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 collect...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.展开更多
The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method fo...The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method for identifying different species by measuring 12 morphological variables of the beaks of Illex argentinus, Ommastrephes bartramii, and Dosidicus gigas that were collected by Chinese jigging vessels. To remove the effects of size, these morphometric variables were standardized using three methods. The average ratios of the upper beak morphological variables and upper crest length of O. bartramii and D. gigas were found to be greater than those of I. argentinus. However, for lower beaks, only the average of LRL(lower rostrum length)/LCL(lower crest length), LRW(lower rostrum width)/LCL, and LLWL(lower lateral wall length)/LCL of O. bartramii and D. gigas were greater than those of I. argentinus. The ratios of beak morphological variables and crest length were found to be all significantly different among the three species(P < 0.001). Among the three standardization methods, the correct classification rate of stepwise discriminant analysis(SDA) was the highest using the ratios of beak morphological variables and crest length. Compared with hood length, the correct classification rate was slightly higher when using beak variables standardized by crest length using an allometric model. The correct classification rate of the lower beak was also found to be greater than that of the upper beak. This study indicates that the ratios of beak morphological variables to crest length could be used for interspecies and intraspecies identification. Meanwhile, the lower beak variables were found to be more effective than upper beak variables in classifying beaks found in the stomachs of predators.展开更多
为了解决目前水质预测中未考虑局部无知性这一问题,提出一种基于幂集置信规则库(Belief rule base with power set,PBRB)的水质预测模型。该模型能够有效融合专家知识与定量数据,并能在描述多种不确定性的同时,将传统的辨识框架扩展到幂...为了解决目前水质预测中未考虑局部无知性这一问题,提出一种基于幂集置信规则库(Belief rule base with power set,PBRB)的水质预测模型。该模型能够有效融合专家知识与定量数据,并能在描述多种不确定性的同时,将传统的辨识框架扩展到幂集,使其能够很好地表达无知性从而提高水质预测精度。此外,利用协方差矩阵自适应进化策略(Covariance matrix adaptive evolution strategy,CMA-ES)算法对PBRB模型进行优化。仿真结果表明:PBRB模型能准确预测一段时间内水质变化趋势,预测精度高于其他传统方法。展开更多
基金Supported by the National Natural Science Foundation of China(Nos.NSFC41306127,NSFC41276156)the National Science Foundation of Shanghai(No.13ZR1419700)+2 种基金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)
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.41306127 and 41276156)the National Science Foundation of Shanghai(No.13ZR1419700)+3 种基金the Innovation Program of Shanghai Municipal Education Commission(No.13YZ091)the Shanghai Leading Academic Discipline Project(Fisheries Discipline)supported by Shanghai Ocean University(SHOU)International Center for Marine StudiesShanghai Visiting 1000 Talent Program
文摘The cephalopod beak is a vital hard structure with a stable configuration and has been widely used for the identification of cephalopod species. This study was conducted to determine the best standardization method for identifying different species by measuring 12 morphological variables of the beaks of Illex argentinus, Ommastrephes bartramii, and Dosidicus gigas that were collected by Chinese jigging vessels. To remove the effects of size, these morphometric variables were standardized using three methods. The average ratios of the upper beak morphological variables and upper crest length of O. bartramii and D. gigas were found to be greater than those of I. argentinus. However, for lower beaks, only the average of LRL(lower rostrum length)/LCL(lower crest length), LRW(lower rostrum width)/LCL, and LLWL(lower lateral wall length)/LCL of O. bartramii and D. gigas were greater than those of I. argentinus. The ratios of beak morphological variables and crest length were found to be all significantly different among the three species(P < 0.001). Among the three standardization methods, the correct classification rate of stepwise discriminant analysis(SDA) was the highest using the ratios of beak morphological variables and crest length. Compared with hood length, the correct classification rate was slightly higher when using beak variables standardized by crest length using an allometric model. The correct classification rate of the lower beak was also found to be greater than that of the upper beak. This study indicates that the ratios of beak morphological variables to crest length could be used for interspecies and intraspecies identification. Meanwhile, the lower beak variables were found to be more effective than upper beak variables in classifying beaks found in the stomachs of predators.
文摘为了解决目前水质预测中未考虑局部无知性这一问题,提出一种基于幂集置信规则库(Belief rule base with power set,PBRB)的水质预测模型。该模型能够有效融合专家知识与定量数据,并能在描述多种不确定性的同时,将传统的辨识框架扩展到幂集,使其能够很好地表达无知性从而提高水质预测精度。此外,利用协方差矩阵自适应进化策略(Covariance matrix adaptive evolution strategy,CMA-ES)算法对PBRB模型进行优化。仿真结果表明:PBRB模型能准确预测一段时间内水质变化趋势,预测精度高于其他传统方法。
