Ancistrus falconensis n. sp. and A. gymnorhynchus Kner (Siluriformes: Loricariidae) from central Venezuelan Caribbean coastal streams

Abstract

A new species, Ancistrus falconensis, is described from the Hueque and Ricoa Rivers, small, isolated Caribbean drainages of northwest Falcón state, (Western Caribbean Zoogeographic Province) Venezuela and compared with A. gymnorhynchus Kner 1854 which occurs in adjacent drainages to the south. Adults of Ancistrus falconensis usually have small light spots on the abdomen in preserved specimens whereas A. gymnorhynchus almost always has the abdomen uniformly gray). They are further distinguished by the following ratios in specimens greater than 60 mm SL: mouth width/pectoral spine length (0.661–0.915 vs. 0.480–0.669, (two specimens of 88 overlap), dentary tooth cup length/ pectoral spine length (0.207–0.264 vs. 0.143–0.198), and premaxillary tooth cup length/pectoral spine length (0.146– 0.215 vs. 0.215–0.318). Falcón state is arid in the area of the type locality of A. falconensis, and water resources face increasing demands for urban, agricultural and industrial uses. Deforestation, river channelization and water diversion heavily impact most coastal streams, causing accelerating habitat loss and degradation. Thus, this new species must be considered vulnerable to extinction.