Inheritance of Predorsal Black Stripe in Black Crappie

Abstract

This study presents data on inheritance of the predorsal black stripe in black crappie Pomoxis nigromaculatus. Four progeny groups, obtained by crossing fish with certain phenotypes and of known origin, were investigated. Presence of the black stripe in all fish in two progeny groups, produced by crossing fish with and without the black stripe, indicated dominance of this trait. In two F₂ progeny groups, segregations of fish with: without stripe did not differ significantly from the 3:1 Mendelian ratio. It was concluded from the data that the appearance of predorsal stripe in black crappie is under the control of a dominant mutation of one gene (St/st): fish with genotypes StSt and Stst have a stripe, while fish with genotype stst do not possess this trait. Presence or absence of the black stripe was not connected with sex of the fish. This indicates that gene St/st is located in an autosome but not in a sex chromosome. Distribution of fish with stripe in one F₂ progeny group with regard to relative width of stripe did not differ significantly from unimodal normal distribution. This indicates that allele St approaches complete dominance or is, in fact, completely dominant. Black stripe may be used as a genetic marker in experiments on induced gynogenesis and in stocking programs for distinguishing introduced fish from the native stocks.