Male L. obtusata in air, restrained with aperture facing up. Most species extend from their shell most readily when submerged, but L. obtusata s.s. is more likely to extend when damp and in air.
Sometimes, body parts display poorly when not supported by water, and they may adhere to the shell or each other. But this is not entirely negative; in this picture the penis (1) is adhering to the shell, and in so doing reveals the numerous small mamilliform glands (2), typical of L. obtusata s.s., that are concealed when, normally, the penis is held against the body. This specimen subsequently moved and clearly exposed the short triangular filament that confirmed the identification; see image Dof9 . Patience is needed with this species if examined when live.
Shell height 10.5 mm. Menai Strait, North Wales. September 2016.
Photographic note.
When photographing submerged gastropods, reflection from the water can be avoided by inclining flash units at less than 45º to the surface. Reflections are unavoidable in photographs of damp subjects, such as this, as the curved surfaces reflect at an infinity of angles.
Full account at: 02 Differentiation L. obtusata/L. fabalis
08 Differentiation L. obtusata/L. fabalis
