黄渤海蓝点马鲛繁殖生物学的研究

STUDIES ON THE REPRODUCTIVE BIOLOGY OF SCOMBEROMORUS NIPHONIUS IN THE YELLOW SEA AND BOHAI SEA

根据1960－1993年在渤海、黄海及东海北部渔业生产和调查中收集的19096尾蓝点马鲛样品，进行繁殖生物学研究。结果表明，卵巢成熟度依据外部形态观察、切片镜检、卵内结构分析、卵径测量和成熟系数计算等分为Ⅰ-Ⅵ期；性腺周年内成熟一次，并存在发育、成熟、产卵后和恢复阶段；产卵期为5—7月，盛期在5月中旬至6月中旬，由南至北逐渐推迟；性成熟年龄因捕捞强度增加而提前，明显分为70年代后期为界的前后两个阶段，前阶段2龄开始成熟，后阶段1龄即性成熟；雌性最小性成熟叉长和体重分别为395mm和495g，雄性分别为360mm和355g；性比为50.2:49.8因年龄和不同生活阶段而异，2龄前和越冬期间雄性为多，3龄后和生殖季节雌性为多。

This study of the repredutive biology of Scomberomorus niphonius isbased on biologic test, microscopic exandnation of organic tissues, and biostatistics of 19 096 samples collected from 1960 to 1993 in the Bohai Sea, Yellow Sea and Northern East China Sea.The ovarian condition is divided into 6 maturation stases according to themorphologic dsacter of the ovary, gonadosomatic index (GSI), ova diamter (OD),and ova structure. In the lst stage, the OD is 0.005-0.014mm. The sex cannot bedistinguished by the eyes. In the 2nd stage, the GSI is 2.9×10-3- 10.2×10-3, OD is0.007-0.460mm, but the ova can be hardiy seen by the eyes. In the 3rd stage, therecan be seen blood vessel and ova on the sthe of the ovary. GSI is in 15.2 ×10-3-81.9×10-3, OD is 0.175- 0.950mm. In the 4th stag, there can be easily seen withthe eyes the big of little ova on the surface of ovary. The GSI is 78.0×10-3-230.0 ×10-3, OD is 0.300- 1.475mm.In the 5th stage, there can be seen man matured ovain the ovary' The GSI is 117.2×10-3- 393.2×10-3, OD is 0.315- 2.030mm. In the6th stage, there are no big ova in the ovary. The ovary color is changed to theredness of the skin. The GSI is 51.4× 10-3- 89.3 ×10-3, OD is O.350- 1.250mm.The yearly gonadic is divided into 4 phases, i'e' development from March to April, maturation from May to June, spawning from July to August, andconvalescence from SePtember to February of the next year。 The spawning period isfrom May to July and the peak period is from ndddle of May to ndddle of June'The spawning period in the north is later than that in the south.The matured age is moved up because of increasing fishing effort, and is 2 yearslod after, and one year old before, the 70' s' The ndnimum matured fork length andbody weight are 395nun and 495g for females and 36(han and 355g for males'.The sex radio is 50.2:49.8. Female are more than males among 3 years old individuas and during the spawning period, and males are more than females among 2years old individuas and during the wintering period.