Unlike marine prosobranch gastropods, which defecate into a mantle cavity that is cleared by water currents, M. myosotis has a rectum that opens to the exterior through an anus in a folded part of the mantle-collar in the adapical angle of the aperture (1), near to, but separate from, the pneumostome (2) so that faeces are expelled without fouling the respiratory mantle-cavity.
3: mantle collar.
4: side of body.
5: sole of foot.
27 Myosotella myosotis. Adapical angle of aperture. Salting on Dee Estuary, Cheshire, England. May 2018. Photographed in air.
