Reproductive performance indices based on physical characteristics of female blacklip abalone Haliotis rubra L.

摘要

Selection of abalone broodstock from the wild is often based on external appearances. The criteria used are size, color, and shape of the gonad. However, animals selected on external appearance are known to vary in egg fertilizability, hatching rates, and larval survival. The present study was instigated to develop easily useable indices, based on physical characteristics, for assessing the potential reproductive performance of female abalone. Analysis was conducted on wild-caught, artificially propagated blacklip abalone Haliotis rubra L., obtained from Australian coastal waters (142 deg 15 min; 38 deg 21 min S). Females were spawned using a combination of the desiccation and the UV irradiated methods and shell characteristics; length (SL), width(SW), height (SH), and total weight (W) of the spawners were determined. The fertilized eggs from each spawn were incubated, hatched, and larvae were reared separately in a flow-through system. The criteria used for assessing reproductive performance were fecundity, fertilizability, hatchability, and presettlement survival. The results show that fertilizability was positively correlated to hatchability and larval survival (P < 0.01). Furthermore, shell physical characteristics and weight can be used aspredictors of reproductive performance. Accordingly, a number of polynomial regressions incorporating SL, SW, SH. W, and egg characteristics to fertilizability, and SL and W to fecundity, were developed.