ANALYSIS OF A DIALLEL CROSS TO ESTIMATE EFFECTS OF CROSSING ON PERFORMANCE OF RED SWAMP CRAWFISH, PROCAMBARUS-CLARKII

A complete diallel cross among three populations of red swamp crawfish , Procambarus clarkii, was used to estimate genetic effects for body s ize traits and dressout percentage. Offspring were grown in 2.4-meter diameter fiberglass pools with rice as forage. Crawfish were harvested after 150 days, sorted by sex and male maturity stage, and measured f or dressout percentage and nine body size traits. Estimates of heteros is, line, maternal, reciprocal effects and general combining ability f or traits were obtained by forming contrasts among appropriate least s quares means. Estimates were made for all animals combined and for mat ure males, immature males, and females separately. Significant (P<0.05 ) heterosis and line effects for dressout percentage indicate identifi cation of strains with higher dressout percentage may be possible. Sig nificant (P<0.05) maternal effects for body size traits of females and mature males suggest a difference in egg size, egg quality or cytopla smic inheritance among populations.