A matter of perception: The influence of waterborne signals from fish and conspecifics on the feeding related behavior of Alitta virens (Sars)

The present study compares the influence of signals released from fish (common sole, Solea solea L.) and conspecifics on the feeding behavior of the ragworm Alitta virens (Sars) (formerly known as Nereis virens (Sars). Experimental tanks stocked with ragworms were connected to a donor tank by a tube to allow the transfer of water born signal molecules. The donor tanks were stocked with sole and ragworms to create 4 different treatments: “control (blank)”, “ragworms”, “sole” and “sole + ragworms”. All behavioral recordings were made at 19 random days out of a total of 31 feeding days. Video recordings were made each time for 30 minutes starting when first feed entered the tank. All behavioral responses, i.e. latency, numbers and length of ragworms out of burrow were negatively affected when ragworms were exposed to water from “sole + ragworms” donor tanks. When exposed to water from “ragworms” and “sole” donor tanks, the experimental ragworms also reduced their behavioral responses but to a lesser extent than when exposed to the combination of “sole + ragworm” donor tanks. Out-of-burrow activities remained hampered in ragworms exposed to water coming from “sole” and “sole + ragworms” donor tanks at all observation days. Results indicate that signals released by damaged conspecifics and to a lesser extent fish borne cues play an important role in anti-predatory behavior of A. virens.