Evidence of amictic reproduction in the brittle-star Ophiomyxa brevirima

Abstract

Ophiomyxa brevirima is a direct-developing species of brittle-star found around the coast of New Zealand. The mode of reproduction of this ophiuroid was studied using isozyme electrophoresis of mother and brooded offspring. Multi-locus assessment of the genotypes of 35 adult females and their brooded offspring was undertaken. A minimum of 45% of broods assessed showed evidence of amictic reproduction, with all offspring in these broods possessing genotypes that were identical to the genotype of their heterozygous mother. In most other broods there was evidence of segregation. These observations are interpreted as evidence of both sexual and asexual reproduction in this ophiuroid species.