上海海洋大学学报2017，Vol.26Issue(4)：570-579,10.DOI:10.12024/jsou.20161101910
热带大西洋拟锥齿鲨资源动态和空间分布研究
Preliminary analysis of crocodile shark (Pseudocarcharias kamoharai) resources information and spatial distribution in the tropical Atlantic Ocean
摘要
Abstract
Crocodile shark (Pseudocarcharias kamoharai) is a common bycatch species in tropical Atlantic tuna longline fishery.This species is mostly distributed at the topmost parts of the marine ecosystem and plays a very important role in the stability and diversity of the marine ecosystem.A total of 1 561 ind.crocodile sharks were recorded according to the biological data collected by Chinese longline fishery observers in the tropical Atlantic Ocean from 2010 to 2015 and the preliminary analyses about its resource information and spatial distribution were made.The results were summarized as follows: In the study area (6.33°S-17.43°N,18.25°W-42.03°W), the highest concentration of the CPUE area was in the zone 5°N-10°N, 20°W-30°W;the CPUE value was in the range: 0.00-3.94, and the average was 0.83.From 2010 to 2015, CPUE showed a variation trend , but the upward trend was not significant.The Chondrichthyes percentage in total proportion of the catch decreased;the total number of crocodile sharks accounted for 5.8% of total number of fish caught, accounting for 22.5% of the total number of Chondrichthyes bycatch.The higher average CPUE values of the tropical Atlantic crocodile sharks were recorded in December, and from January to March.The largest fork length class (fork length range of 85-90 cm) of the crocodile sharks were distributed in the regions 5°N-7.5°N, 27.5°W-37.5°W and 5°N-0°,25°W-30°W.Crocodile shark hook depth ranges between 140-313 m, the average observed depth was 221 m.The frequency of 1-3 hooks (140-212 m) is the largest, accounting for 55.59% of the total catch rate.There was no significant difference in the hook position of the crocodile shark in different months from October to April.Crocodile sharks were obviously distributed in the shallow water layer during pregnancy.There was no significant difference between feeding level and hook position of crocodile sharks.关键词
拟锥齿鲨/热带大西洋/空间分布/CPUE/钩位Key words
Pseudocarcharias kamoharai/the tropical Atlantic Ocean/resource distribution/CPUE/hook depth range分类
农业科技引用本文复制引用
王浩展,戴小杰,高春霞,王家启..热带大西洋拟锥齿鲨资源动态和空间分布研究[J].上海海洋大学学报,2017,26(4):570-579,10.基金项目
农业部公海渔业研究财政专项(08-54) （08-54）
