THE TROPHIC ECOLOGY OF FRESHWATER GAMMARUS SPP. (CRUSTACEA:AMPHIPODA): PROBLEMS AND PERSPECTIVES CONCERNING THE FUNCTIONAL FEEDING GROUP CONCEPT

• DOI: 10.1111/j.1469-185x.1997.tb00017.x
• Publication Date: 2010-08-18T09:59:38Z
• Authors: CALUM MACNEIL; JAIMIE T. A. DICK; ROBERT W. ELWOOD
• Keywords: Gammarus; Cannibalism; Trophic cascade; Intraguild predation; Gammarus pulex

ABSTRACT Gammarus spp. are widespread throughout a diverse range of freshwater habitats and can be the dominant part many benthic macroinvertebrate assemblages, in terms both numbers and/or biomass. Although vast majority studies have emphasized herbivorous nature their ‘shredder’ functional feeding group (FFG) classification, we show that far wider food base is exploited than has been previously acknowledged. This ‘plasticity’ as herbivore/predator linked to success persisting colonizing/invading disturbance‐prone ecosystems. Intraguild predation cannibalism more common realized. behaviour appears causal mechanism amphipod species replacements. Additionally, major predators other members community. Furthermore, while fish on spp., illustrate how this fish: amphipod, predator: prey interaction may two‐way process, with themselves preying upon juvenile wounded/trapped fish. We urge new realism adopted towards trophic ecology role established FFG assumptions feeder questioned critically.