The settlement ofPomatoceros lamarckiilarvae (Polychaeta: Sabellida : Serpulidae): A laboratory study

Initial experiments showed consistently that substrata biofilmed under static conditions with filtered seawater containing an algal mixture and adult Pomatoceros lamarckii (intact animals in their tubes attached to rocks) were the most attractive to settling P. lamarckii larvae. Surfaces became more favourable to settling larvae with increasing biofilming time. The adult tubes did not release a chemical settlement stimulus, as shown by an extremely low settlement (0.1%) on the test surfaces. However, treatment of 3 w‐biofilmed substrata with a seawater leachate of whole adult P. lamarckii freed from their tubes induced > 60% larval settlement. These findings demonstrate that P. lamarckii larval settlement is facilitated by biofilms coupled with an adsorbed chemical cue(s) emanating from juvenile and adult worms.