Contribution of Chemoautotrophic Production to Freshwater Macroinvertebrates in a Headwater Stream Using Multiple Stable Isotopes

✍ Scribed by Hideyuki Doi; Atsushi Takagi; Chitoshi Mizota; Jun-ichi Okano; Shin-ichi Nakano; Eisuke Kikuchi

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 115 KB
• Volume: 91
• Category: Article
• ISSN: 1434-2944
• DOI: 10.1002/iroh.200610898

✦ Synopsis

Abstract

We estimated the food sources of macroinvertebrates using carbon, nitrogen, and sulfur stable isotopes in a headwater stream. Stream food webs, including macroinvertebrates, rely on production from autochthonous and allochthonous photosynthesis. We found that a freshwater grazer, the snail Semisulcospira libertina, may assimilate different food sources, based on stable carbon and nitrogen isotope evidence from snail muscle and the much lighter sulfur isotope signature than those of other associated macroinvertebrates. Previous studies have shown the importance of methanotrophic and sulfur bacteria in reductive environments (clay and organic‐rich sediments) as food sources for macroinvertebrates. Our results show that the production by chemoautotrophic bacteria contributes to the food sources of a snail in a stream. Thus, the chemoautotrophic bacteria are important in the freshwater food webs, even in mostly aerobic habitats. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)