Vetigastropods generally have small eggs that produce lecithotrophic or nonfeeding larvae. Direct development has evolved in several species. Some brooding species use such features of the shell as the umbilicus or surface sculpture to hold the developing young. Unlike the patellogastropods, many vetigastropods secrete egg envelopes and have glandular pallial structures that produce masses of jelly-coated eggs on the sea bed. Early development may occur in some species within these masses of jelly containing the spawn. Copulatory organs in vetigastropods are often derived from cephalic and tentacular structures. Internal fertilization has evolved in several groups and is especially common in species living near deep-sea vents.
Larger species produce millions of eggs per reproductive season and typically have yearly cycles of spawning. Smaller species produce fewer eggs, but can be gravid and capable of spawning year round. Vetigastropod larvae pass through tro-chophore and veliger stages before settling and undergoing metamorphosis.
Was this article helpful?