Factors affecting settlement and early post‐settlement survival of the New Zealand abalone <i>Haliotis australis</i>

Abstract

Abstract This paper describes studies on the settlement of the abalone Haliotis australis Gmelin. Ten‐day‐old H. australis larvae had a slower rate of settlement than 5‐day‐old larvae. A high proportion of veliger larvae had the ability to prolong the searching phase of settlement and delay metamorphosis, even over prepared settlement surfaces but radula development continued at a similar rate in both settled and swimming larvae. In any one batch of larvae settlement was slow and asynchronous and post‐settlement survival was low. Light was shown to influence the swimming behaviour of larvae in settlement tanks, with more larvae swimming in the dark than in the light. The implications of these behaviours are discussed in relation to larval and post‐larval energetics and feeding.