The description of a new species of rock-climbing catfish has led ichthyologists to believe that the common ancestor of the Loricariidae (plecs) and Astroblepidae was probably able to climb over rocks by grasping them with its mouth and pelvic fins.
The new species is named Lithogenes wahari by ichthyologists Scott Schaefer and Francisco Provenzano in a recent issue of the journal American Museum Novitates.
Lithogenes wahari, named after Ru-Wahari (the god of the creation according to the Piaroa peoples), is the third member of the genus and is distinguished from the other two Lithogenes by the absence of odontodes on the proximal portion of the ventral surface of the first pelvic-fin ray, extensive ridges on the thickened skin of the pelvic pad, lack of accessory premaxillary teeth, and anal fin with intense pigment band along the base and a diffuse spot at the midlength of the fin rays.
Lithogenes wahari is known from the Cuao River, which is part of the Orinoco River drainage in Venezuela.
It inhabits forest streams of a high gradient and with clear, swift water over an exposed bedrock substratum.
Stanford Zent, an anthropologist working in Amazonas State in Venezuela, first collected the new catfish in 1986 but it was not until after three concerted expeditions by the authors to find the fish that more were obtained in 2001.
For more information, see the paper: Schaefer, SA and F Provenzano (2008) The Lithogeninae (Siluriformes, Loricariidae): anatomy, interrelationships, and description of a new species. American Museum Novitates 3637, pp. 1"49.