Hostname: page-component-cc8bf7c57-fxdwj Total loading time: 0 Render date: 2024-12-11T07:26:55.307Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  01 August 1997

CALUM MACNEIL
Affiliation:
School of Biology and Biochemistry, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland
JAIMIE T. A. DICK
Affiliation:
School of Biology and Biochemistry, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland
ROBERT W. ELWOOD
Affiliation:
School of Biology and Biochemistry, The Queen's University of Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland
Get access

Abstract

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

Type
Review Article
Copyright
Cambridge Philosophical Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)