Ancistrus

This is Nigel. He lives in our 56 gallon fish tank, along with 2 goldfish. This bristlenose pleco is about 2 inches long currently, and has a few more to grow. He has proven to be a very effective algae eater and doesn't bother our goldfish, which is nice:) He enjoys the algae that grows in the tank, as well as sheets of algae (intended for salt water fish), algae wafers, thawed blood worms, live brine shrimp, shrimp pellets, blanched greens and just about anything else we put in the tank. Lately at night he has taken to "climbing" up the filter outputs (emperor filters). I am assuming the ancistrus (bristle nose pleco) is eating the algae off of them. They are up above the water level so he makes quite a bit of splashing noise as he does this.

Popular aquarium fish because of their algae eating abilities, Ancistrus catfish can be found in many fish stores. They are often called bristlenose plecostomus or bushynose plecostomus. Bristlenose plecos (plecostomus) rarely grow past 4 or 5 inches in total length and usually mottled brown to black, sometimes shading to grey when stressed. Young sometimes have white spots on them. In my experiences with them the spots fade as they get older. Ancistrus can also be found in an albino form. As the bristlenose plecos grow their bristles start to form. They usually start around the edges of the mouth and, if male, will eventually cover the entire end of their snout. Female bristle nose plecos usually only have them around the edge of the mouth, sometimes they grow none at all. The amount of bristles also depends on species.

Bristlenose plecos (Ancistrus) eat a variety of foods but are mainly herbivorous. They eat algae, which is what has made them so popular, along with their smaller size. In captivity bristlenose plecos can be fed algae wafers, blanched zucchini and darker green letucces, blood worms, shrimp pellets, deskinned peas and a variety of other things. They should also have driftwood available as they eat a bit of it as well. The driftwood is thought to provide them with extra fiber.

While bristlenose plecos come from areas of soft water with a lower pH they adapt fine to a variety of water conditions. I know several people who keep them successfully in african cichlid tanks where the pH is 8.0 and up. Bristlenose plecos do require clean water and seem particularly sensitive to high nitrates.

From wikipedia:
Ancistrus is a genus of freshwater fish in the family Loricariidae of order Siluriformes. Fishes of this genus are commonly known as the bushynose or bristlenose plecs.
These fish are often kept by aquarists as they are dutiful algae-eaters and smaller in adult size than the common plecos usually seen in petshops. They are hardy animals, tolerant to a wide range of water conditions, breeding easily in captivity, compatible with most other freshwater fish, and come in many beautiful colors and patterns.

Links about ancistrus:
http://en.wikipedia.org/wiki/Bristlenose_pleco
http://www.planetcatfish.com/catelog/genus.php?genus_id=4#221
http://www.fishpondinfo.com/bristle.htm
http://www.aqualandpetsplus.com/Catfish,%20Plecoctomus,%20Bristlenose.htm