Scoloplax

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Scoloplax
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Superfamily: Loricarioidea
Family: Scoloplacidae
Bailey and Baskin, 1976
Genus: Scoloplax
Bailey and Baskin, 1976
Type species
Scoloplax dicra
Bailey & Baskin, 1976
Binomial name

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 family (biology) Scoloplacidae, the spiny dwarf catfishes. It includes four species, S. dicra, S. distolothrix, S. dolicholophia, and S. empousa.[1]These fish are found in fresh water in Peru, Bolivia, Brazil, and Paraguay.[2] 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.[2]

Contents

[edit] Distribution

Scoloplax is distributed in South America in Peru, Bolivia, Brazil, and Paraguay.[2] S. dicra originates 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. S. empousa lives in the Amazon and Paraguay-Paraná River basins.[1]

[edit] Description

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.[2] The greatest length reached is about 20 millimetres (0.8 in) SL.[2]

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.[3]

[edit] Ecology

Scoloplax species are fairly common among leaf litter in oxbow lakes, backwater pools, and well-vegetated streams.[3]

[edit] References

  1. ^ a b Ferraris, Carl J., Jr. (2007). "Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types" (PDF). Zootaxa 1418: 1–628. 
  2. ^ a b c d e Nelson, Joseph S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 0-471-25031-7. 
  3. ^ a b "Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes" (PDF) (1998). Copeia (3): 663–675.