The population dynamics and feeding preferences of Bursatella leachii (Opisthobranchia: Anaspidea) in northeast Queensland, Australia

Abstract

Sea hares (Opisthobranchi: Anaspidea) have long been known to form dense aggregations in shallow marine habitats. However, there have been few attempts to document the dynamics and causes of these aggregations. The present report investigates the population dynamics of Bursatella leachii found in association vith a cyanobacterial bloom in tropical north Queensland, Australia. The aggregation was fuelled by a continual source of recruits and in laboratory testing, this population preferred a green alga to its prey item in the field, the cyanobacterium, Calothrix crustacea. Therfore, B. leachii has the ability to continually recruit in large numbers to seagrass beds in order to exploit an abundant but less preferred food resource.