WHITE RIVER (MOUNTAIN) SUCKER Catostomus dark! intermedius (Tanner, 1942) 



Order CYPRINIFORMES Family: CATOSTOMIDAE 



Distinguishing characteristics : Less than 35 scales anterior to the dorsal fin; fontanelle 

 closed; notch at each corner of mouth; edge of jaw inside lower lip with a hard cartila- 

 ginous sheath; head long and slender, depth about 2/3 of the length; interorbital width 

 2.1 o^ Vngth; width of mouth contained four times in length of head; papillae in 4 rows 

 on upper lip and 8-9 rows on lower lip. 



Present distribution : Remnant waters of the pluvial White River in White River Valley, 

 Nevada . § 



Former distribution : Same as present . 



Status : A matter of concern. Situation reported as improving (1972) . 



Fecundity : Unknown . 



Reasons for decline : Decline not documented but suspected as a result of irrigation 

 alterations of streamflow and establishment of exotic fishes. 



Protective measures already taken : None . 



Measures proposed : None . 



Number in captivity : None . 



Culture potential in captivity : Unknown . 



Remarks : Remnant waters still contain populations of this form . Former abundance cannot 

 be documented but the alterations of habitat and establishment of Cyprinus carpio, Lebistes 

 reticulatus and Gambusia affinis in waters occupied by Catostomus clarki intermedius 

 suggest that the latter species may not be as abundant as formerly. It can still be 

 collected with some effort in cooler springs and their outflows in White River Valley. Data 

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



References : 



La Rivers, 1. 1962. Fishes and fisheries of Nevada. Nevada State Fish and 



Game Commission, 782 p. 

 Smith, G. 1966. Distribution and evolution of the North American Catostomid 

 fishes of the subgenus Pantosteus , genus Catostomus, Univ. Mich. Mus . 

 Zool. Misc. Publ. 129, 132 p. 



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