美洲鲥的人工繁殖及胚胎发育的研究

Artificial propagation and embryonic development of American Shad,Alosa sapidissima

2007～2009年,利用深井水及设有钢架保温大棚的土池成功进行了美洲鲥(Alosa sapidissima)的亲鱼培育与人工繁殖的研究,同时观察了美洲鲥的胚胎发育过程。结果表明:2龄美洲鲥在池塘中经专池培育并采用激素+不饱和脂肪酸+维生素E投喂、水流刺激等培育措施使雌雄鱼的性腺成熟率达60%～80%。性腺成熟的亲鱼经生态调控促使产卵或人工催产繁殖,生态调控促使产卵中水温保持在16～23℃,池水始终保持流动状态,50对美洲鲥亲鱼自4月中下旬至5月底陆续产卵,共收集鱼卵9.0万粒,平均受精率10%,孵化率70%～80%;人工催产试验中,采用LHRH-A2+鱼类催产助剂、LHRH-A2+HCG+DOM+鱼类催产助剂和LHRH-A2+HCG+鱼类催产助剂3种催产剂配伍,背鳍基部两针注射法,催产率20%～100%,获卵10.57万粒,受精率0～21.5%,孵化率0～70%。美洲鲥受精卵呈卵圆形,卵膜径为(4.03±0.25)mm,根据胚胎的外形与内部主要特征,胚胎发育分为7个生理阶段30个具体发育时期,在水温(20±1)℃下,历时约71 h40 min完成整个胚胎发育过程。

From 2007 to 2009, preliminary success was achieved in Alosa sapidissima artificial breeding and re- production by using phreatic water and earthen ponds with arch-steel shelters. Here we describe the complete em- bryonic development of A. sapidissima in detail. The results showed that the maturation rate of gonad in two-year-old male and female A. sapidissima could reached 60%-80% by feeding of hormone, unsaturated fatty acid and vitamin E as well as water flow stimulation in special rearing ponds. The reproduction of sexually mature fish could be conducted by ecological control or artificial insemination. The temperature of continuous-flow water was maintained at 16-23℃ under ecological condition. From the middle ten days of April to the last ten-day period of May, a total of 90 000 fish eggs were harvested from 50 fish with the average fertility rate of 10% and the hatching rate of 70%-80%. Additionally, sexually mature fish were artificially induced to release gameters by in- tramuscular injection of LHRH-A2 and induced hormone or LHRH-A2, HCG, DOM, and induced hormone, or LHRH-A2, HCG and induced hormone. A total of 105 700 eggs were obtained, and the fertility rate and hatching rate were 0-21.5% and 0~70%, respectively. Fully mature eggs were perfectly spherical and egg diameter was 4.034-0.25 ram. In the present study, embryonic development can be divided into seven periods and thirty stages. The incubation period for Alosa sapidissima was 71 h and 40min at a water temperature of 20℃±1℃.