Care Level: Moderate
Aquarium Hardiness: Relatively Hardy
Water Conditions: 71-83°F, GH 0-12 ° dH, pH 6.0 – 7.6
Max. Size: 11″
Color Form: Black, Brown
Compatibility: Good community tank
Origin: Marañon and Ucayali River basins, Peru
Life Span: 10 years
Aquarist Experience Level: Intermediate