Temporal variation in malate dehydrogenase loci from Nerita albicilla (L) (Gastropoda: Neritidae) at the Cape d'Aguilar Marine Reserve, Hong Kong

Four samples of Nerita albicilla were collected between 1993 and 1996 from Lobster Bay, Cape d'Aguilar, Hong Kong Island and investigated for allelic variations at gene loci sMDH-1* and sMDH-2* which have been assumed to encode supernatant malate dehydrogenase (E.C. No. 1.1.1.37) in the Neritidae. The isozymes were separated using isoelectric focusing electrophoresis. Three alleles were detected at the locus sMDH-1* and four at the locus sMDH-2*. The two gene loci were shown to be linked. Five electrophoretic patterns were detected, involving three genotypes of the locus sMDH-1* and four of the locus sMDH-2*. No significant differences in allele frequencies and heterozygosities were observed between the different years and seasons of sampling. No significant deviations from Hardy-Weinberg equilibrium were detected.