The diet of ruffe Gymnocephalus cernuus (L.) in northern lakes: new insights from stable isotope analyses

Authors: Tarvainen; Vuorio; Sarvala

Source: Journal of Fish Biology, Volume 72, Number 7, May 2008 , pp. 1720-1735(16)

Publisher: Wiley-Blackwell

Buy & download fulltext article:

OR

Price: $48.00 plus tax (Refund Policy)

Abstract:

The diet of ruffe Gymnocephalus cernuus was studied in two native populations in lakes of different productivity in south-west Finland using both traditional stomach content analyses and stable isotopes. According to stomach content analyses, chironomids were the most important prey type in both lakes and the diversity of the other prey reflected the zoobenthos community in the lake. Stable isotope analyses of carbon and nitrogen showed distinctive lake-specific and total length (LT)-related patterns in both 13C and 15N values, which could not be explained solely with diet changes. In the large mesotrophic Pyhäjärvi, both 13C and 15N isotopes became slightly enriched with increasing ruffe LT, although stomach contents analyses did not suggest any diet change in larger ruffe. In the hypereutrophic Köyliönjärvi, the carbon isotope signatures of ruffe especially showed wide variation (−33·5 to −24·1‰), which was probably due to variable consumption of prey items with highly negative carbon isotope signatures. Overall, this study emphasizes that the interpretation of stable isotope results requires extensive background data of the system and that even then the diet composition of a consumer may be very difficult to define due to large variation in the signatures.

Keywords: invertebrates; ruffe; stable isotopes; stomach content analysis

Document Type: Regular Paper

DOI: http://dx.doi.org/10.1111/j.1095-8649.2008.01847.x

Affiliations: Section of Ecology, Department of Biology, FI-20014 University of Turku, Finland

Publication date: May 1, 2008

Related content

Tools

Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page