Morphological and biochemical systematics of chubs, Nocomis biguttatus and N. micropogon (Pisces: Cyprinidae), in southern Ontario
Examination of 17 presumptive gene loci by starch-gel electrophoresis revealed differential mobilities only at acid phosphatase-1, alcohol dehydrogenase, esterase-1, and phosphoglucomutase between Nocomis biguttatus and N. micropogon. No intraspecific variation was observed for any loci. The genetic identity (I) and genetic distance (D) were 0.874 and 0.134, respectively. The correlation of electrophoretic mobilities and nuptial tubercle pattern in sexually dimorphic males supports the present taxonomic distinction of these species and provides a simple, unambiguous means of identifying any individuals.Stepwise discriminant function analysis of a series of mensural characters was used to compare fish identified as to species by electrophoresis. At best this correctly assigned fish to their respective species in 85.7% of cases, with a probability of misclassification of 0.1335.This study suggests these two are sibling species, based on a comparison of biochemical and morphological differentiation.