SREL Reprint #2335

Phosphogluconate dehydrogenase polymorphism and salinity in the White Sands pupfish

Craig A. Stockwell1 and Margaret Mulvey2

1Department of Zoology, Stevens Hall, North Dakota State University, Fargo, North Dakota 58105-5517
2Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802

Abstract: The phosphogluconate dehydrogenase (Pgdh) locus is the only polymorphic allozyme locus observed among 37 loci examined in all four populations of a New Mexico state Endangered species, the White Sands pupfish (Cyprinodon tularosa). We report evidence suggesting that this polymorphism may be associated with salinity. Salinity levels vary widely within and between habitats occupied by White Sands pupfish. The frequency of the Pgdh100 allozyme was correlated with salinity but not with temperature. Frequency of Pgdh100  differed between low (3.76 parts per thousand (ppt)) and high (9.23 ppt) salinity sites at Malpais Spring despite no obvious barriers to fish movement. Frequencies of Pgdh100  in two introduced populations differed from that of the presumptive founding stock and correlated with salinity in the current habitats.

Keywords: Cyprinodon tularosa, Pgdh, phosphogluconate dehydrogenase, salinity, selection, translocation, White Sands pupfish

SREL Reprint #2335

Stockwell, C.A. and M. Mulvey. 1998. Phosphogluconate dehydrogenase polymorphism and salinity in the White Sands pupfish. Evolution 52:1856-1860.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).