大鳞鲃生长、血清性激素水平和性腺发育的研究

为掌握大鳞鲃Luciobarbus capito F1代生长、血清性激素变化、性腺发育规律和后备亲鱼的初次性成熟时间,采用形态学、组织学和生物化学方法,对养殖条件下1~5龄大鳞鲃的生长特点、血清性激素含量和性腺发育进行了研究。结果表明:随着年龄的增长,大鳞鲃体质量和体长显著增加(P0.05),体长与体质量的关系式为W=0.012L2.99(R2=0.99),Von Bertalanffy生长方程为Lt=107.431-e-0.15(t+0.067)]、Wt=129391-e-0.15(t+0.067)]2.99;1~5龄雄鱼血清中雌二醇(17β-estradiol,17β-E2)含量均低于雌鱼,1~4龄雌鱼血清中17β-E2含量随年龄的增加而升高,在4龄时达到最高值,为(713.00±424.89)pg/m L;5龄雄鱼血清中的睾丸酮(Testosterone,T)含量最高,为(1.12±0.81)ng/m L,其余各龄组血清中T含量无显著性差异(P0.05);大鳞鲃精巢为典型的小叶型结构,精小叶间有间质细胞,小叶内有支持细胞及精小囊结构,精子发育可分为精原细胞、初级精母细胞、次级精母细胞、精子细胞、成熟精子5个时相,5龄雄鱼成熟系数(GSI)达到最大值(0.83%);大鳞鲃卵巢中卵母细胞发育可分5个时相,GSI为0.51%~8.90%,5龄雌鱼成熟系数最大(8.90%)。研究表明,大鳞鲃雌鱼性腺4龄时部分成熟,5龄时完全成熟,雄鱼性腺比雌鱼早成熟一年,在人工繁殖过程中,大鳞鲃后备亲鱼在雄鱼4龄、雌鱼5龄时适合人工药物催产。

Growth,sexual hormone levels in serum and gonadal development in barbell Luciobarbus capito

The growth, gonadal development and serum sex steroids level in 1-5 years old cultured barbel Lucio-barbus capito were investigated using morphological, histological and biochemical methods to study the growth char-acteristics, and relationship between gonadal development and sex steroids level. The results showed that body length ( L) and body weight ( W) were shown to increased significantly with age, with body length-weight relation-ship as W=0. 012L2.99(R2=0. 99), and Von Bertalanffy growth equation Lt=107. 431-e-0.15(t+0.067) ] and Wt=129391-e-0.15(t+0.067)]2.99. There was lower level of serum testosterone(T) in 1-5 years old males than that in 1-4 years old females, with the maximal value (1. 12 ±0. 81) ng/mL at age of 5 years old. The maximal level (713. 00 pg/mL±424. 89 pg/mL) of 17β-E2 was observed in 5 years old females, without significant difference a-mong the other groups. The Leydigs cells, sertolis cells and spermatangia were distributed in the seminiferous lob-ules of the testis as a typical lobular structure. Spermatic development was divided into five stages, spermatogoni-um, first spermatocyte, secondary spermatocyte, spermatoblast and mature sperms, with the maximal gonado-so-matic index(GSI) (0. 83%) in 5 years old males. The ovary development was divided into five stages, with GSI from 0 . 51% to 8 . 90%, and the peak value of 8 . 90% at stage Ⅴ, one year early maturation in male than in fe-male, 4 years old at maturity in male and 5 years old at maturity in female.