New genus of miniature plecs

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Brazilian ichthyologists Fernanda Martins and Francisco Langeani have described a new genus and three new species of miniature plec from the upper Paraná River drainage, central Brazil in the latest issue of the journal Neotropical Ichthyology.

The authors name the new genus Rhinolekos and describe three new species in the new genus: R. britskii, R. garavelloi and R. schaeferi, naming all of them after prominent ichthyologists (Heraldo Britski, Julio Garavello and Scott Schaefer).

Rhinolekos is distinguished from other members of the miniature plec subfamily Hypoptopmatinae by characters in the skeleton, bony plates on the head and body, muscles, the presence of an iris operculum, and the shape of the caudal peduncle.  The genus is named after the presence of a bony plate on the snout (Greek rhinos=nose and lekos=plate).

Rhinolekos britskii (above) is distinguished from congeners in having dark bands on the pectoral-, pelvic- and anal-fin rays, 31 vertebrae, and contact between the dorsal-fin bony support and the ninth vertebra.  It is further distinguished from R. garavelloi by a longer caudal peduncle, smaller thoracic length and fewer plates in the dorsal series. It further differs from R. schaeferi by the absence of premaxillary and dentary accessory teeth and having more mid-dorsal plates.

Rhinolekos garavelloi (pictured above) differs from its congeners in having a shorter caudal peduncle, larger thoracic length, and more dorsal plates.  It is further distinguished from R. britskii in lacking dark bands on the pectoral-, pelvic and anal-fin rays, having 32 vertebrae and contact between the dorsal-fin bony support and the tenth vertebra. It further differs from R. schaeferi in having more mid-dorsal and mid-ventral plates, deeper caudal peduncle, wider head and lacking premaxillary and dentary accessory teeth.

Rhinolekos schaeferi is distinguished from congeners in having premaxillary and dentary accessory teeth, a more slender caudal peduncle and fewer mid-dorsal plates.  It further differs from R. britskii in having dark bands on pectoral-, pelvic- and anal-fin rays, 32 vertebrae and contact between the dorsal-fin bony support and the tenth vertebra.  It is further distinguished from R. garavelloi in having fewer dorsal and mid-ventral plates (vs. 30-35), longer caudal peduncle, smaller thoracic length, and a narrower head.

For more information, see the paper: Martins, FO and F Langeani (2011) Rhinolekos, a new genus with three new species of Hypoptopomatinae (Siluriformes: Loricariidae) from upper rio Paraná. Neotropical Ichthyology 9, pp. 65–78.