文章基本信息

标题：Comparing isotope signatures of prey fish: does gut removal affect δ 13 C or δ 15 N?
本地全文：下载
作者：Mark J. Fincel ; Justin A. VanDeHey ; Andrew Wuestewald 等
期刊名称：Journal of Freshwater Ecology
印刷版ISSN：0270-5060
电子版ISSN：2156-6941
出版年度：2012
卷号：27
期号：1
页码：55-62
DOI：10.1080/02705060.2011.604984
出版社：Taylor & Francis
摘要：Stable isotope analysis is a quick and inexpensive method to monitor the effects of food web changes on aquatic communities. Traditionally, whole specimens have been used when determining isotope composition of prey fish or age-0 recreational fishes. However, gut contents of prey fish could potentially alter isotope composition of the specimen, especially when recent foraging has taken place or when the gut contains non-assimilated material that would normally pass through fishes undigested. To assess the impacts of gut content on prey fish isotope signatures, we examined the differences in isotopic variation of five prey fish species using whole fish, whole fish with the gut contents removed, and dorsal muscle only. We found significant differences in both δ 15 N and δ 13 C between the three tissue treatments. In most cases, muscle tissue was enriched compared to whole specimens or gut-removed specimens. Moreover, differences in mean δ 15 N within a species were up to 2‰ among treatments. This would result in a change of over half a trophic position (TP) based on a 3.4‰ increase per trophic level. However, there were no apparent relationships between tissue isotope values in fish with increased gut fullness (more prey tissue present). We suggest that muscle tissue should be used as the standard tissue for determining isotope composition of prey fish or age-0 recreational fishes, especially when determining enrichment for mixing models, calculating TP, or constructing aquatic food webs.
关键词：stable isotope analysis; rainbow smelt; gizzard shad; yellow perch; white bass; spottail shiner