BEHAVIORAL SPECIFICITY AND THE INDUCTION OF HOST RECOGNITION IN A SYMBIOTIC POLYCHETE

¹ Department of Biological Sciences, University of California, Santa Barbara, California 93106

1. Several populations of the symbiotic polychaete Arctonoe pulchra were examined with regard to the ability of these worms to detect chemical signals emanating from their hosts. Four of the five experimental populations exhibited chemotactic responses which can be interpreted as host recognition.

2. The host recognition responses were for the most part very specific in that worms consistently chose their original host when presented effluents from a variety of organisms in a Y-maze choice apparatus.

3. The specificity of these chemotactic responses could be affected by the previous experience of individual worms. That is, worms could be conditioned to respond to an organism which previously was unattractive to them.

4. The mechanisms involved in effecting this modification of behavior are not clear. However, the results of this study indicate a heretofore unknown behavioral capability among these polychaetes.