Changes in feeding selectivity of freshwater invertebrates across a natural thermal gradient

作     者：Timothy A. C. GORDON Joana NETO-CEREJEIRA Paula C. FUREY Eoin J. O'GORMAN 

作者机构：Imperial College London Silwood Park Campus Buckhurst Road Ascot Berkshire SL5 7PY UK Biosciences College of Life and Environmental Sciences University of Exeter Stocker Road Exeter EX4 4QD UK Department of Biology Saint Catherine University St Paul MN 55105 USA 

出 版 物：《Current Zoology》 (动物学报（英文版）)

年 卷 期：2018年第64卷第2期

页      面：231-242页

核心收录：

学科分类：0710[理学-生物学] 082802[工学-农业水土工程] 07[理学] 08[工学] 0828[工学-农业工程] 071002[理学-动物学] 

基　　金：funded by NERC Imperial College London’s MRes in Ecology, Evolution & Conservation 

主　　题：climate change global warming diet Lymnaea peregra Simuliidae Chironomidae 

摘      要：Environmental warming places physiological constraints on organisms, which may be mitigated by their feeding behavior. Theory predicts that consumers should increase their feeding selectivity for more energetically valuable resources in warmer environments to offset the disproportionate increase in metabolic demand relative to ingestion rate. This may also result in a change in feeding strategy or a shift towards a more specialist diet. This study used a natural warming experiment to investigate temperature effects on the feeding selectivity of three freshwater invertebrate grazers： the snail Radix balthica, the blackfly larva Simulium aureum, and the midgefly larva Eukiefferiella minor. Chesson＇s Selectivity Index was used to compare the proportional abundance of diatom species in the guts of each invertebrate species with corresponding rock biofilms sampled from streams of different tem- perature. The snails became more selective in warmer streams, choosing high profile epilithic diatoms over other guilds and feeding on a lower diversity of diatom species. The blackfly larvae appeared to switch from active collector gathering of sessile high profile diatoms to more passive filter feeding of motile diatoms in warmer streams. No changes in selectivity were observed for the midgefly larvae, whose diet was representative of resource availability in the environment. These results suggest that key primary consumers in freshwater streams, which constitute a major portion of invertebrate biomass, can change their feeding behavior in warmer waters in a range of different ways. These patterns could potentially lead to fundamental changes in the flow of energy through freshwater food webs.