Differences in feeding behaviour among Chironomus species revealed by measurements of sulphur stable isotopes and cadmium in larvae. (3rd October 2013)

• Record Type: Journal Article
• Authors: Proulx, Isabelle; Hare, Landis
• Is Part Of: Freshwater biology. Volume 59:Number 1(2014:Jan.)
• Page Start: 73
• Page End: 86
• Publication Date: 2013-10-03
• Subjects: Freshwater biology -- Periodicals; Biologie d'eau douce -- Périodiques; 577.605
• DOI: 10.1111/fwb.12247
• Languages: English
• ISSNs: 0046-5070

Abstract

<abstract abstract-type="main" id="fwb12247-abs-0001"> <title>Summary</title> <p> <list id="fwb12247-list-0001" list-type="order"> <list-item> <p>We set out to determine the feeding behaviours of 15 <italic>Chironomus</italic> species collected from 16 boreal forest lakes by measuring cadmium (Cd) and stable isotopes of carbon (C), nitrogen (N) and sulphur (S) in larvae.</p> </list-item> <list-item> <p>Measurements of S stable isotopes and Cd discriminated between <italic>Chironomus</italic> species that feed mainly on oxic particles from those that feed mainly on anoxic particles. Our results suggest that <italic>C. dilutus</italic>, <italic> C. entis</italic>, <italic> C. plumosus</italic> and <italic>C. staegeri</italic> feed mainly on oxic particles (in the water column, in sediment or both), whereas <italic>C. anthracinus</italic>, <italic> C. bifurcatus</italic>, <italic> C. cucini</italic>, <italic> C. decorus</italic>‐group sp. 2, <italic>C. harpi</italic>, <italic> C</italic>. nr. <italic>atroviridis</italic> (sp. 2i), <italic>C. ochreatus</italic>, <italic> C</italic>. spp. NAI‐NAIII and <italic>C. 'tigris'</italic> feed mainly on anoxic sediments.</p> </list-item> <list-item> <p>In our study lakes, larval C isotopic signatures were relatively high, which suggests that they feed little on methanotrophic bacteria. Although larval C and N signatures differed between some sympatric <italic>Chironomus</italic> species, these differences were not consistent among lakes. The absence of a trend among lakes suggests that lake‐specific factors determine larval C and N signatures.</p> </list-item> <list-item> <p>Differences in feeding habits and Cd concentrations among sympatric (cohabiting) <italic>Chironomus</italic> species suggest that pooling them in ecological, palaeolimnological or ecotoxicological studies could obscure trends in nature, thereby limiting their use as monitors of climate change or pollution.</p> </list-item> </list> </p> </abstract>