达里湖高原鳅人工繁殖技术初步研究

Study on The Artificial Propagation of Triplophysa dalaica

从达里湖运进2~4龄、体质量17.6~34.5g的野生达里湖高原鳅Triplophysa dalaica亲鱼3000多尾,经春季池塘培育至性腺成熟,于2015年5月挑选成熟亲鱼进行催产。雄鱼整头部略圆盾,在眼的部位最窄;胸鳍背面增厚为肉垫,上有刺突;吻部上方有肉垫隆起,无刺突。注射HCG 100 IU＋LRH-A_25μg/kg的催产效果较好。催产20尾雌鱼中17尾产卵,获受精卵5.02万粒,孵出鱼苗2.30万尾,催产率、受精率、孵化率分别为85.0%、65.6%和69.8%。达里湖高原鳅成熟卵为浅黄色,卵径（0.932±0.01）mm,遇水后具强粘性。水温18℃时,受精后70h出膜,初孵仔鱼平均全长（3.47±0.06）mm,3d后卵黄囊完全吸收,能平游、摄食。在自然水温16~25℃下养殖30d平均全长2.89cm。

The wild 2~4 year old fish Triplophysa dalaica with body weight of 17.6~34.5 g was collected from Dali Lake and raised to maturity in a pond and induced to spawn by injection of hormone in May of 2015. The males have secondary sexual characters including slightly roundhead, and the narrowest in the eye position. There are pads with a thorn in pectoral fin thickening, and a meat pad without thorn is located on top of the head. The best spawning was observed in the fish injected with HCG＋LRH-A2 at a dose of 400IU＋5μg/kg body weight with spawning success of 85%（17 females spawned /20 females injected）. A total of 5.02 ×104 fertilized eggs were obtained with fertilizing rate of 65.6% and the 23000 larvae were hatched with hatching rate of 69.8%. The strong adhesive mature eggs were pale yellow in color and had（0.932±0.01）mm in diameter and the larvae were hatched in 70 h at 18℃.The newly hatched larvae had body length of（3.47±0.06）mm, and the yolk sac was exhausted completely to swim 3 d after hatching. The 30 days old juveniles had average total length of 2.89 cm at natural water temperature 16~25℃.