3D-interactive microanatomy of Ventsia tricarinata Warén & Bouchet, 1993 (Vetigastropoda: Seguenzioidea) from Pacific hydrothermal vents

Abstract

The microanatomy of Ventsia tricarinata Warén & Bouchet, 1993, a small coiled 'skeneimorph' gastropod from Pacific hydrothermal vents, is described based on computer-aided reconstructions of semithin section series and visualized by interactive 3D-modelling. This is the most complete account of the anatomy and histology of a seguenzioid vetigastropod presented to date, although details of the male genital system could not be detected. This species was placed originally in the Skeneidae (Trochoidea), but molecular data subsequently suggested a basal seguenzioidean position. The latter hypothesis is supported herein by morphological data, in particular by the conditions of the right neck (with two tentacles), the epipodium (with separated epipodial sense organs) and the bipartite seminal receptacle with concentric arrangement of sperm in its posterior part on the left side of the mantle roof.