Title: Genetic Evidence for Naturally Occuring Fertile Hybrids Between Two Goby Species, Pomatoschistus minutus and P. Ioszanoi (Pisces, Gobiidae)
Abstract: Sympatric populatlons of the closely related sand goby species Pornatoschistus rninutus and P. lozanoi were examined electrophoretically.Out of a total of 33 protein loci resolved, three were completely species diagnostic and one was virtually so.In samples containing, in all, 1051 P. minutus and 604 P. lozanoi, five individuals with a hybrid genotype at all these loci were found.As well as these F, individuals, one fish of unusual genotype at these four loci was discovered.On the criterion of the distribution of the alleles at these four loci the probability that this fish is a n F, hybrid is <5 X 1 0 -~; that it is a backcross, only slightly higher.We conclude that this individual is most likely to be an F, resulting from a cross between two F, individuals.