Scoloplax

Taxobox
name = "Scoloplax"


image_width = 240px
regnum = Animalia
phylum = Chordata
classis = Actinopterygii
ordo = Siluriformes
superfamilia = Loricarioidea
familia = Scoloplacidae
familia_authority = Bailey and Baskin, 1976
genus = "Scoloplax"
genus_authority = Bailey and Baskin, 1976
type_species = "Scoloplax dicra"
type_species_authority = Bailey & Baskin, 1976
subdivision_ranks = Binomial name
subdivision =
"Scoloplax baskini"
Rocha, Oliveira & Py-Daniel, 2008
"Scoloplax dicra"
Bailey & Baskin, 1976
"Scoloplax distolothrix"
Schaefer, Weitzman & Britski, 1989
"Scoloplax dolicholophia"
Schaefer, Weitzman & Britski, 1989
"Scoloplax empousa"
Schaefer, Weitzman & Britski, 1989

"Scoloplax" is the only genus in the catfish (order Siluriformes) family Scoloplacidae, the spiny dwarf catfishes. It includes five species, "S. baskini", "S. dicra", "S. distolothrix", "S. dolicholophia", and "S. empousa".cite journal|journal=Neotropical Ichthyology|volume=6|issue=3|pages=323-328|year=2008|title="Scoloplax baskini": a new spiny dwarf catfish from rio Aripuanã, Amazonas, Brazil (Loricarioidei: Scoloplacidae)|first=Marcelo Salles|last=Rocha|coauthors=Oliveira, Renildo Ribeiro; Py-Daniel, Lúcia H. Rapp] 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] Scoloplacidae is the second-most recent family of catfish to be "discovered"; the first species was not described until 1976. The most recent family is Lacantuniidae, described in 2005.

Distribution

"Scoloplax" is distributed in South America in Peru, Bolivia, Brazil, and Paraguay.cite book|title=Fishes of the World|last=Nelson|first=Joseph S.|publisher=John Wiley & Sons, Inc|year=2006|isbn=0-471-25031-7] "S. baskini" is from the small tributaries of rio Aripuanã, rio Madeira drainage, Amazonas State, Brazil. "S. dicra" has the largest distribution inthe Amazon basin, originating from the Amazon and Paraguay River basins. "S. distolothrix" inhabits the Tocantins-Araguaia, Xingu, and Paraguay River basins. "S. dolicholophia" is known from the Rio Negro basin in Brazil as well as the Lake Amanã. "S. empousa" lives in the Amazon and Paraguay-Paraná River basins.

Description

Species of "Scoloplax" are readily distinguishable from other catfishes by the presence of a conspicuous shield-shaped rostral plate bearing numerous large and recurved odontodes. These fish have three rows of odontode-bearing plates, two bi-lateral series and one mid-ventral series. There is also a rostral plate with many recurved odootodes. The adipose fin is absent. The greatest length reached is about 20 millimetres (0.8 in) SL.

"Scoloplax" species have a modified stomach that is enlarged, thin-walled, and clear. The esophagus enters the stomach along the dorsal side just posterior to the anterior margin of the stomach; the intestine exits the stomach ventrally. A small patch of muscular tissue represents the digestive portion of the stomach was located from the entrance of the esophagus to where the intestine exits. This modified stomach may be for buoyancy control or for breathing air.cite journal|url=http://www.auburn.edu/academic/science_math/res_area/loricariid/fish_key/Air.pdf|title=Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes|journal=Copeia|year=1998|issue=3|pages=663–675|format=PDF]

Ecology

"Scoloplax" species are fairly common among leaf litter in clear and blackwater habitats including oxbow lakes, backwater pools, and well-vegetated streams.

References