Reproduction of ablated and unablated Penaeus schmitti in captivity using diets consisting of fresh-frozen natural and dried formulated feeds

Abstract

Reproduction of Penaeus schmitti was achieved in a recirculating seawater system using three different diets: 100% fresh-frozen,50/50% fresh-frozen/dried and 100% dried formulated feeds. Shrimp fed the50/50% fresh-frozen/dried and 100% dried diets had significantly higher (P < 0.05) spawning rates (0.729/day) than those fed 100% fresh-frozen food (0.446/day). Ablation of one eyestalk enhanced female maturation under mixed (+245%) and fresh-frozen (+548%) diets, but did not influence spawn size nor spawn frequency. Spawn size did not decline during the 2-month study, but spawn frequency and number of matings were reduced toward the end of the period. Diet influenced all P. schmitti reproductive processes which were monitored during the study. One hundred percent dried formulated feed induced the best maturation, spawning and fecundity. Results using the mixed diet were slightly lower, but did not differ significantly (P > 0.05). The mixed and 100% fresh-frozen diets induced significantly higher (P < 0.05) molting (1.525 vs. 0.940/day) and mating (0.080 vs. 0.000/day) frequencies than the 100% dried diet. Considering the relative importance of all of these parameters, we conclude that the mixed diet led to the best results. The lunar cycle influenced molting and mating. Mating peaked during full and new moons while molting generally occurred between these periods.