赤眼鳟的繁殖生物学

The Reproductive Biology of Barbel Chub

对赤眼鳟(Squaliobarbus curriculus)的性腺发育、性征、繁殖力、性比、繁殖习性、胚胎发育和胚后发育进行了研究.赤眼鳟初次性成熟年龄为2冬龄.繁殖季节为4月下旬至8月上旬,以5～7月为盛产期.网箱饲养已达性成熟年龄的赤眼鳟性腺成熟系数大于池养及江河野生的.其相对繁殖力为252.8粒/g,高于池养者31.05%,高于野生鱼28.0%.雄鱼体形比雌鱼长,成熟雄鱼在繁殖季节胸鳍具有颗粒状珠星,非繁殖季节珠星消失.雌雄比接近1:1.赤眼鳟属敞水性产卵类型,为不分批产卵鱼类.广西江河的赤眼鳟天然产卵场有11处,主要分布于郁江,左江和右江各有1处.在水温28～28.5℃的情况下,自受精到孵化所需时间为16 h 10 min,积温453℃·h.鱼苗经17 d发育,鳞片完全,体形、习性与成鱼相似.

Barbel Chub （Squaliobarbus curriculus ） reached the first sexual maturity in the second year. The reproduction season started from late April to early August, with the best season from May to July. During May to July, the maturity coefficient of female Barbel Chub averaged 18.4% and its average fecundity was 199.5 eggs/g. The male Barbel Chub is longer than the female. The matured male usually had spotted pearl organs on its pectoral fins during reproduction season, which disappeared afterwards. The sexual ratio between the male and female was 1：1. Barbel Chub was an open water spawner that did not spawn by batches. 11 natural spawning grounds have been found in the rivers in Guangxi, China. Expect for one spawning ground in each Zuo River and You River, the rest were evenly distributed in Yu River. At water temperature of 28 - 28.5 ℃, the incubation starting from fertilized eggs usually took 16.1 hours. The total accumulated temperature was 453 degrees. The fry were fully developed with complete scales in 17 days and get the similar characteristics to their adults such as body shape, living habits and habitat.