''Paracetopsis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of whale catfishes found in

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Species

There are currently three recognized species in this genus: * '' Paracetopsis atahualpa''

Vari Vari () is a southern suburb of Athens and former municipality in East Attica, Greece along the Athens coast. The ancient Athenian deme of Anagyrous was situated here. Since the 2011 local government reform it is part of the municipality Vari-Vo ...

Ferraris Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello. Founded in 1939 by Enzo Ferrari (1898–1988), the company built Auto Avio Costruzioni 815, its first car in 1940, adopted its current name in 1945, and be ...

de Pinna De Pinna was a high-end clothier for men and women founded in New York City in 1885, by Alfred De Pinna (1831–1915), a Sephardic Jew born in England. They also sold menswear-inspired clothing for women that was finely tailored. The flagship sto ...

, 2005 * '' Paracetopsis bleekeri''

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Paracetopsis esmeraldas''

, 2005

Distribution

''Paracetopsis'' species are known from river drainages of the Pacific coast of

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Description

''Paracetopsis'' species can be distinguished from species of all other genera in the Cetopsinae by the combination of the possession of a

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

ine tooth patch with two or more rows of teeth and a medial gap between the contralateral components of the tooth patch. Like in other species of cetopsines, mature males have elongated distal filaments of the dorsal and pectoral fin rays and a convex (instead of straight) margin to the anal fin. The body is relatively elongate; anteriorly the body is not compressed much, but becomes progressively compressed posteriorly. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

is complete and midlateral; though unbranched in ''P. bleekeri'' and ''P. esmeraldas'', in ''P. atahualpa'' the lateral line has a few ventrally direct branches on the

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

. The dorsal profile is straight to slightly convex; the ventral profile is convex at the abdomen and straight posteriorly. The caudal peduncle depth is approximately equal to its length. The head in profile is acutely triangular overall with a bluntly rounded snout. The eyes are placed on the sides of the head and are visible from above, but not from below. The mouth is inferior and the width is about one-half the length of the head. They have three pairs of barbels, one pair of slender maxillary barbels and two pairs of mental barbels; all three pairs of barbels are approximately the same length. The

caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

is moderately to deeply forked and symmetrical with the tips of the lobes slightly rounded. The base of the

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

is comparatively long. The pelvic fins are also usually moderately long. ''P. atahualpa'' has shorter pelvic fins and is darker in colour than ''P. bleekeri''. ''P. atahualpa'' has a maxillary barbel with a distinctly dark base instead of a pale base and a distinct notch behind the head that is not present in ''P. esmeraldas''. Both ''P. atahualpa'' and ''P. esmeraldas'' have a distinct patch of pigment on the operculum not present in ''P. bleekeri''.

References

{{Taxonbar, from=Q7133848 Cetopsidae Fish of South America Fauna of Ecuador Fauna of Peru Catfish genera Taxa named by Pieter Bleeker Freshwater fish genera