Stenorynchoacrum, Huang, Yanfei, Yang, Junxing & Chen, Xiaoyong, 2014

Huang, Yanfei, Yang, Junxing & Chen, Xiaoyong, 2014, Stenorynchoacrum xijiangensis, a new genus and a new species of Labeoninae fish from Guangxi, China (Teleostei: Cyprinidae), Zootaxa 3793 (3), pp. 379-386 : 381

Stenorynchoacrum new genus

Type species: Stenorynchoacrum xijiangensis new species

Diagnosis. Stenorynchoacrum can be distinguished from existing genera of Labeoninae by the following characters. Middle part of rostral cap undeveloped, narrow, only covering the base of the upper jaw, both sides of rostral cap well developed and extending upward, rostral cap connected the lower lip, both lateral part of which free, as the result of a long postlabial groove separating the posterior margin of lateral part of lower lip and the isthmus, the median part of lower lip protrudes to form a round fleshy pad, whose posterior margin continuous with the mental region, no crescentic fold surrounding the fleshy pad ( Fig. 2 ).

The genus possesses some additional characters: the ventral margin of rostral cap unfringed, upper lip regresses to form a row of thin, tiny lobes adnated to upper jaw, the posterior margin of lower jaw connected the anterior part of lower lip, lower lip well developed, variable papillae scattered on rostral cap and lower lip, the anterior margin of upper and lower jaws born flexible, cornified sheath, two pairs of barbels, three rows of pharyngeal teeth, and eight branched dorsal-fin rays.

Etymology. Sten from stenos Greek, means narrow; ryncho from rhynchos, Greek, means snout; acr, Greek, means the extremities of the body (snout, ears or trotters), so rynchoacrum means ventral margin of rostral cap. Stenorynchoacrum alludes to the narrow and undeveloped rostral cap of this genus.

Figures

FIGURE 2. Diagrammatic of the oromandibular structures in Stenorynchoacrum. Rfp = round fleshy pad of the midian part of lower lip; lj = lower jaw; lpll = lateral part of lower lip; mb = maxillary barbel; pg = postlabial groove; rb = rostral barbel; rc = rostral cap; u j = upper jaw.