Heterozygote Deficiencies in a Breeding Population of Bufo americanus (Bufonidae: Anura): The Test of a Hypothesis

Abstract

Shoreline specificity producing genetic partitioning within a breeding pond has been proposed as a mechanism which could result in the heterozygote deficiencies observed in many anuran breeding populations (Guttman and Wilson, 1973; Case et al., 1975). This hypothesis was tested in Bufo americanus by three methods: 1) individual movement patterns of adult toads at a breeding pond, 2) comparison of genotypes ot toads found together in amplexus and 3) comparison of place of hatching of tadpoles and shoreline dispersal at metamorphosis. Although data concerning individual movement patterns indicated that toads may restrict their activities to particular areas of a breeding pond, assortative mating with respect to genotypes at two protein loci was not observed. Also, no correlation was found between place of hatching of tadpoles and shoreline dispersal at metamorphosis. These data do not support a hypothesis of spatial partitioning.