VARIATION IN THE OCCURRENCE OF ABNORMAL EMBRYOS IN FEMALES OF THE INTERTIDAL GASTROPOD LITTORINA SAXATILIS OLIVI

Abstract

The incidence of abnormally developed embryos within the brood-pouch of female L. saxatilis was very variable, ranging from 0–100% of embryos being abnormal. A minor part of the total variation was attributed to between-shore variaion, while 82% reflected within-sample differences between females. Possible factors responsible for the variation in embryo abnormality shown by this and other investigations, are discussed and it is concluded that genetic rather than non-genetic factors are important.