Waterbird-mediated passive dispersal of river shrimp Athyaephyra desmaresti

Abstract

The river shrimp Athyaephyra desmaresti is a Mediterranean species which in recent years expanded its distribution, colonizing rivers of central Europe. The purpose of this study was to investigate the possibility of passive external dispersal of the river shrimp Athyaephyra desmaresti by waterfowl. We performed experiments testing shrimp desiccation survival, probability of attachment to waterfowl, and probability of successful transport. We found that in the laboratory 10% of the river shrimps can survive out of water for up to 90.1 min, but this period was reduced to 18.5 min under simulated bird flight conditions. Two different outdoor experiments simulating bird flight conditions indicated a 50% probability of successful transport on flight distances over 15 km. Our results using dead ducks show evidence that small, large or ovigerous river shrimps can attach to and be transported by ducks and that this capacity is affected by water depth. This study demonstrated that waterbird-mediated passive dispersal of river shrimps can occur and may be important for genetic flows between populations and for the colonization of new sites.