Impacts of El Nino on the somatic condition of Humboldt squid based on the beak morphology  

作　　者：HU Guanyu YU Wei LI Bai HAN Dongyan CHEN Xinjun CHEN Yong LI Jianhua 

机构地区：[1]College of Marine Sciences,Shanghai Ocean University,Shanghai 201306,China [2]National Distant-water Fisheries Engineering Research Center,Shanghai Ocean University,Shanghai 201306,China [3]Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources,Ministry of Education,Shanghai Ocean University,Shanghai 201306,China [4]School of Marine Sciences,University of Maine,Orono,Maine 04469,USA [5]Collaborative Innovation Center for National Distant-water Fisheries,Shanghai 201306,China [6]College of Fisheries,Ocean University of China,Qingdao 266003,China

出　　处：《Journal of Oceanology and Limnology》2019年第4期1440-1448,共9页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(Nos.NSFC41306127,NSFC41276156);the National Science Foundation of Shanghai(No.13ZR1419700);the Innovation Program of Shanghai Municipal Education Commission(No.13YZ091);the Operational Application Project of Satellite Ocean Remote Sensing(No.201701004);the Shanghai Leading Academic Discipline Project(Fisheries Discipline)

摘　　要：The Humboldt squid Dosidicus gigas has a short life span, and environmental variability plays a significant role in regulating its population dynamics and distribution. An analysis of 1 096 samples of D. gigas collected by the Chinese commercial fishing vessels during 2013, 2014, and 2016 off the Peruvian Exclusive Economic Zone, was conducted to evaluate the impacts of El Nino events on the somatic condition of D. gigas. This study indicates that the slopes of all beak variables in relation to mantle length (ML) for females were greater than those of males during 2013, 2014, and 2016, and slopes of the upper crest length and the lower rostrum length significantly differed between females and males in 2013 (P<0.05). Variation in the slopes for beak variables among years was studied;no significant difference was observed (ANCOVA, P>0.05). The Fulton's condition coefficients (K) of females and males in 2013 and 2014 were significantly greater than those in 2016 (P<0.01). The K values of females were greater than those of males in 2013, 2014, and 2016, and K values significantly differed between females and males in 2013. In normal years, the chlorophyll a (Chl a) concentration showed an N-shaped variability from January to December. However, in the El Nino period, it tended to weaken the upwelling coupled with warm and low Chl a concentration waters. We suggest that the poor somatic condition of D. gigas during the El Nino year was resulted from the low Chl a concentration in the waters, and the abundance of D. gigas would decrease due to the unfavourable environment and the lack of prey items in the El Nino year.The Humboldt squid Dosidicus gigas has a short life span,and environmental variability plays a significant role in regulating its population dynamics and distribution.An analysis of 1 096 samples of D.gigas collected by the Chinese commercial fishing vessels during 2013,2014,and 2016 off the Peruvian Exclusive Economic Zone,was conducted to evaluate the impacts of El Ni?o events on the somatic condition of D.gigas.This study indicates that the slopes of all beak variables in relation to mantle length(ML)for females were greater than those of males during 2013,2014,and 2016,and slopes of the upper crest length and the lower ro strum length significantly differed between females and males in 2013(P<0.05).Variation in the slopes for beak variables among years was studied;no significant difference was observed(ANCOVA,P>0.05).The Fulton’s condition coefficients(K)of females and males in 2013 and 2014 were significantly greater than tho se in 2016(P<0.01).01).The K values of females were greater than tho se of males in 201 3,2014,and 2016,and K values significantly differed between females and males in 201 3.In normal years,the chlorophyll a(Chl a)concentration showed an N-shaped variability from January to December.However,in the El Ni?o period,it tended to weaken the upwelling coupled with warm and low Chl a concentration waters.We suggest that the poor somatic condition of D.gigas during the El Ni?o year was resulted from the low Chl a concentration in the waters,and the abundance of D.gigas would decrease due to the unfavourable environment and the lack of prey items in the El Ni?o year.

关 键 词：El Nino event Dosidicus gigas somatic condition abundance beak morphology 

分 类 号：P[天文地球]