CYPRINELLA-ALVAREZDELVILLARI, A NEW CYPRINID FISH FROM RIO-NAZAS OF MEXICO, WITH A KEY TO THE LEPIDA CLADE

Cyprinella alvarezdelvillari is a new species of cyprinid fish describ ed from Arroyo del Penon de Covadonga headwaters (Balneario La Concha springs to 8 km downstream), Rio Nazas, Durango, Mexico. It is a dwarf ed member of the lepida species group, differing from all others by th e following characteristics: eye diameter larger than length of snout; heavy tuberculation over most of body and fins in breeding males, esp ecially chin and center of dorsal area of pectoral hn; small spines on lips, on uppermost peduncle scale row, and over entire lachrymal; bre ast naked; a short vomer; lateral dark band as wide as eye or wider, m ost noticeable at midbody. Breeding males golden to reddish bronze on body, brighter on cheek and opercular area, with white borders on anal and paired fins; and a black overcast at peak breeding colors, caused by appearance of sparse large melanophores. Comments are presented on other members of the group, and a key is provided for their identific ation.