黄渤海蓝点马鲛繁殖群体渔业生物学特征研究

The fisheries biology of the spawning stock of Scomberomorus niphonius in the Bohai and Yellow Seas

利用2016年4-5月、2017年4月在黄、渤海调查采集的350尾蓝点马鲛(Scomberomorus niphonius)繁殖群体的生物学数据,对该繁殖群体的生物学特征进行了分析研究。结果表明:该繁殖群体的叉长范围为406～1010 mm,体重范围为533～7245 g,年龄组成为1～10龄,其中1龄与2龄个体分别占总数的39.2%与33.7%。采用Von Bertalanffy生长方程表示其生长特性,生长参数分别为L_∞=1246.9mm,K=0.11;雌雄性比为1:1.49,3龄前雄性个体数占优势,3龄后雌性个体数占优势。蓝点马鲛的产卵期在4～6月,产卵盛期为4～5月;其绝对繁殖力范围为9.2～127.5万粒/尾,平均50.5万粒/尾;绝对繁殖力随着年龄、叉长的上升逐渐增大,7龄后出现衰退现象。蓝点马鲛的优势饵料生物为玉筋鱼(Ammodytes personatus)、细鳌虾(Leptochela gracilis)。与历史记录比较,蓝点马鲛低龄化、小型化现象更加突出,摄食结构改变,繁殖期提前,繁殖力水平有减小的趋势。

Scomberomorus niphonius is widely distributed in the Bohai Sea, Yellow Sea, and East China Sea. The species is of commercial importance, with an annual catch of over 100000 t in the Bohai and Yellow Seas. As the recent recession in traditional fishery resources becomes more serious, S. niphonius plays an increasingly impor-tant role in Chinese fisheries. Studies on the biological characteristics of S. niphonius were reported in the 1980s and 1990s in China, but have been rare in recent years. Information on biological characteristics such as growth and maturity may change with the recession of fishery resources. Therefore, better knowledge of S. niphonius bi-ology is needed to inform the scientific management of this species in the China Sea. The biological characteristics of S. niphonius were studied on the basis of 350 samples of spawning stocks collected from April to May 2016 and April 2017 in the Bohai and Yellow Seas. The fork length of this spawning stock ranged from 406 to 1010 mm, and the body weight ranged from 533 g to 7245 g. The ages of S. niphonius ranged from 1＋ to 10＋ years, in which individuals of 1 and 2 years old accounted for 39.2% and 33.7% of the population, respectively. The parameters of the von Bertalanffy growth equation, L？ and K, were 1246.9 mm and 0.11 yr–1, respectively. The sex ratio was 1 ： 1.49 （female： male） in the survey area. There are more males than females under the age of 3 years, and more fe-males than males after age 3. The reproduction of S. niphonius occurs from April to June and is concentrated in April and May. Individual absolute fecundity ranged from 91.6 to 1275.2 thousand eggs/individual, and the mean value was 504.5 thousand eggs/individual. The absolute fecundity increased with age and fork length and then began to decline after 7 years old. The dominant prey organisms were Ammodytes personatus and Leptochela gracilis. S. niphonius tended to have a lower age structure, miniaturized body size, and decreased fecundity com-pared to previous studies, and there were substantial changes in their dietary composition and breeding season.