SREL Reprint #0463




Thermal Tolerance and Biochemical Polymorphism of Immature Largemouth Bass (Micropterus salmoides) Lacepede

Stephani L. Scott



Yardley et al. (1974) found biochemical variation in largemouth bass that seemed to be correlated with current and past thermal stresses on the aquatic environment caused by the operation of nuclear reactors.  One form of malate dehydrogenase (MDH-1) was found to have two alleles (Mdh-1a) and Mdh-1 b) with heterozygotes having three bands as previously reported for this species (Wheat and Whitt, 1971).  The frequency of the alleles in a reservoir with temperatures of 50 C+ in the central areas (Pond C; Mdh-1 a =0.66), a post-thermal reservoir undergoing succession at ambient temperatures (Pond B; Mdh-1 a =0.58) and a reservoir predominated by waters of nearly ambient temperatures (Par Pond; Mdh-1 a =0.44) suggested a selective advantage of Mdh-1 a over Mdh-1 b in the hot water area.  The differences in allele frequencies in the populations inhabiting these areas were significant and each population was in equilibrium as predicted by the Hardy-Weinberg equations.  The objective of this study was to determine the thermal tolerance of the three MDH genotypes in largemouth bass.


SREL Reprint #0463

Smith, M.H. and S.L. Scott. 1975. Thermal tolerance and biochemical polymorphism of immature largemouth bass (Micropterus salmoides) Lacepede. Bulletin of the Georgia Academy of Science 34:180-184.

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