Induction and evaluation of triploidy in the Australian blacklip abalone, Haliotis rubra: a preliminary study

Abstract Large batches of sibling triploid and diploid juvenile Haliotis rubra were produced to evaluate and compare their production performances. Triploidy was induced by inhibiting extrusion of the second polar body (PB2) using either 150 μM 6-dimethylaminopurine (6-DMAP) or 0.5 mg/l cytochalasin B (CB). Best guess conditions were used in which treatments were started at 25–26 min after fertilization and continued for 20 min at 17.5–18.5 °C. Triploid percentages, survival and growth were examined up to 22 weeks after settlement. Triploid percentages in day 2 larvae were 94% and 92% in 6-DMAP and CB treatments, respectively. Overall survival from eggs to competent larvae was 30.0 and 55.5% for 6-DMAP and CB treatments, respectively, compared to 64.8% for the diploids. Yields of 20 weeks post-settlement juveniles (from competent larvae) were less than 1.9% in the two triploid treatments and the diploid control. A shell length was less than 3.7 mm in all the three cases. At 22 weeks after settlement, triploid rates were 100% for 6-DMAP and 82.5% for CB treatments.