Feeding guilds in Collembola based on digestive enzymes

Abstract

The digestion ability of 20 species of Collembola sampled from nutrient-poor moist peat meadows was determined. The activity of three carbohydrases was measured, i.e. trehalase, cellulase and chitinase. Species were classified in feeding guilds based on the presence or absence of enzymatic activity. The majority of the samples analysed showed trehalase and cellulase activity, and indicate that Collembola commonly have the ability to digest cell walls of plants and algae, and the contents of fungal hyphae. Most of the species examined had chitinase activity, and are able to digest fungal cell walls. Based on the results, four feeding guilds were distinguished, i.e. herbo-fungivorous grazers (nine species), fungivorous grazers (two species), opportunistic herbofungivores (one species) and omnivore (one species). Five species could not be classified due to low number of samples. One more feeding guild was indicated if the levels of enzymatic activity within species were taken into account, i.e. fungivorous browsers. The results show that most species have the ability to digest the food items reported from gut content analyses. Between species, significant difference in specific enzymatic activity was recorded. These findings suggest that, together with information on feeding guilds, under field conditions the various species in the community differed in their food choice. It is hypothesised that a relationship exists between the mouthpart morphology of Collembola species and specific carbohydrase activity.