Carvalho, T.P ., Lundberg, J.G., Baskin, J.N., Friel, J.P. & Reis, R.E.

ABSTRACT

A new species of the aspredinid catfish tribe Hoplomyzontini Micromyzon is described from two specimens collected with trawl nets in two localities, at 10 and 18 m depth, in the main channel of the lower Orinoco River in Venezuela almost 40 years ago. The new species is distinguished from its only congener, Micromyzon akamai, by the: straight anterior margin of the mesethmoid; open posterior cranial fontanel; ossified first pectoral-fin radial; single tubular infraorbital bone; infraorbital sensory canal entering neurocranium via the frontal; enclosed foramen for the abductor superficialis muscle in the coracoid; higher vertebral count (33 vs. 28–32); higher anal-fin ray count (10 or 11 vs. 7–9); and some morphometric features. The holotype of the new species was scanned using High-Resolution X-ray Computed Tomography to illustrate, describe, and compare its bony skeleton to other hoplomyzontins.

Artigo completo: http://www.bioone.org/doi/10.1635/053.165.0104

Fig. 1.Micromyzon orinoco, holotype, ANSP 198335, 15.6 mm SL, Río Orinoco, deep channel upstream of Los Barrancos, ca. 183 nautical miles from sea buoy in Boca Grande navigation channel, Anzoátegui, Venezuela, 08°21′N 062°43′W. Dorsal, left side lateral and ventral views.