''Parapimelodus'' is a small

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

long-whiskered catfish The Pimelodidae, commonly known as the long-whiskered catfishes, are a family of catfishes ( order Siluriformes). Taxonomy The family Pimelodidae has undergone much revision. Currently, it contains about 30 genera and about 90 recognized and kno ...

es native to

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Species

There are currently two recognized species in this genus: * '' Parapimelodus nigribarbis'' ( Boulenger, 1889) * '' Parapimelodus valenciennis'' ( Lütken, 1874)

Distribution

The two species of ''Parapimelodus'' are isolated from each other. ''P. valenciennis'' is known from the

Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...

La Plata La Plata () is the capital city of Buenos Aires Province, Argentina. According to the , it has a population of 654,324 and its metropolitan area, the Greater La Plata, has 787,294 inhabitants. It is located 9 kilometers (6 miles) inland from th ...

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

, and the lower to middle

Paraná River The Paraná River ( es, Río Paraná, links=no , pt, Rio Paraná, gn, Ysyry Parana) is a river in south-central South America, running through Brazil, Paraguay, and Argentina for some ."Parana River". Encyclopædia Britannica. Encyclopædia Br ...

s. ''P. nigribarbis'' is restricted to the

Lagoa dos Patos Lagoa dos Patos (, , ; English: ''Ducks' Lagoon'') is the largest lagoon in Brazil and the largest coastal lagoon in South America. It is located in the state of Rio Grande do Sul, southern Brazil. It covers an area of , is long and has a maximu ...

system.

Description

The body is compressed and becomes strongly compressed at the tail. The head is slightly depressed and the mouth is slightly inferior, with the upper jaw longer than the lower jaw. There is one pair of maxillary barbels and two mental. The dorsal and pectoral fin spines are strong and pungent. These fish have a silvery-grey dorsal surface and a whitish or slightly yellowish ventral surface. The barbels are usually dark. Unpaired fins are usually strongly pigmented with

melanophore Chromatophores are cells that produce color, of which many types are pigment-containing cells, or groups of cells, found in a wide range of animals including amphibians, fish, reptiles, crustaceans and cephalopods. Mammals and birds, in cont ...

s, while paired fins are less strongly pigmented.

Ecology

Species of ''Parapimelodus'' have extremely long

gill raker Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the ...

s and more than 55

s on the first branchial arch, which is related to feeding on

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

. They also have very large eyes on the sides of the head that can be seen both from above and below, which is related to independence from the bottom in locomotion and feeding; though a common trait in many other catfish, it is rare in Pimelodids. ''P. valenciennis'' has a possible greater abundance in lagoons than other catfish. ''P. nigribarbis'' is the most abundant species in

beam trawling Bottom trawling is trawling (towing a trawl, which is a fishing net) along the seafloor. It is also referred to as "dragging". The scientific community divides bottom trawling into benthic trawling and Demersal zone, demersal trawling. Benthic tra ...

at the Saco de Tapes, Lagoa dos Patos.

References

{{Taxonbar, from=Q7135678 Pimelodidae Fish of South America Catfish genera Freshwater fish genera