Monday, October 3, 2011

[Ichthyology • 2010] Leptodoras marki • A new species of thorny catfish Leptodoras (Doradidae) from from Rio Fresco, Xingu Basin, Brazil

Leptodoras marki, new species
Family: Doradidae

A new species of the thorny catfish genus Leptodoras (family Doradidae) is described. The new species shares three characters with its congeners, the modified oral hood with distinct upper labial extensions, the first gill arch with enlarged accessory lamellae extending well onto medial face of gill filaments, and the pelvic fin inserted in anterior half of body. The new species is distinguished from congeners by having a large dark submarginal blotch on distal half of dorsal-fin spine and anteriormost dorsal-fin branched rays, lower labial extension of modified oral hood extending more posteriorly than upper labial extension, relatively few midlateral scutes, gas bladder moderately sized (not reduced), paired bony capsules on anteriormost vertebrae reduced to paired cup-like laminar ossifications separated by a triangular septum, pair of small, swelling-like diverticula on each side of the anterior chamber of gas bladder, a well-developed anterior nuchal plate, and nuchal foramina present. The new species was discovered from a single specimen collected in the rio Fresco, a tributary of the rio Xingu, and is described based on this and on additional material recently collected in the same area. A discussion of its placement within Leptodoras is also presented.

Birindelli, J.L.O. & Sousa, L.M. 2010. New Species of the Thorny Catfish Genus Leptodoras (Siluriformes: Doradidae) from Rio Fresco, Xingu Basin, Brazil. Copeia. 2010 (2): 292-299.: