池塘养殖斑节对虾生长、发育与性成熟

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.鱼媪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.

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

The paper studied the growth and development of sexual characters, primary sexual maturity, sexual maturity of pond-reared Penaeus monodon in relation to culture conditions in several years. The results showed that the carapace length was positively and linearly correlated to the pudendum length and thelycum width of pond-reared P. monodon. The minimal average carapace length, body length and body weight at primary sexual maturity of pond-reared males and females were 3.1 cm, 11.1 cm,20.0 g and 4.3 cm, 15.1 cm, 53.0 g, respectively. There were not different among different culture conditions. The average carapace length, body length and body weight at sexual maturity of pond-reared males and females were 3.7 cm, 13.0 cm, 37.0 g and 5.0 cm, 17.0 cm, 75.0 g, respectively. The sexual maturity was positively and linearly correlated to day age of pond-reared Penaeus monodon. The culture conditions (density, natural food) were key factors known to influence the growth, development and sexual maturity of pond-reared Penaeus monodon. The earliest time of spermatophore production of the tide pond males (120 days) was significantly earlier (P < 0.001) than the earthen pond males (150 days). The day ages of sexual maturity of male were 160 days (tidal pond) and 260 days (earthen pond), respectively. Prawns started mating at 165 days from tidal pond and at 240-280 days from earthen pond, reached full ovarian maturation and spawned as early as about 205-236 days (tidal pond) and 295-360 days (earthen pond).