Reproductive exhaustion in shrimp ( Penaeus vannamei) reflected in larval biochemical composition, survival and growth

Penaeus vannamei larval quality in terms of biochemical composition and survival was studied throughout a spawning period. Spawns from broodstock at three different times during a commercial production period were sampled (15, 45, and 75 days after ablation). Biochemical composition of eggs, nauplii, 15-day old postlarvae (PL15), and growth and survival during culture were determined. As the days after ablation increased, a reproductive exhaustion of spawners was reflected in the energy reserves of the eggs produced. Overall larval performance during culture and survival was considerably higher in recently ablated spawners (15 days) and decreased in spawners 45 and 75 days after ablation. At PL15, a test for larval resistance to a salinity stress was applied that showed a decreased PL condition related to reproductive exhaustion of spawners: survival to stress decreased from 89% in recently ablated to 68% in larvae produced 45 days after ablation, and to 39% in larvae produced to the end of the spawning period. Nauplii condition index (NCI), calculated from nauplii triacylglycerol (TG) levels, percentage of viable nauplii, and nauplii length declined in nauplii produced with spawners sampled 45 and 75 days after ablation. This study demonstrated that reproductive exhaustion of shrimp spawners occurs and it becomes largely evident as time after ablation increases: spawner exhaustion is reflected in the quality of the larvae produced.