Ontogenetic changes in isotopic signatures of an omnivorous fish Cultrichthys erythropterus in East Lake Taihu,China  

作　　者：李云凯 张妙 

机构地区：[1]Shanghai Ocean University,College of Marine Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2015年第3期725-731,共7页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(No.41206124);the Ph.D Programs Foundation of Ministry of Education of China(No.23104120001);the "Chen Guang" Project(No.10CG52)

摘　　要：The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter(C ultrichthys erythropterus),commonly found in East Lake Taihu,was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature(δ 13 C) in this study,in which δ 13 C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model,the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However,the stable nitrogen isotopic signature(δ 15N) exhibited an unusual pattern compared with previous studies. The δ 15 N of C. erythropterus showed no relationship with body size,even though dietary changes were observed. This indicated that δ 15 N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events,such as estimating the trophic positions of fish species.The relationship between body size and stable isotopic signatures of the omnivorous Redfin Culter （Cultrichthys erythropterus）, commonly found in East Lake Taihu, was investigated. Previous analyses of C. erythropterus stomach contents have shown that this species undergoes a diet switch from being predominantly zooplanktivorous to piscivorous during its life history. This was confirmed by stable carbon isotopic signature （δ^13C） in this study, in which δ^13C was positively correlated with both standard length and weight. The importance of littoral-benthic resources in supporting C. erythropterus during its lifespan was also demonstrated using a two-source mixing model, the results of which showed a significant increasing trend in the contribution of littoral-benthic energy. However, the stable nitrogen isotopic signature （δ^15N） exhibited an unusual pattern compared with previous studies. The δ^15N of C. erythropterus showed no relationship with body size, even though dietary changes were observed. This indicated that δ^15N alone cannot fully reflect a diet shift in a species and possible variability in isotopic signatures over its life history. This should be considered when using stable isotopic signatures to investigate intra-specific variations and the timing of life-history events, such as estimating the trophic positions of fish species.

关 键 词：Redfin Culter diet switch stable isotope analyses East Lake Taihu 

分 类 号：S965[农业科学—水产养殖]