Spawning performance of domesticated penaeids in commercial hatcheries and possible impacts of eyestalk-ablation ban on postlarvae production

Sustainable development of the global shrimp industry relies on not only consistent supplies of domesticated broodstock, but also their commercially viable spawning performance. In this study we collected 13 sets of maturation data from three commercial shrimp hatcheries in Vietnam to review the reproductive performance with and without eyestalk ablation of both domesticated Penaeus vannamei and domesticated P. monodon . Our results showed that in 2024 unablated P. vannamei outperformed their ablated counterparts, producing 8.3 million nauplii/female (from 21 to 27 spawns/female) or nearly four folds higher than that of ablated females over an exploitation of 126–148 days. Spawning rate of unablated P. vannamei females was high, averaging 21.6 % nightly. A positive growth rate of 0.29 g/day was recorded for unablated P. vannamei indicating good shrimp health. Furthermore, temporal comparisons revealed a significant improvement in reproductive performance of unablated P. vannamei females (supplied by the same broodstock supplier) from 2015 to 2024 regarding spawning rate (48 % from 14.6 % to 21.6 % nightly), fecundity (37 % from 250 to 352 × 10 3 nauplii/spawn) and nauplii yield (113 % from 3.9 to 8.3 × 10 6 nauplii/female). Induced by eyestalk ablation and artificial insemination domesticated P. monodon females produced 3.3 million nauplii/female on average over 91–102 days of the exploitation period. Average fecundity ranged from 447 to 507 × 10 3 nauplii/spawn among the broodstock batches. Survival of ablated P. monodon females averaged at 58.8 ± 8.5 %. Both males and ablated females of P. monodon kept growing during the exploitation period at 0.17 ± 0.03 g and 0.14 ± 0.01 g, respectively. Unablated P. monodon females with much lower maturation rate and lower fecundity produced only 0.05 million nauplii/female or 72 folds lower than that of their ablated counterparts. Their very poor reproductive performance suggests that banning eyestalk ablation will make postlarvae production of domesticated P. monodon non-viable economically and impractical technically due to unrealistic number of broodstock to be used and substantial additional resources required. In contrast, spawning domesticated P. vannamei without eyestalk ablation should be encouraged.