浮桥河水库鲂繁殖生物学的研究
REPRODUCTIVE BIOLOGY OF THE FISH, MEGALOBRAMA SKOLKOVII, IN FUQIAOHE RESERVOIR
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摘要: 研究结果表明,浮桥河水库鲂雌性三年性成熟、雄性二年,生殖季节可凭“追星”等副性征辨别雌雄。性成熟后,性腺具有周年变化规律,卵子发育为非同步分批成熟型,水库中为一次产卵,产卵期一般在5-6月,水温18-28℃,产卵场一般位于主河道入库洄水区,卵粘性。多元回归结果:绝对生殖力与成熟系数、体长、体重正相关,而与体高、卵径负相关,相对生殖力除受成熟系数影响较大外,则相对稳定。卵重、卵径主要受成熟系数的影响,与母体生物学指标关系不密切。Abstract: The fish, Megalobrama skolkovii reaches its sexual maturity at 3 years old for females and 2 years for males in Fuqiaohe reservior.In a spawning season the sex can be identified by examining certain secondary sexual characters such as nuptial tubercles of males.The egg development is of an unsynchoronous type and eggs when spawned are adherent. The spawning takes places from May to June when water temperature ranges from 18 to 28℃ in areas of whirling water in the main river course of the reservoir, and is characteristic of single batch type. A multi-parameter regression analysis shows that the absolute reproduction capacity is positively correlated with body length and body weight,but negatively correlated with egg diameter and body depth.Relative reproduction capacity is only influenced by maturing factor.Egg weight and egg diameters are mainly influenced by maturing factor, and are not correlated to biological indexes of brood fish.