仿生态养殖短须裂腹鱼母本繁殖特性研究

Reproductive Performance of Female Schizothorax wangchiachii Farmed in Imitation Ecological Ponds

为研究仿生态养殖短须裂腹鱼成熟雌鱼不同阶段繁殖性能,从环形仿生态养殖池挑选出健壮的短须裂腹鱼雌、雄亲鱼1593尾(♀393,♂1200),分别暂养于4口和3口75 m^2(25 m×3 m)流水池中,每口雌鱼暂养池混放5尾雄鱼。待雌、雄鱼相互追逐,则一次性注射促黄体激素释放激素类似物A2型(LHRH-A216μg/kg)+马来酸地欧酮(DOM 5 mg/kg)+绒毛膜促性腺激素(HCG 1400IU/kg)混合物催产,24 h后每6 h挤压雌鱼腹部观察,把即将产卵的雌鱼转至产房,用80 mg/L间氨基苯甲酸乙酯甲磺酸盐麻醉后人工挤卵,干法授精,测量393尾雌鱼体长、体质量、受精卵卵径,鉴定年龄,统计催产率、受精率、产卵量、相对产卵量和相对受精量。研究结果表明,雌短须裂腹鱼属匀速生长,4龄可达初次性成熟,生长方程为m=7.345×[1-e^-0.092(t+2.733)]2.92,理论生长拐点为9.2龄,拐点对应体质量和体长为2.33 kg和54.5 cm,理论最大体质量和体长为7.345 kg和80.5 cm。卵径、绝对产卵量和相对产卵量均随年龄逐渐增大,且初次性成熟后3年内增速快,其群体平均值分别为(3.97±0.36)mm、(1.71±0.84)万粒和(8.7±3.0)粒/g;催产率、受精率和相对受精量则均呈现为初次性成熟后快速升高后逐渐降低的趋势,最高值时分别为9龄(81.7%)、10龄[(92.7±4.9)%]和10龄[(8.1±2.6)粒/g],其群体平均值分别为76.0%、(88.9±10.9)%和(7.4±2.7)粒/g。综合比较雌短须裂腹鱼生长特性、催产率和相对受精量,可知9~11龄时繁殖性能最佳,7~8龄时次之,12~14龄时最低,低于7龄的宜为后备亲鱼,高于14龄的则应淘汰。

A total of 1593 brooders(♀393,♂1200)of Schizothorax wangchiachii were selected from a circular eco-culture pond,and reared in four and three 75 m^2(long 25 m×wide 3 m)flowing water ponds at a ratio of♀1∶♂5,respectively.When the males and females were chasing each other,the mixture of luteinizing hormone-releasing hormone analogue A2(LHRH-A216μg/kg)+diethyl ketone maleic acid(DOM 5mg/kg)+chorionic gonadotropin(HCG 1400 IU/kg)was injected into the fish who were squeezed the female abdomen to obtain eggs every 6 h after 24 h by anesthetizing with 80 mg/L MS-222,artificial fertilization,dry insemination,and measured the body length,body weight,and age in 393 females and egg diameter of fertilized eggs,and the rates of fertilization,spawning success,and relative and absolute fecundity in order to study the reproductive performance of mature female S.wangchiachii in aquaculture.The results showed that the females had homometric growth and expressed as Von Bertalanffy equation as m=7.345×[1-e-0.092(t+2.733)]2.92,with the growth inflection age of 9.2 year old,body weight of 2.33 kg and body length of 54.5 cm,and the maximum body weight of 7.345 kg and body length of 80.5 cm.The female had the first sexual maturity at age of 4,with average egg diameter of(3.97±0.36)mm,with increase in relative and absolute fecundity as age,especially in the first three years of sexual maturity,and the average absolute fecundity of(1.71±0.84)×10^4 eggs and relative fecundity of(8.7±3.0)eggs/g.There were rapid increase in spawning success,fertilization,and relative fertilized egg amount since the first sexual maturity,with the maximal spawning success at 9 years old(81.7%),the maximal fertilization at 10 years old[(92.7±4.9)%],and the maximal relative fertilized egg amount at 10 years old[(8.1±2.6)eggs/g].In conclusion,the best reproductive performance was found in 9—11 years old females,followed by 7—8 years old females,and the worst in 12—14 years old females,less than 7 years old females as broodstock,and elimination of more than 14 years old broodstock.