New miniature plec placed in new genus


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Brazilian scientists have described a new genus and species of miniature plec that is highly unusual in having extremely reduced dermal plates.

Almost all plecs have a series of bony plates covering almost the entire body, but the new genus and species, which Tiago Carvalho, Pablo Lehmann and Roberto Reis name Gymnotocinclus anosteos in the latest issue of the journal Neotropical Ichthyology, has these only very small bony plates covering the body, so much so that the catfish is almost naked like many other non-loricariid catfishes.

In addition to the reduced bony plates, Gymnotocinclus anosteos differs from other members of the Hypoptopomatinae (the loricariid subfamily to which it belongs) in lacking both the lateral connecting bone and bifid haemal spines on the abdominal vertebrae posterior to the first anal-fin proximal radial, having dorsally- or anteriorly-curved odontode tips on the last dermal plates on the caudal peduncle, maxillary barbel adnate to the lower lip, lateral ethmoid almost completely encapsulating the nasal organ, ventral margin of the preopercle straight and not deflected medially, pectoral girdle exposed and supporting odontodes only in a restricted lateral area near the base of the pectoral fin, and the absence of a pectoral-fin slit.

The genus is named after the extreme reduction of the body-encasing dermal plates (from the Greek gymnos, meaning naked and Otocinclus, a hypoptopomatine genus) while the species is named after the absence of the lateral connecting bone (from the Greek anosteos, meaning boneless).

Gymnotocinclus anosteos is known from the headwaters of the Tocantins River drainage in central Brazil.

For more information, see the paper: Carvalho, TP, P Lehmann A and RE Reis (2008) Gymnotocinclus anosteos, a new uniquely-plated genus and species of loricariid catfish (Teleostei: Siluriformes) from the upper rio Tocantins basin, central Brazil. Neotropical Ichthyology 6, pp. 329"338.