Genetic and ecological differentiation of Daphnia longispina species complex in deep canyon-shaped reservoirs

Species complex of Daphnia longispina comprise the most common taxons of Daphnia living in the vast majority of standing waters in the whole Europe. It consists of species D. galeata, D. longispina and D. cucullata which do hybridize and their microscopic identification is often obscure. We routinely use the allozyme markers or other sophisticated DNA analyses for reliable identification of parental taxons or their potential hybrids. The analysis of spatial heterogeneity and genetic differentiation of Daphnia genus in 11 deep canyon-shaped reservoirs has shown that the most common species is Daphnia galeata. If is D. cucullata also occurring, eventually the hybrids D. galeata x cucullata, they are most often in in upstream end of the reservoir. The opposite pattern was found for D. longispina and its hybrids, which seemed to prefer me talimnetic or hypolimnetic strata in the downstream locations during the day. This spatial differentiation of Daphnia taxa might be related with species –specific adaptations against fist predation.

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Dlouhá, S. – Thielsch, A. – Kraus, R.H.S. – Seďa, J. – Schwenk, K. – Petrusek, A. (2010): Identifying hybridizing taxa within the Daphnia longispina species complex: a comparison of genetic methods and phenotypic approaches. Hydrobiologia, in press.

Vaníčková, I. – Seďa, J. – Petrusek, A. (2010): The stabilizing effect of resting eggs banks of the Daphnia longispina species complex for longitudinal taxon heterogeneity in long and narrow reservoirs. Hydrobiologia, in press.