池塘养殖斑节对虾的生长、发育与性成熟

The growth,development and sexual maturity of pond-reared Penaeus monodon

为了解不同养殖条件下斑节对虾的生长、外生殖器发育、性腺发育及性成熟之间的关系,对其养殖进行跟踪调查研究。结果显示:①斑节对虾雌雄外生殖器官发育和头胸甲长呈线性关系;②不同养殖环境条件下,斑节对虾性成熟生物学最小型个体无显著差异。雄性精荚出现的生物学最小型个体为头胸甲长3.1 cm,体长11.1 cm,体质量20.0 g;雄性性成熟个体的头胸甲长3.7 cm,体长13.0 cm,体质量37.0 g。池养雌性斑节对虾的性成熟生物学最小型个体以纳精囊的发育完全(可与雄虾交配)为标志,其最小性成熟个体的头胸甲长4.3 cm、体长15.1 cm、体质量53.0 g,雌性性成熟个体为头胸甲长5.0 cm,体长17.0 cm,体质量75.0 g以上;③池塘养殖斑节对虾性成熟与日龄和养殖环境相关。鱼塭雄虾精荚出现的最早时间为日龄120 d前后,其性成熟日龄约为160 d;池塘养殖雄虾精荚出现的最早时间为日龄150 d前后,其性成熟日龄约为260 d。鱼塭雌虾最早交配发生在日龄165 d前后,性成熟日龄205～236 d,池养雌虾最早交配发生在日龄240～280 d,性成熟日龄295～360 d以上。

In attempt to understand the effects of rearing condition on the growth and development of the sexual characters, primary sexual maturity, and sexual maturity of pond-reared Penaeus monodon, a continuous investigation was conducted. The results indicated that the development of the external genitalia in P. monodon was linearly correlated to the carapace length of P. monodon. The minimal means of carapace length,body length and body weight at primary sexual maturity of pond-reared P. monodon were 3.1 cm, 11.1 cm, and 20.0 g （males） or 4.3 cm, 15.1 cm, and 53.0 g （ females）, respectively, and these values were not significantly affected by the rearing conditions （P and body weight at sexual maturity of pond-reared P. 〉 0. 001 ）. The average carapace length, body length monodon were 3.7 cm, 13.0 cm, and 37.0 g （males） and 5.0 cm, 17.0 cm,and 75.0 g（females） ,respectively. The sexual maturity was linearly correlated to the age of pond-reared P. monodon. The results indicated that the rearing conditions （ e. g. density, natural food） were the key factors affecting the growth, development and sexual maturity of pond-reared P. monodon. The minimal age of P. monodon appearing spermatophore werel20 days when cultured in the tide pond, which was significantly earlier（ P 〈 0. 001 ）than those cultured in the earthen pond （ 150 days）. The ages of sexual maturity in males were 160 days （tidal pond）and 260 days （earthen pond）, respectively. Prawns started mating at 165 days in the tidal pond and at 240-280 days in the earthen pond, and the sexual maturity and spawning event occurred as early as about 205 - 236 days（tidal pond） or 295 - 360 days（earthen pond）.