不同气候条件下南海西沙海域鸢乌贼(Sthenoteuthis oualaniensis)渔业生物学比较研究

为探讨不同气候条件对鸢乌贼(Sthenoteuthisoualaniensis)渔业生物学影响,根据2015年8月(厄尔尼诺年)、2016年8月(拉尼娜发生期)和2017年8月(正常时期)我国灯光罩网船在南海采集的1 970尾鸢乌贼样本,对其胴长、体重、性腺成熟度、胃饱满度、初次性成熟胴长进行了比较研究。结果表明:不同年间鸢乌贼雌雄比例不同, 2017年最高, 2015年次之, 2016年最低;优势胴长组不同,2015年最大, 2017年次之, 2016年最小;优势体重组也不同, 2015年最大, 2017年次之, 2016年最小。协方差分析表明不同年间胴长与体重的关系均不存在性别间显著性差异, 2015、2016和2017年分别最适用线性、幂和指数函数表示;不同年间样本性成熟组成存在差异,雌雄样本性成熟样本分别占对应总数的30.96%和25.40%、46.41%和11.15%、7.35%和28.46%;胃饱满度组成也不同。不同年间初次性成熟胴长不同, 2015、2016和2017年雄性初次性成熟胴长分别为184.12、144.41、132.70 mm;雌性分别为192.66、143.68、188.52 mm。结果表明,不同气候变化引起的海洋环境的变化对鸢乌贼渔业生物学产生影响:温度升高导致鸢乌贼个体减小,性成熟胴长减小,雌雄间的个体差异变大。

COMPARISON IN FISHERY BIOLOGY OF STHENOTEUTHIS OUALANIENSIS IN DIFFERENT CLIMATE EVENTS IN THE SOUTH CHINA SEA

The effect of different climate events on the fishery biology of the purple back flying squid (Sthenoteuthis oualaniensis) was studied based on 1 970 samples collected during El Niño year (August 2015), La Niña year (August 2016), and normal year (August 2017) in the South China Sea. The result indicated that the ratio of females to males was different in the different years, the largest in 2017, the second in 2015, and the smallest in 2016. The mantle length (ML) and body weight (BW) composition was also different in those years with a different high concentration (the largest in 2015, then in 2017, and smallest in 2016). The relationship between the ML and BW was different and there was no significant difference in gender among those years, and the relationship could be best described by linear (2015), power (2016), and exponent (2017) functions. The matured individuals were different in those years, accounting for 25.40%, 11.15%, and 28.46% for males, and 30.96%, 46.41%, 7.35% for females, respectively. In addition, the feeding stages were different. The first mature mantle length was different in those years, being 184.12 mm, 144.41 mm, and 132.70 mm for males; and 192.66 mm, 143.68 mm, and 188.52 mm for females in 2015, 2016, and 2017, respectively. Warmer seawater could resulted in smaller body size, shorter fist mature ML, and enlarged individual difference between male and female.