Factors Affecting the Reproductive Performance of the Atlantic White Shrimp, Penaeus setiferus, in Conventional and Unisex Tank Systems

Abstract

Conventional maturation systems for open thelycum penaeid shrimp are typified by 3.5-4.5 m diameter tanks stocked at three to seven shrimp/m² at a 1:1 sex ratio. A system based on maturation in female unisex tanks and transfer to male tanks for mating offers opportunities for development of improved experimental systems, increased efficiency in commercial systems and decreased production costs. This type of unisex system was implemented in the present study, and three maturation laboratory management techniques, including ultraviolet water treatment, vinyl tank liners, and male eyestalk ablation were tested for effects on the reproductive performance of Penaeus setiferus. Little or no differences were found among tested parameters, and consistent mating and fertilized spawns were achieved in all treatments. The use of unisex culture tanks and transfer of mature females to all male tanks for mating was found to produce a level of mating similar to that in the conventional tanks. Overall, a pooled average of 4.1% of the females in the conventional system tanks and 3.9% of the females in the unisex system tanks mated each evening. UV sterilization resulted in small decreases in fertilization and hatch rates (P < 0.05), and no positive effects were discerned for any of the parameters evaluated. No differences in prevalence of shell necrosis were observed in vinyl-lined versus fiberglass tanks, although cleaning was facilitated in lined tanks. Male eyestalk ablation had no significant effects on mating or fertilization rates (P > 0.05).