Growth and survival of post-larval abalone haliotis diversicolor supertexta (lischke) using an alternative culture method in the light and dark

Stott's Abalone Postlarvae Production System (SAPPS) was developed as an alternative method for settling larvae and raising postlarval abalone. It allows continuous hatchery production of abalone without using live food. The new system was tested in a 28-day trial, both in the dark and light, on Haliotis diversicolor superiexta. Plates were sprayed with a mixture containing commercial, artificial micro particle diet 1 or 2, and a 1% agar solution and assigned a 10-L flow-through tank, either in the dark or light. The four treatments-Diet 1-dark (D1-D), Diet 1-light (D1-L) Diet 2-dark (D2-D), and Diet 2-light (D2-L) were replicated 3 times. The chemical composition of the two diets was similar although lipids were 21.05% in diet 1 compared with 13.74% in diet 2. Final survival was not significantly different (P > 0.05) among the treatments and ranged from 14.8% to 31.4%. The variable results for larval settlement and low postlarval Survival in the first week was most likely due to unsatisfactory preconditioning of plastic plates with juvenile abalone trail mucus or weak settlement induction of this mucus. Although the light/dark factor was not significantly different (P > 0.05), abalone postlarvae fed diet type 2 (D2-D and D2-L) were significantly larger (P < 0.05) than those fed diet type 1 (D1-D and D1-L). The average growth rate per day was 43 +/- 4 mu m, 44 +/- 5 mu m. 51 +/- 4 mu m, and 53 +/- 4 mu m for D1-D D1-L. D2-D, and D2-L respectively. Diet 2 may have been more nutritionally complete than diet 1. SAPPS was used successfully in this trial to culture H. diversicolor supertexta postlarvae, regardless of light and natural food.