Feeding preference of Asterias rubens of the inter- and subtidal zone of the Wattenmeer of northern Sylt

Asteroidea are cosmopolitan opportunistic benthic predators and scavengers which can be found from shallow coastal waters to the hadopelagial depth of the open ocean. Naturally, prey items in these different habitats may vary. To elucidate the trophic dynamics of the common starfish Asterias rubens of the Wattenmeer in the north of Sylt at the city of List, we designed two separate food preference experiments. For the first experiment we starved A. rubens for 48 hours and then offered five different prey items: Mytilus edulis and Littorina littorea, with and without epizoic Semibalanus balanoides, and Didemnum coriaceum. For the second experiment we offered M. edulis without epizoic S. balanoides, one specimen being crushed and the other being intact. All experiments were conducted under laboratory conditions with singular specimen of A. rubens. Our results suggest differences in the prey choice of adult and juvenile specimen of A. rubens. The second food preference experiment with crushed and intact M. Mytilus did not yield any results. Our study highlights the challenges of recreating the abiotic conditions of the natural environment of epibenthic species in the laboratory. Ample starvation time is important when conducting food preference experiments with A. rubens.