太平洋中东部海域大眼金枪鱼胃含物分析

Analysis on stomach content of bigeye tuna (Thunnus obesus) in the eastern-central Pacific Ocean

  • 摘要: 大眼金枪鱼(Thunnus obesus)是金枪鱼延绳钓的主要捕捞对象,分析其胃含物组成有助于更好地认识其摄食特征。根据2010年9月至2011年1月在太平洋中东部海域延绳钓渔业中采集的大眼金枪鱼胃含物样品,采样传统胃含物分析法对大眼金枪鱼摄食种类组成、多样性和摄食强度进行研究。结果表明,大眼金枪鱼的胃含物主要包括鱼类、头足类和甲壳类,其中优势饵料生物隶属于柔鱼科、褶胸鱼科和蛇鲭科。摄食强度组成随叉长变化而显著变化(单因素方差分析,P0.05)。空胃的个体所占比例很高,且随性腺成熟度增加而增大,成熟度Ⅰ期至Ⅴ期的空胃率依次为32.7%、38.4%、47.5%、50.7%和50.7%。摄食强度组成不存在显著的性别间差异(K-S 检验,P0.05)。各月份摄食强度组成差异显著(单因素方差分析,P0.05),10月平均摄食强度最高,1月最低。

     

    Abstract: Bigeye tuna (Thunnus obesus, BET) is one of the main target species by tuna longline. Analysis on stomach content of BET can improve understandingits feeding characteristics. Based on BET stomach samples collected from longline fishery in the eastern-central Pacific Ocean from September 2010 to January 2011, we analyzed the prey composition, diversity and feeding intensity (i.e., stomach fullness) of BET. The results show that fishes cephalopods, and crustacean were main preys of BET, with dominant prey species groups of Ommastrephidae, Sternoptychidae and Gempylidae. The feeding intensity compositions of BET were significantly different among various fork-length samples as indicated by One-Way ANOVA (P0.05). The proportion of empty stomachs in BET samples which was high, increasingalong with gonad maturity stages (empty stomach percentages were 32.7%, 38.4%, 47.5%, 50.7% and 50.7% for maturity stages Ⅰ~Ⅴ, respectively). There was no significant difference in feeding intensity composition between males and females (K-S test, P0.05). Moreover, the feeding intensity composition differed monthly (One-Way ANOVA, P0.05), with the highest stomach fullness in October and the lowest in January.

     

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