低龄中华鲟外科手术性别鉴定技术

Surgical techniques of sex determination in young Acipenser sinensis

取 5 1尾人工养殖 1.5～ 5 .6年龄、体重 2 .6～ 35 .5kg的中华鲟 (Acipensersinensis) ,通过腹腔外科手术检查性腺并取得性腺组织材料。 5～ 5 .6年龄 (体重 18～ 35 .5kg)的中华鲟性腺都能通过肉眼分辩雌雄 ,是进行性别鉴定的较佳时期。手术时 ,水温 14 .3～ 30℃、切口位于腹中线或偏离腹中线 1～ 4cm、切口长 4～ 5 .5cm(体重 2 .6～ 9.7kg)或 3.8～ 7.5cm(13.5～ 35 .5kg)、切口采用医用丝线行交叉缝合或一针一结缝合、出池后的全程操作时间 2 0～ 30min ,可较圆满完成性腺检查和性腺组织取材 ,94 .1% (4 8/5 1)的受试鱼存活 ,伤口在 15～ 4 0d天愈合 ,缝合线自行消失。水温高、切口短。

Chinese sturgeon, Acipenser sinensis, is a large anadromous fish without apparent sexual dimorphism. Sexual maturity in males happened from 8 to 18 years and in females from 14 to 26 years. In the Yangtze River, the spawning migration route was cut in 1981 by the construction of the Gezhouba Dam and its spawning ground is now located below the dam. The artificial spawning has been performed since 1983. In 1997, the aquaculture of this species began on large scale in China, and the offspring at different ages has been grown since then. It is necessary to establish a technique to obtain the gonad tissue samples and quickly determine the sex in the young individuals. In this study, surgical procedures were used to inspect the gonads and obtain their tissue samples ( n=51), at 1.5-5.6 years old and body weight 2.6-35.5 kg. It showed that the fish at the age of 5 to 5.6 years (18-35.5 kg BW) were good candidates for sexing because all of the gonads at that ages could be sexed by gross examination. When water temperature was 14.3-30 ℃ in the operation, the incision site was the ventral midline or 1-4 cm off the ventral midline; the incision was 4-5.5 cm long (2.6-9.7 kg BW) or 3.8-7.5 cm long (13.5-35.5 kg BW); about 0.5 cm^3 gonad tissue was taken; the incision was closed by cruciate suture or single sutures using silk thread, and the time for operation out of tank was 20-30 min; the gonad could be examined grossly and sampled, and 94.1%(48 /51) animals survived, with the incisions healing in 15-40 d and the suture material clearing away. Under the conditions above, the incision healed faster when water temperature was higher and the incision was shorter with single sutures pattern.