ISSN:
1573-5117
Keywords:
predation
;
Corophium arenarium
;
prey escape
;
drift
;
zonation
;
Nereis diversicolor
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In the European Wadden Sea, the nemertine Tetrastemma melanocephalumoccurs together with its prey, the amphipod Corophium arenarium, in the upper intertidal zone. T. melanocephalumleaves the sediment when the tide has receded and captures C. arenarium in its U-shaped burrow. Highest abundances of T. melanocephalumon the sediment surface were found on summer evenings, 2–4 h after high tide, when just a thin film of water was left on the flats. Laboratory Y-maze experiments indicated that gradients of substances produced by C. arenarium in this film of water play a role in tracking the prey. In the field, T. melanocephalum appeared in significantly higher numbers on experimental high density patches of C. arenarium. The amphipod in turn is able to recognize the nemertine. In aquarium experiments, significantly more amphipods escaped from the sediment into the water column when the predator was present. In the field, both predator and prey showed a high mobility by drifting in tidal waters. Benthic abundance maxima of T. melanocephalum and C. arenariumusually did not coincide spatially. It is assumed that the nemertines avoid tidal flats that dry out quickly leaving too little time for prey capture. T. melanocephalum is not able to dig into the sediment, but lives in burrows of Nereis diversicolor. The abundance of this polychaete was inversely related to C. arenarium, presenting a dilemma for T. melanocephalum: the spatial overlap of food and accommodation was rather small.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1003955523468
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