期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
Early life history traits of chub mackerel Scomber japonicus in the Oyashio water revealed by otolith microstructure 被引量:1
1
作者 Xiaolu LI Chi ZHANG +2 位作者 Yongjun TIAN Longshan LIN Shigang LIU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第6期2444-2450,共7页
Information on survival and growth during the early life stage is essential to understand the mechanism of interannual variations in fish recruitment.Chub mackerel Scomber japonicus is a commercially important pelagic... Information on survival and growth during the early life stage is essential to understand the mechanism of interannual variations in fish recruitment.Chub mackerel Scomber japonicus is a commercially important pelagic fish widely distributed in the northwestern Pacific.Its catch showed large fluctuations with changes in distribution and migration under climate change and strong fishing.We determined the hatch dates and growth rates of young-of-the-year of chub mackerel through otolith microstructure using samples collected in the Oyashio water in autumn 2018.Results show that the ages of young chub mackerel ranged between 120 and 180 d,and the estimated hatch date lasted from midJanuary to late May with a peak from mid-March to mid-April.Average otolith daily increment width during the early life stages(from hatching to 25 d)showed an increasing trend.Chub mackerel grows slowly in the first 10 d,and then grows faster during the 10thto 25thd.Three groups with dissimilar growth histories and migration routes were identified using unsupervised random forest clustering analysis,but all eventually converge on the same nursery ground.The faster growth of young-of-the-year chub mackerel leads to better recruitment due to the hypothesis of growth-dependent mortality.Most chub mackerels hatched in March and April,the spawning period is longer and earlier,which could lead to strong year classes.These findings on population composition and life history traits of young-of-the-year of chub mackerel provide valuable information on its recruitment processes during the period of stock recovery. 展开更多
关键词 Scomber japonicus otolith microstructure growth history unsupervised random forest clustering RECRUITMENT
下载PDF
Otolith Microstructure Analysis Reveals Different Growth Histories of Japanese Sardine (Sardinops melanostictus) in the Oyashio Waters
2
作者 LIU Chunlin ZHANG Chi +4 位作者 TIAN Yongjun WANG Liangming LIN Longshan LI Yuan WATANABE Yoshiro 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第1期236-242,共7页
After decades of low year classes,the stock of Japanese sardine(Sardinops melanostictus)has begun to recover since the mid-2000s.The hatch dates and otolith growth rates of age-0 juvenile sardine,which were collected ... After decades of low year classes,the stock of Japanese sardine(Sardinops melanostictus)has begun to recover since the mid-2000s.The hatch dates and otolith growth rates of age-0 juvenile sardine,which were collected in the subarctic Oyashio waters in autumn 2018,were determined from an otolith microstructure analysis.The sardines were hatched from late January to late April,while mostly in February and March.The otolith growth rate increased continuously up to 60 d after hatching and thereafter de-creased.The revealed growth rate in a crucial growth period is faster than that reported for juvenile sardines collected in the 1990s,which is coincided with the recent recovery trend of the sardine stock.Two groups with different hatch dates,growth histories,and migration routes were identified using unsupervised random forest clustering analysis.They were considered inshore and offshore migration individuals in accordance with recent researches.In the offshore group,a high proportion of sardine juveniles hatched late and grew faster in the Kuroshio-Oyashio transitional waters,a finding consistent with the hypothesis of growth-rate-dependent re-cruitment.This finding on the population composition and growth rate of juvenile sardine in the Oyashio waters can be a basis for an improved prediction of their survival and provides us with valuable information on the recruitment processes of this stock during the period of stock recovery. 展开更多
关键词 Sardinops melanostictus otolith microstructure growth history unsupervised random forest clustering RECRUITMENT
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部