Reproductive performance of the first generation Stichopus horrens broodstock

The production of cultivated sea cucumber Stichopus horrens broodstock is urgently being carried out, considering the sharp decline of natural broodstock. Therefore, natural broodstock (F0) were spawned, and their larvae were reared in a hatchery until they metamorphosed into seeds (F1). Further cultured in the earthen pond for 16 months to reach broodstock size. After determining the sex by the evisceration method, males and females were cultured in separate concrete tanks measuring 2 × 1 × 1m³ to regenerate internal organs and gonad maturation, and fed with fresh grounded Sargassum sp. and Ulva sp. at 3% biomass. Eleven months later, the F1 broodstock was divided into three groups based on body weight: small (116.22 ± 9.81 g and 109.80 ± 5.72 g), medium (134.08 ± 7.48 g and 136.10 ± 12.78 g), and large (152.56 ± 190.01 g and 170.20 ± 7.92 g) for male and female, respectively. Five pairs from each broodstock group were spawned separately in fifteen 30 L polycarbonate tanks. The F1 broodstock could produce 180,000 to 820,000 eggs per broodstock, but not significantly different (P > 0.05) among broodstock size groups. The highest egg diameter (200.92 ± 18.18 μm) and larval survival were obtained in the large broodstock size group and were significantly different (P < 0.05) from the others. The highest hatching rate (82.12 ± 4.38%) was obtained in large broodstock size, followed by medium broodstock size, and was significantly different (P < 0.05) from the small broodstock size group. Mean F1 is suitable for domesticated broodstock, especially from large broodstock size groups.