DIFFERENCES IN MORPHOLOGY, SURVIVAL AND SIZE BETWEEN SELF-FERTILIZED AND CROSS-FERTILIZED LARVAE OF MYTILUS-GALLOPROVINCIALIS

The serendipitous detection of a rare hermaphrodite individual of Mytilus galloprovincialis during the process of spawning in the laboratory enabled self- and cross-fertilization to be achieved. Self-fertilized larvae exhibited significantly higher percentages of morphological abnormality at 3 d, lower survival at 9 d and decreased size at 31 d of age compared with cross-fertilized larvae. These results are discussed in the light of equivocal evidence for inbreeding depression in larvae derived from self-fertilization, full-sib matings and gynogenesis in other bivalves.