Ecology, Breeding Habits and Young Stages of Crenichthys baileyi, a Cyprinodont Fish of Nevada

Abstract

AMONG the most interesting fishes of the isolated drainages of the arid .American west are those that constitute certain highly localized endemic genera (Hubbs and Miller, 1948 a-b). Since very little is known about their ecology and life history, a study was made of one of the species, Crenichthys baileyi (Gilbert). This fish was originally described as Cyprinodon macularius baileyi by Gilbert (1893: 233), who emphasized the lack of pelvic fins but failed to note that the teeth are bifid, rather than trifid as in Cyprinodon. Jordan and Evermann (1896: 675) recognized the species as distinct, but still retained it in Cyprinodon, not appreciating its relationship with the genus Empetrichthys (Gilbert, 1893: 233-234, pl. 5; Miller, 1948: 99-111, pls. 10-11), which is confined to the springs of Ash Meadows and Pahrump Valley, Nevada. The species baileyi was shown by Hubbs (1941: 68) and Hubbs and Miller (1941: 1-2) to be wide-spread in warm springs throughout the remnants of the Pluvial White River system, Nevada (Hubbs and Miller, 1948 b: 7-8, pls. 3 and map 2), and to be referable to the genus Crenichthys, which Hubbs (1932) had established for a newly discovered species, C. nevadae, of Railroad Valley, Nevada. On the basis of identifications by Hubbs, Crenichthys baileyi was also reported by Sumner and Sargent (1940) and by Sumner and Lanham (1942), in their studies on the adaptation of fishes to warm-spring waters. Previous attempts to culture Crenichthys in aquaria have proved unsuccessful, although desert forms of Cyprinodon have been reared, as by Cowles (1934), Miller and Miller (1942) and Miller (1948: 122-126).