基于耳石微结构的南海鸢乌贼日龄和生长研究

年龄和生长速度等参数是渔业资源评估和管理的基础。鸢乌贼生命周期短、生长速度快。为研究鸢乌贼的日龄和生长, 利用2016年10月—2017年9月灯光罩网作业方式采集的南海鸢乌贼样本, 通过耳石微结构研究南海鸢乌贼不同种群、性别间的日龄组成和生长的差异, 结果表明: 1) 鸢乌贼中型群日龄范围48~125d, 优势日龄61~80d, 雌雄个体日龄组成差异显著; 微型群日龄范围44~95d, 优势日龄51~70d, 雌雄个体日龄组成差异极显著。2) 鸢乌贼中型群孵化时间为2016年7月—2017年7月, 1月和7—8月为孵化高峰期; 微型群孵化时间为2016年6—10月和12月至翌年2月, 1月和8月为孵化高峰期。3) 中型群雌雄胴长、体质量与日龄分别符合对数和线性关系; 微型群雌雄胴长与日龄分别符合对数和Logistic关系, 而体质量与日龄符合Logistic关系。4) 南海鸢乌贼微型群生长速度大于中型群, 微型群雄性个体生长速度大于雌性, 而中型群雄性个体生长速度小于雌性。通过对耳石生长纹的分析, 了解鸢乌贼的日龄组成、推算孵化时间、选出合适的生长方程及估算生长速度, 为渔业生物学提供基础资料。

Age and growth of Sthenoteuthis oualaniensis based on statolith microstructure in the South China Sea

Age and growth rate are key parameters in fish stock assessment and management. Sthenoteuthis oualaniensis has a short life cycle and a fast growth rate. We employ statolith microstructure to study the difference in age composition, gender and growth of the squid collected from October 2016 to September 2017 by falling-net in the South China Sea in order to study their age and growth. The results show that the age of medium cohort squid ranged from 48d to 125d and that the dominant age was from 61d to 80d. There were significant differences in the composition of female and male ages; age of dwarf cohort squid was between 44d to 95d, and the dominant age was between 51d to 70d. The difference in age composition between male and female individuals is significant. The estimated incubation period for the medium cohort samples was from July 2016 to July 2017; the peak hatching dates were distributed in the months of January and from July to August; the incubation period of the dwarf cohort was from June to October 2016 and from December 2016 to February 2017, and their peak hatching months were January and August. The mantle length, body mass and age of different individuals in the medium cohort could be fit in logarithm and linear relationship. The mantle length and age of different individuals in the dwarf cohort were fit in logarithm and logistic relationship, while the body mass and age were fit in logistic relationship. Our findings indicate that the growth rate of the dwarf group was higher than that of the medium group. The growth rate of the female was lower than that of the male in the dwarf group, but it was the opposite in the medium group. Through the analysis of statoliths growth pattern, we can learn about the age composition of the squid, estimate their hatching time, select their appropriate growth equation, and estimate their growth rate, to provide basic data for fishery biology.