Postembryonic Development of the Hydrothermal Vestimentiferan Oasisia alvinae Jones, 1985 (Annelida, Siboglinidae)

Abstract

Allometric growth in post-embryonic development was studied in the hydrothermal vestimentiferan Oasisia alvinae Jones, 1985. In the process of growth, the length of the trunk region increases relative to the total body length from 51 to 83.4%, whereas the relative sizes of the obturacular region, vestimental region, and the opisthosoma decrease. This is connected with a strong development of the trophosome and gonads in the trunk region. It is suggested that the predominant growth of the trunk region during ontogeny is a common pattern for all vestimentiferans. We discuss the differences in body proportions of vestimentiferans that live in hydrothermal vents and vestimentiferans of cold hydrocarbon seeps.