A new species of Hemibrycon (Characiformes: Characidae), a freshwater fish from the Sierra Nevada of Santa Marta, Caribbean drainage, Colombia

Abstract

Hemibrycon is a group of freshwater characid fish species first recognized by Günther (1864) as a subgenus of Tetragonopterus, and now included in the subfamily Stevardiinae. There are 21 speciesrecorded from the rivers of Colombia, but only one species, H.santamartae, has been reported previously in drainages of the Sierra Nevada de Santa Marta. Hemibrycon sierraensis n. sp. is described fromthe Río Gaira, Caribbean coastal drainage. It is distinguished from all congeners by having in life a bright red adipose fin (vs. hyaline or transparent)that turns dark brown in specimens preserved in alcohol. It differs from Hemibrycon beni, H. boquiae, H. brevispini, H. colombianus, H. mikrostiktos, H. metae, H. microformaa, H. palomae and H. rafaelense in having a vertically elongate humeral spot that extends 3-4 longitudinal scale series below the lateral line. It differs from H. divisorensis, H. pautensis and H. santamartae by having the last dorsal-fin ray unbranched; and from H. pautensis by the number of scale series between the lateralline and the pelvic-fin insertions. It differs from H. divisorensis in the number of unbranched anal-fin rays, and the number of teeth on the dentary and maxilla. It differs from H. santamartae in the number of supraneurals, caudal peduncle depth, head length and orbital diameter.