SEX RATIO VARIATION AND ITS RELATION TO MARINE ENVIRONMENTS FOR DOSIDICUS GIGAS IN THE EQUATORIAL WATER OF SOUTHEAST PACIFIC
The sex ratio,as the foundation for the propagation of sexually reproducing species,is substantial for the maintenance of species populations.To investigate the variations in the sex ratio of the jumbo flying squid(Dosidicus gigas)and its relationship with the environmental conditions of their habitat,samples were selected from the catches of Chinese distant-water jigging vessels operating in the equatorial waters of the southeast Pacific from January to September in 2017～2019.The temporal and spatial variations in sex ratio were analyzed,and a mixed model was employed to examine the relationship between the sex ratio and environmental variables of the habitat.Results indicate that the overall sex ratio of the jumbo flying squid ranged from 1∶1 to 4.67∶1,showing a decreasing trend over the sampling months.In contrast,the sex ratio of mature individuals ranged from 0∶1 to 0.34∶1,exhibiting an increasing trend over time.There was a negative relationship between the overall sex ratio and the percentage of mature individuals.When the percentage of mature individuals exceeded 10％,the sex ratio of mature individuals showed an increasing trend.Additionally,the overall sex ratio was significantly correlated with the sampling latitude × longitude,and was also significantly associated with environmental variables including sea surface temperature,sea surface salinity,sea surface height,and chlorophyll-a concentration.However,the sex ratio of mature individuals did not show a significant correlation with the sampling latitude × longitude or with the environmental variables of the habitat.The findings suggest that the variations in the sex ratio of the jumbo flying squid are primarily related to gonadal development,and the overall sex ratio is closely linked to the marine environment.Conversely,the mature individuals exhibits a strong environmental adaptability to maintain a relatively stable sex ratio.
万方数据
维普
