Abstract

CASTRO-AGUIRRE, José Luis; ANTUNA-MENDIOLA, Alberto; GONZALEZ-ACOSTA, Adrián Felipe  and  DE LA CRUZ-AGUERO, José. Mustelus albipinnis sp. nov. (Chondrichthyes: Carcharhiniformes: Triakidae) from off the southwestern coast of Baja California Sur, México. Hidrobiológica [online]. 2005, vol.15, n.2, pp.123-130. ISSN 0188-8897.

A new species of smoothhound shark, belonging to genus Mustelus Linck, 1790, is described on the basis of six specimens caught off bahía Magdalena, Baja California Sur, México. Mustelus albipinnis sp. nov. (suggested common name: "white-margin fin hound shark") has a combination of distinctive features, including a white margin in the dorsal, pectoral, pelvic and anal fins, a broad inter-nostril distance (3.0 to 3.4 TL %) and asymmetric pelvic fins, in form and size, in inmature females (this is the first report of this condition, for all known elasmobranch living species). It differs from its north-eastern Pacific congeners (M. californicus, M. dorsalis, M. henlei, and M. lunulatus) besides the above mentioned, by having a distinctive combination of characters as vertebral counts, arrangement pattern of buccopharyngeal denticles, palatoquadrates cartilages disposition and the lanceolate form of the dermal denticles below of first dorsal fin. This new species inhabits offshore waters deeper than 100 m, on rock and hard bottom, to the contrary of all known Mustelus species which do prefer shallow waters and soft bottoms.

Keywords : Triakidae; Mustelus albipinnis; species nov.; Baja California Sur; Mexico.