Cyprinodon julimes

Description

The Julimes pupfish (Cyprinodon julimes) (Spanish: Cachorrito de Julimes), is a killifish belonging to the family Cyprinodontidae (pupfish) of ray-finned fish, endemic to "El Pandeño" hot spring in Julimes, Chihuahua, Mexico. The pupfish is known as the "hottest fish in the world" due to its adaptation to life in a hot spring that reaches temperatures as high as 114 °F (46 °C). The species was taxonomically described in 2009 as similar to Cyprinodon eximius, but it has a bigger head, nearly one-third of its Standard Length. Its body is deep, the dorsal and ventral profile is convex and the lower jaw exceeds the premaxilla. The dorsal fin is placed forward with respect to the pelvic fin. Females and young have reticulate patterns of dark and light silver-brownish bands of varying lengths and thickness over the flanks, as well as a conspicuous black spot or ocellus on the distal edge of the dorsal fin. Dominant males are bluish-green in color and show a black bar along the distal edge of the caudal fin. Holotype.- UANL 18721 Collected by Ma.de Lourdes Lozano Vilano, Mauricio De la Maza Benignos, Ma. Elena García Ramírez, and the WWF group. February 25, 2007. Mature male 31.8 mm SL Paratypes.- UANL 18721 (39 specimens); TNHC39729 (2 specimens); USNM 391634 (2 specimens); UMMZ 248729 (2 specimens). Same data as holotype.