Population Structure and Reproduction of the Fissiparous Seastar, Linckia columbiae Gray, on Santa Catalina Island, California

Abstract

Linckia columbiae is a sexual species that also reproduces asexually by ray autotomy. Seventy percent of L. columbiae surveyed at the Catalina Marine Science Center Marine Life Refuge, Santa Catalina Island were regenerating autotomized rays. Autotomy occurred throughout the year with the highest incidence in late summer. The incidence of autotomy correlates with growth, but not gender or depth. Regeneration experiments suggest that 3 yr, or longer, may be required for a single ray to reach the adult stage. Gametogenesis was generally confined to non-regenerating rays. Oocyte production was low and spawning occurred in late summer. Lacking evidence of recent larval recruitment at the study site, population densities and morphometric features of L. columbiae are best explained by continuous asexual reproduction.