【摘要】 根据2010年春季对台湾海峡中部日本鲭的生物学测定数据及怀卵量计数结果,对其产卵群体的生物学特征进行了研究.结果表明:日本鲭产卵群体性比符合1∶1的雌雄性比关系;叉长范围212.00~271.00 mm,平均244.76 mm,优势组230.00~260.00 mm;雌鱼最小性成熟叉长225.00 mm,雄鱼最小性成熟叉长221.00 mm;体质量范围110.99~242.00 g,平均170.97 g,优势组130.00~220.00 g.雌雄个体的性腺成熟度均以Ⅳ~Ⅴ期为主,摄食强度均较高,雌鱼平均摄食强度为2.00,雄鱼平均摄食强度为2.25;雌鱼的平均摄食强度随性腺成熟度的提高呈下降趋势,而雄鱼正好相反;在达到完全性成熟前,雌雄鱼的性腺指数GSI都随着性腺的发育而增加,雌鱼的平均性腺指数GSI略高于雄鱼;绝对怀卵量5.283 5万~16.884 7万粒,平均10.405 0万±0.611 8万粒;叉长相对怀卵量227~625粒/mm,平均423±22粒/mm.随着叉长的增加,怀卵量也持续增加.叉长250.00 mm以上个体怀卵量相对于250.00 mm以下个体出现大幅增加趋势.与20世纪80年代研究结果相比,目前该海域日本鲭的大量性成熟年龄由2龄提前为1龄,最小性成熟年龄即为大量性成熟年龄;产卵群体年龄组成由1~5龄转变为1~2龄,优势组由2~3龄下降为1龄;产卵群体平均绝对怀卵量下降了33.23%.因此,为了保护该海域日本鲭资源并提高种群数量和年龄结构,应该首先制定合理的最小开捕叉长,同时在其春汛产卵期采取必要的休渔措施及在主要产卵场设立保护区.更多还原

【Abstract】 According to the biological data and fecundity count of chub mackerel(Scomber japonicus) collected from central Taiwan Strait in spring,2010,the biological characteristics of the spawning stock were studied. The results show that the male to female ratio of the spawning stock was 1∶ 1. The fork length of the stock ranged from 212. 00 mm to 271. 00 mm with an average value of 244. 76 mm,and the dominant group ranged from 230. 00 mm to 260. 00 mm. The minimum fork length of the maturity was 225. 00 mm and 221. 00 mm for female and male fish,respectively. Body weight ranged from 110. 99 g to 242. 00 g with an average of 170. 97 g and the dominant group ranged from 130. 00 g to 220. 00 g. The dominant individual gonad maturities were in stage of Ⅳ and Ⅴ for both male and female fish. The feeding intensity was 2. 00 for female and 2. 25 for male fish,which is higher. The average feeding intensity declined with the improvement of gonad maturity for female fish,while the reverse is true for males. Before reached full sexual maturity,GSI of both male and female fish increased with the gonad development. GSI of female fish was slightly higher than that of male fish. The absolute fecundity was 5. 283 5 × 104~ 16. 884 7 × 104 grains with an average value of(10. 405 0 ± 0. 611 8) × 104grains. The relative fecundity with fork length ranged from 227 to 625 grain / mm with an average value of 423 ± 22 grain / mm. The fecundity is increasing with the fork length. The fecundity increased sharply for fish with fork length over 250. 00 mm in contrast to the fork length less than 250. 00 mm. Compared with the data from 1980’s,the major sexual maturity age has advanced from 2 years to 1 year. The minimum sexual maturity age became the major sexual maturity age. The age composition of spawning population has changed from 1 ~ 5 years to 1 ~ 2 years and the dominant group decreased from 2 ~ 3 years to 1 year. The average fecundity of spawning population has decreased by 33. 23%. Therefore,we should formulate a reasonable minimum capture fork length at first and at the same time take measures to prohibit the fishing in spring spawning season and establish protected areas in important spawning grounds in order to protect the resources and increase the population sizes and age structure of the fish.更多还原