Feeding habits of Sardinops melanostictus based on fatty acid analysis
Sardinops melanostictus is widely distributed in the coastal waters of Japan and the northwestern Pacific Ocean,and it is an important target of fisheries.In order to study the shift in dietary habits during individual development and differences in ecological niche,fatty acid analysis on muscle samples of S.melanostictus collected in the northwestern Pacific Ocean from June to July 2021 was conducted.The fatty acid types and their contents were analyzed among individuals of different body lengths and genders.The results showed no significant differences in fatty acid composition between females and males,and significant differences were found among different body length groups.Principal component analysis revealed that 10 fatty acids were the major fatly acids,with DHA C22∶6n-3 and arachidonic acid C20∶4n-6 contributing the most.The results of non-metric multidimensional scaling and similarity analysis indicated that individuals with body lengths between 100-130 mm and 131-160 mm,as well as those with body lengths between 191-220 mm and 221-250 mm,exhibited a large niche overlap area and no significant difference in fatty acid composition.However,individuals with body lengths between 131-160 mm and 161-190 mm,as well as those between 161-190 mm and 191-220 mm,showed a small niche overlap area and significant differences in fatty acid composition.With increasing body length,the ecological niche width showed a trend of initially increasing and then decreasing.Individuals with small body length mainly feed on phytoplankton and planktonic bacteria,while S.melanostictus in the intermediate body length group undergo a dietary shift when reaching a length of 190 mm,transitioning to mainly consuming herbivorous copepods and zooplankton,and individuals with large body length mainly feed on crustaceans and small fish.The study indicates that differences in fatty acid composition of S.melanostictus are mainly reflected in different body length groups,dietary habits shift during different growth stages,and their ecological niche width and position also change accordingly.
万方数据
维普
