福建九龙江口凤鲚的生物学特征

Biological Characteristics of Coilia mystus in Jiulong River Estuary in Fujian Province

利用2010年9月至2013年8月每季度从福建九龙江口的紫泥、岛美、浮宫3个站点的定置张网和流刺网渔获物中采集的凤鲚样本,分析凤鲚的生物学特性.结果表明:1)九龙江口凤鲚体长分布范围为44~239 mm,优势体长为140~160 mm,体重分布范围为0.20~69.10 g,优势体重为0.20~20 g,体长与体重的关系式为W=1.3×10-6L3.23(R2=0.88,P<0.01,n=927),体长生长方程为Lt=246.75[1-e^(-0.65(t+0.21))],体重生长方程为Wt=64.94[1-e^(–0.65(t+0.21))]3.23,由此可将凤鲚看做匀速生长的鱼类;2)凤鲚夏季洄游至九龙江产卵,性成熟以Ⅴ期为主,冬季摄食强度最强;3)凤鲚的总死亡系数、自然死亡系数和捕捞死亡系数分别为2.0、0.67和1.33.结果说明九龙江口凤鲚资源已经处于过度开发状态,需要采取合理的保护和限制捕捞措施.

In this paper, the biological characteristics of Coila mytus were studied based on the analysis of samples caught by stake nets and gill nets in every quarter from September 2010 to July 2013, in stations Daomei, Zini, and Fugong of Jiulong River Estuary. The results indicated that ： 1） the length of Coilia mystus ranged between 44 to 239 mm, and the dominant length group between 140 to 160 mm; the weight of Coilia mystus was 0. 20 to 69. 10 g, and the dominant weight group between 0. 2 to 20 g. The relationship between length and weight was W = 1.3 × 10-6L323（R2 = 0. 88,P 〈 0.01,n = 927） . The growth equation of body length was L, = 246.7511 - e^-0.65（t＋0.23）] , the growth equation of body weight was Wt = 64.9411 - e^-0.65（t＋0.25 ]3.23 . 2） The Coilia mystus migrated to Jiulong River and spawned in summer. Sexual maturation is mainly in stage V. The highest feeding intensity of Coilia mystus was in winter. 3） The total mortality, nat- ural mortality and fishing mortality were 2. 0, 0. 67and 1.33 , respectively. The Coilia mystus in Jiulong River was overfished, and reasonable protection and fishing measures would be needed.