Comparisons of Triploid and Diploid White Crappies

Abstract

I produced triploid white crappies Pomoxis annularis in the laboratory by subjecting stripped eggs to 5°C for 90 min. This treatment produced triploids on three out of seven attempts, yielding 92%, 93%, and 100% triploids. I compared several hematological characteristics of adult triploid and diploid white crappies. Triploids had significantly lower concentrations of circulating red blood cells and hemoglobin than diploids but their red blood cells had significantly greater volumes and hemoglobin contents. Diploids had significantly higher gonadosomatic indices. Diploids and triploids did not differ significantly in heart weight as a percentage of body weight or in standard metabolic rate, active metabolic rate, or critical swimming speeds. Despite the hematological differences, nonreproductive triploid white crappie adults appear to be as fit for survival as normal diploid fish.