NEVADA PUPFISH Cyprinodon nevadensis mionectes (Miller, 1948) 



Order: ATHERINIFORMES Family: CYPRINODONTIDAE 



Distinguishing characteristics : Scale and fin ray counts lower than average for the species 

 has a reduced size, a short, deep and slab-sided body with a greatly arched and rather 

 compressed predorsal profile, and a very long head and opercle. 



Present distribution : Confined to the warm springs of Ash Meadows in the southeastern 

 section of the Amargosa Desert, Nye County, Nevada. 



Former distribution : Included at least one spring in Ash Meadows , from which this 

 subspecies is now gone . 



Status : Of concern because of limited distribution and specialized habitat. 



Estimated numbers : 50 to 2,000 in each of ten springs in Ash Meadows. 



Fecundity : Unknown . 



Reasons for decline : Introduction of crayfish , black mollies (Poecilia latipinna ) , 

 mosquitofish (Gambusia affinis ) , largemouth bass (Micropterus salmoides ) , and 

 bullfrogs; ditching of spring outflows, drainage of marshes. 



Protective measures already taken : None . 



Measures proposed : Establish Jackrabbit Spring and Mexican Spring as natural area 

 withdrawals by the Bureau of Land Management. Construct barriers to upstream 

 dispersal of introduced fishes in the outflows of these springs and attempt to remove exotics 

 presently established in them. Fence the area to prevent further introductions. Establish 

 a research program that will develop information on the ecology of the species, as well 

 as maintain constant surveillance on the effectiveness of the refugia. 



Number in captivity : None . 



Breeding potential in captivity : Good . 



Remarks : Data provided by Dr. James E. Deacon, Nevada Southern University, Las Vegas. 



References : 



Miller, R. R. 1948. The cyprinodont fishes of the Death Valley system of eastern 



California and southwestern Nevada. Misc. Publ . Mus . Zool . Univ. Mich., 



68:1-155, figs. 1-5, maps 1-3, pis. 1-15. 

 Minckley, W. L. and J. E. Deason. 1968. Southwestern fishes and the enigma of 



"endangered species." Science, Vol. 159, No. 3810, p. 1424-1432. 



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