Portal de Periódicos da CAPES

Dionda mandibularis, a new cyprinid fish endemic to the Upper Rio Verde, San Luis Potosi, Mexico, with comments on related species

1977; Volume: 18; Linguagem: Inglês

10.5962/bhl.part.15552

0080-5947

Salvador Contreras Balderas, Jorge Verduzco-Martínez,

Fish biology, ecology, and behavior

Djonda mandibularis, n. sp., is described from localities in the Upper Rio Verde, State of San Luis Potosi, Mexico, on the basis of its double S-shaped intestine, longer than the standard length; pharyngeal teeth 4-4; 37 -44 lateral-line scales, and 18 -23 predorsal scales; 8 or 9 dorsal and usually 8 (7 -10) anal rays.Particularly diagnostic is the shape of the mandible, with its lower surface flat and strongly angular in respect to its rami; the lower Up surpasses the upper by a distance nearly equal to its own thickness.This species adds a new element of Nearctic affinities to the interesting endemic fauna of the Rio Verde, and to the Panuco-Tamesi system.RESUMEN.-Dionda mandibularis, n. sp., se describe como nueva de locaUdades del Alto Rio Verde, Estado de San Luis Potosi, Mexico, sobre la base de presentar un intestino en doble S, mayor que la longitud patron; dientes faringeos 4-4; 37 -44 escamas en la linea lateral y 18 -23 predorsales; 8 a 9 radios dorsales y generalmente 8 (7 -10) anales; particularmente diagnostica es la configuracion de la mandibula, cuya superficie inferior es plana, y fuertemente angulosa respecto a las rami mandibulares; el labio inferior sobresale del labio superior por una distancia aproximadamente igual a su propio grosor.Esta especie agrega un nuevo elemento endemico de afinidades nearticas, que se agrega a la pecuUar fauna de peces de la region del Rio Verde Alto, y al systema Panuco-Tamesi.The region of La Media Luna, 7 km south of the town of Rioverde, in the State of San Luis Potosi, Mexico, was explored by the authors and a group of students of the Universidad Autonoma de Nuevo Leon, in July, 1968.They obtained samples of the interesting endemic fishes of the basin, which is part of the Rio Panuco drainage.Study of these specimens revealed some novelties of Nearctic affinities, one of which, the subject of the present paper, represents a new species referred to the cyprinid genus Dionda.