Reproductive performance of reciprocally crossed wild-caught and tank-reared Penaeus monodon broodstock

Abstract

The reproductive performance of reciprocally crossed wild-caught (W) and domesticated lines (L1 and L2) of Penaeus monodon broodstock was assessed over two moult periods under standardised conditions. Significant variations in the reproductive performance of the broodstock from the three sources (W, L1 and L2) were found. Reproductive performance was more dependent on the source of the female broodstock than the male broodstock. W females matured and spawned more rapidly after ablation and more often than L1 and L2 females. The percentage of W females spawning (86.8%) was significantly greater than that for both L1 (38.9%) and L2 females (23.7%). W females had significantly more spawnings (1.99 spawnings female − 1) than the L1 (0. 62 spawnings female − 1) and L2 females (0.37 spawnings female − 1), and spawned within a shorter period after ablation (9.2 days compared with 15.3 days for the L1 and 18.7 days for the L2 females). There was no difference in the numbers of eggs per spawning, percentage of spawnings that hatched, hatch rates and protozoeal metamorphosis rates produced from the W and the L1 tank-reared females. However, the L2 females had significantly lower numbers of eggs per spawning, percentage of spawnings that hatched and protozoeal metamorphosis rates per spawning than the W and L1 females. The lower performance of the L2 stocks, compared with the L1 stocks, demonstrates the variability in reproductive performance that can exist between different domesticated stocks. Our results suggest that the largest improvements in the reproductive output of these tank-reared P. monodon stocks will likely be found through improvements in the quality of the female broodstock.