Parapimelodus

Taxobox
name = "Parapimelodus"
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
familia = Pimelodidae
genus = "Parapimelodus"
genus_authority = La Monte, 1933
binomial = "Parapimelodus nigribarbis"
binomial_authority = (Boulenger, 1889)
binomial2 = "Parapimelodus valenciennis"
binomial2_authority = (Lütken, 1874)

"Parapimelodus" is a small genus of catfishes (order Siluriformes) of the family Pimelodidae. It contains two species, "P. nigribarbis" and "P. valenciennis". [cite journal|url=http://silurus.acnatsci.org/ACSI/library/biblios/2007_Ferraris_Catfish_Checklist.pdf|title=Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types|first=Carl J., Jr.|last=Ferraris|journal=Zootaxa|volume=1418|pages=1–628|year=2007|format=PDF]

Distribution

The two species of "Parapimelodus" are isolated from each other. "P. valenciennis" is known from the Uruguay, La Plata, Paraguay, and the lower to middle Paraná Rivers. "P. nigribarbis" is restricted to the Laguna Dos Patos 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 melanophores, while paired fins are less strongly pigmented.

Ecology

Species of "Parapimelodus" have extremely long gill rakers and more than 55 gill rakers on the first branchial arch, which is related to feeding on plankton. 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.cite journal|title=Resurrection of the Neotropical Pimelodid Catfish "Parapimelodus nigribarbis" (Boulenger), with a Phylogenetic Diagnosis of the Genus "Parapimelodus" (Teleostei: Siluriformes)|first=Carlos A. S.|last=Lucena|coauthors=Malbarba, Luiz R.; Reis, Roberto E.|journal=Copeia|year=1992|issue=1|pages=138–146|doi=10.2307/1446545|volume=1992]

"P. valenciennis" has a possible greater abundance in lagoons than other catfish. "P. nigribarbis" is the most abundant species in beam trawling at the Saco de Tapes, laguna dos Patos.

References