人工繁育条件下的褐菖鲉(Sebastiscus marmoratus)繁殖特性研究

REPRODUCTIVE BIOLOGY OF FISH SEBASTISCUS MARMORATUS UNDER ARTIFICIAL BREEDING

为进一步了解和掌握人工繁育条件下褐菖鲉(Sebastiscus marmoratus)繁殖特性,从2021年5月至2023年6月采集不同月份的褐菖鲉性腺样本,对不同阶段的性腺表型和组织变化、发育周期、生殖腺指数及绝对繁殖力进行分析。结果表明,褐菖鲉为典型的卵胎生鱼类,精巢为全囊成熟型,可分为6期;卵巢为部分同步型,交尾受精后存在妊娠期,共分为7期。各月份性腺分期及生殖腺指数统计结果显示,褐菖鲉繁殖高峰期为每年12月至翌年4月,其中雄性1龄性成熟,雌性2龄性成熟,生殖腺指数在发育阶段显著上升(P<0.05),在交尾排精和产仔后显著下降。此外,1~4龄褐菖鲉的平均绝对繁殖力分别为7087、(19726±4470)、(35924±4190)、(43203±6204)粒,各年龄组存在显著性差异,方程拟合得出绝对繁殖力与体长、体质量呈二项式相关。首次对人工繁育条件下的褐菖鲉性腺发育过程和繁殖特性进行两周年的持续追踪和研究,结果将有助于加深对其繁殖特性的了解,提升规模化繁育技术水平。

To understand the reproductive biology characteristics of Sebastiscus marmoratus under artificial breeding,gonad samples of S.marmoratus in different months from May 2021 to June 2023 were sampled;and the gonadal phenotypes and tissue changes,development cycles,gonad index,and absolute fecundity at different stages were analyzed.Results show that S.marmoratus is a typical ovoviviparous fish;and the sperm enters the ovary to form fertilized eggs and hatch into larvae,which is called as gestation period.The testis was cystic type and could be divided into 6 stages.The ovary was partially synchronized and could be divided into 7 stages.The results of gonad staging and index in each month show that the breeding time of S.marmoratus was from December to April of the next year,during which the male ones were sexually matured in the 1st year and the female was sexually matured in the 2nd year.The gonad index increased significantly during the development stage(P<0.05),decreased significantly after sperm ejaculation and calving.In addition,the average absolute fecundity of 1-4-year-old S.marmoratus were 7087,(19726±4470),(35924±4190),and(43203±6204)grains,respectively.There are significant differences in each age group.The equation fitting shows that the absolute fecundity was binomially related to the body length and mass.This study is the first attempt to conduct continuous tracking on the gonad development course and reproductive characteristics of S.marmoratus under artificial breeding conditions in two years,and shall help deepen the understanding of its reproductive characteristics and improve the level of large-scale breeding technology.