Contrasting life history strategies in a phylogenetically diverse community of freshwater amphipods (Crustacea: Malacostraca)
Abstract
Differences in life histories are commonly exhibited within ecological communities, especially amongspecies that display increased variations in body size and morphology and are phylogenetically dis-tant. To examine the relationship between morphological dissimilarity and life history divergence, weinvestigated three morphologically distinct and distantly related species of freshwater amphipods thatco-occur throughout the Danube lowlands - Gammarus balcanicus dacicus, Niphargus valachicus andSynurella ambulans - by collecting monthly samples during a one-year period.
Results revealed thatthe studied species differ significantly with respect to fecundity, size at maturity, number of generationsper year, duration and timing of the reproductive period and egg volume. Despite some overlap, eachspecies possesses a unique combination of traits, supporting the hypothesis that life history variationwithin freshwater amphipod communities can reflect dissimilarities regarding body size, morphologyand evolutionary relationships.
However, it is not yet clear which of these factors has the most significantcontribution to life history divergence.