1. Aeolid veliger illustration adapted from Alder and Hancock. Adult aeolids have no shell, but the veliger stage in the first fortnight or so of life has one, indicating that these sea slugs evolved from shelled gastropdods.
2. Aeolid veliger illustration adapted from Alder and Hancock. Adult aeolids have no shell, but the veliger stage in the first fortnight or so of life has one, indicating that these sea slugs evolved from shelled gastropdods.

Aeolid veliger illustration adapted from Alder and Hancock. Adult aeolids have no shell, but the veliger stage in the first fortnight or so of life has one, indicating that these sea slugs evolved from shelled gastropdods.