Pseudacanthicus is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

es (order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Siluriformes) of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Loricariidae

Loricariidae

Loricariidae is the largest family of catfish , with almost 700 species and new species being described each year. Loricariids originate from fresh water habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are noted for the bony plates covering their bodies and...

. It includes five formally described species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

, P. fordii, P. histrix, P. leopardus, P. serratus, and P. spinosus. There are also several undescribed species from Peru to Brazil.

Distribution

Pseudacanthicus is distributed in the Orinoco

Orinoco

The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...

, the Guyanas

Guyanas

Guyana is a country in South America.Guyana, Guayana, or Guiana may also refer to:*Guayana Esequiba, the territory of Guyana claimed by Venezuela*Guayana Region, an administrative region of Venezuela...

, the Rio Negro, and the lower Amazonian

Amazon River

The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...

 tributaries. P. fordii originates from the coastal drainages of Suriname

Suriname

Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...

. P. histrix inhabits the Negro and lower Amazon River basins in Brazil. P. leopardus is known from the Rupununi River basin in Guyana

Guyana

Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...

. P. serratus lives in coastal drainages of the Guianas. P. spinosus is from the Amazon River basin in Brazil.

Description

Species of Pseudacanthicus are large, spiny loricariids with a diverse range of colour patterns. Colour is from light to dark gray, often with black spots. The fins and body may have red sections or a red wash. Colouration varies between rivers and can also change throughout the lifetime of a single individual. The abdomen is covered in small plates in adults. The caudal fin is forked, but without filaments. The jaws are short, forming an acute angle at their union; the teeth are few and stout. The adipose fin is present.

P. leopardus grows to a modest size of about 40 centimetre

Centimetre

A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...

s (14 in

Inch

An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...

) TL

Fish measurement

Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

. P. fordii, P. spinosus, and P. serratus grow larger to about 23 cm (9 in) TL, 26 cm (10 in) SL

Fish measurement

Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...

, and 32 cm (13 in) TL, respectively. P. histrix is reported to grow as large as 90 cm (35 in) TL.

P. histrix has incredibly elongated odontode

Odontode

Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They comprise a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to that of teeth. They generally do not have the same...

s that form a brush on the anterior margin of the pectoral fin spine in breeding males; however, sexual dimorphism

Sexual dimorphism

Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

 has not been reported for the other species.

P. serratus is known to scientists from only a few specimens. According to Boni

Boni

-Places:* Bone state, vassal state of the government of Celebes, Dutch East Indies* Boni, Haire, a town in Mali* Boni, Korarou, a town in Mali* Boni MRT Station, a train station in Manila, Philippines-Other:* Boni , a 2009 Telugu film...

 fishermen in Guiana, this fish lives in the deep and rocky zones of the main riverbed. Despite its size, it is not consumed as food by native populations since it has a reputation for being dirty and sticky.

In the aquarium

Pseudacanthicus species may be kept in the aquarium

Aquarium

An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...

. P. leopardus is a large attractive fish known in the aquarium hobby as the leopard cactus pleco. It is a large fish that essentially feeds on dead meat. It is territorial and care should be taken when maintaining it with other large, nocturnal fish.