The long-lived, highly energetic, and less territorial Devils Hole Pupfish (Cyprinodon diabolis) is easily identified by the lack of pelvic fins. This is besides unique body colors between sexes and the young. Females and juveniles are yellow, while males are metallic blue. The Devils Hole Pupfish only exists in the Devils Hole. It is small, showing twelve rays in the dorsal fin, seventeen in each pectoral fin, and twenty-eight in the caudal fin. The caudal fin is convex, as the scales are toothed on the outer margin. The head and eyes are large, the anal fin elongated, and the jaws have one series of teeth. Males are larger than females.