摘要
研究鄱阳湖刀鲚群体的生殖特征和条件状况,为制定开发利用渔业资源的政策提供基础资料,以实现鄱阳湖刀鲚资源的可持续开发和保护。2013、2014年4-7月,分别在鄱阳湖及湖口八里江段进行了实地渔业资源调查,随机抽样定置网、流刺网和拖网采集的鄱阳湖刀鲚样本共658尾,测量了体长、体重、净重、性腺重和性别。雌性287尾、雄性371尾,体长18.6~38.1 cm、体重16.3~198.2 g。雌性刀鲚的体长和体重均大于雄性(P<0.01),雌、雄个体的体长和体重差异均为极显著(P<0.01)。随着体长的增加,雌雄体重差异越大;同等体长的雌性体重大于雄性。6月中旬、下旬的刀鲚卵巢发育仍参差不齐,有些可挤出卵粒,已发育到Ⅳ期末和Ⅴ期,有些还处在Ⅳ期初,但成熟系数在2.0以下的个体数量已显著减少。绝对繁殖力为960~13 820粒,相对繁殖力为123.4~753粒/g。平均丰满度为0.30±0.03(0.19~0.45)。鄱阳湖刀鲚雌雄比在1∶1.25~1.44,表现出雄多雌少的现象;刀鲚繁殖种群已呈现出逐渐变小的趋势,资源已出现严重的过度利用。
Coilia ectenes is an anadromous species and Poyang Lake has been a critical.spawning ground in the Yangtze River basin. However, in recent years, the Coilia ectenes resource in the Poyang Lake has decreased sharply. In this study, the reproductive characteristics and condition of the Poyang Lake population were studied to provide basic data for decision making on fishery resource development and utilization, as well as the protection and sustainable development of Coilia ectenes resources in Poyang Lake. A field survey was conducted in Poyang Lake and the Balijiang Section of the Yangtze River （Hukou County） from April to July of 2013 and 2014. A total of 658 specimens were obtained using stationary fishing nets, drift-gill nets and trawl nets. Biological parameters of the specimens were measured, including body length （ -＋0.1mm）, body weight, net weight （ ＋0.1 g）, gonad weight （ _＋0.1 rag） and gender. Female Coilia ectenes in stages IU - V were randomly selected and their eggs were coun- ted to determine absolute and relative fecundity. The body length and body weight ranges of the specimens （fe- male： 287, male： 371） were, respectively, 18.6-38.1 cm and 16.3- 198.2 g and averaged （24.12 ± 3.14） cm and （44.15 ±21.42） g. The body length and weight of female Coilia ectenes were greater than those of the males and the differences were highly significant （ P 〈 0.01 ）. The weight of females was greater than that of males of the same length and the relative difference increased with length. There was a highly significant positive correlation in both genders between gonad weight and body weight （P 〈 0.01 ）. During the survey, we found that the ovary of Coilia ectenes developed unevenly ugh middle and late June. Eggs could be squeezed from some fe- male Coilia ectenes （late stage IV and stage V）, while others were still at early stage IV, although individuals with a maturation coefficient below 2.0 had dramatically decreased. The range of absolute fecundity of Coil
出处
《水生态学杂志》
CSCD
北大核心
2017年第3期83-88,共6页
Journal of Hydroecology
基金
赣鄱英才555工程项目(赣财教指[2012]213号)
关键词
鄱阳湖
刀鲚
生殖特征
Poyang Lake
Coilia ectenes
reproductive characteristics
