Host Relation Size and Reproduction in the Burrowing BarnacleTrypetesa lampas (Hancock) (Crustacea CirripediaAcrothoracica)

摘要

The aim of thisstudy is to investigate the population biology of the burrowing barnacle s, a symbiont of hermit crabs and representing the little known cirripedegroup Acrothoracica. We put special emphasis on the host-barnacle relation andreproduction. A total of 341 hermit crabs from the west coast of Sweden was captured inNovember 2009 and August 2010, and examined for the associated burrowing barnacles. Wefound a mean load of 1.4 per host and an average prevalence of31.4% with no seasonal variation. Male hermit crabs also carried , indicating that does not rely onegg-predation to any substantial degree. The load waspositively related to host size, but otherwise their frequency distribution did not differfrom random. The position of the burrow in the columella of the shell was positivelyassociated with size. Reproduction seems to occur throughoutthe year. We found ovigerous females also in winter, although less frequently than insummer, and no difference in the number of dwarf males between the summer and wintersamples. The data from the present study site deviates in many respects (prevalence,female and male load, reproductive cycle, host relation) from previous studies on this andclosely related acrothoracican species. This emphasizes that a basic lack of knowledgestill exists concerning most aspects of acrothoracican reproduction, life cycles and hostrelation.