Importance of fungi in the diet of Gammarus pulex and Asellus aquaticus I: feeding strategies.
The importance of fungi in the trophic biology of the freshwater detritivores Gammarus pulex and Asellus aquaticus was investigated. Inspection of leaves used in feeding trials indicated that whereas A. aquaticus scrapes at the leaf surface, G. pulex bites through the leaf material. Both species discriminated between fungal mycelia, fungally colonized and uncolonized leaf material but, although A. aquaticus selectively consumed fungal mycelia, G. pulex fed preferentially on leaf material. Fungi appear to be an important food source for A. aquaticus and selection of food material was positively correlated with fungal biomass. In contrast, for G. pulex, fungi appear to be more important as modifiers of leaf material. However, no significant correlations were found between food preference and any of the leaf modifications measured.
Departamento de Zoologia, Universidade de Coimbra, 3049, Coimbra Codex, Portugal.
M A S
MA
Graça
Department of Animal and Plant Sciences, University of Sheffield, S10 2TN, Sheffield, UK.
L
L
Maltby
Department of Animal and Plant Sciences, University of Sheffield, S10 2TN, Sheffield, UK.
P
P
Calow
Asellus aquaticus; Detritivores; Food choices; Gammarus pulex; Niche breadth; Trophic biology