Growth and feeding in juvenile triploid and diploid blacklip abalone, 'Haliotis rubra' (Leach, 1814), at two temperatures

Growth and feeding of juvenile triploid and diploid blacklip abalone 'Haliotis rubra' (Leach, 1814) were investigated at two temperatures of 17 and 21 °C over a 50-day period. There were no differences in growth between triploid and diploid abalone as measured by shell length and body weight. Both triploid and diploid abalone increased in length but not in weight at 21 °C. Condition indices were similar for triploid abalone maintained at both temperatures; however, those for diploid abalone were significantly higher at 17 °C than at 21 °C. Food intake was significantly greater yet feed conversion efficiency was significantly lower in triploid than in diploid abalone. Both the feeding variables were independent of temperature. On average, diploid abalone were able to convert 1 g of dry food ingested to 0.58 g of body weight, but triploid abalone only 0.44 g.