Allozyme Variation in a Natural Population of the Nile Crocodile

Blood samples were collected for allozyme studies from 92 Crocodylus niloticus from the Runde River in Gonarezhou National Park, southern Zimbabwe. Two (glucose phosphate isomerase and erythrocyte acid phosphatase) of 27 protein coding loci were polymorphic when examined by starch-gel electrophoresis. This amount of variability is similar to that found in another crocodilian, Alligator mississippiensis and is not unusually low as has been found in a number of large vertebrates. In a single semi-isolated population, allele frequencies at both polymorphic loci were in Hardy-Weinberg equilibrium suggesting a random mating pattern with no severe bottleneck effect in the founding of this population. Population F-statistics suggest that panmixia exists within and among the three main breeding sites studied.