Pink-lipped topshell (Oxystele sinensis)

Larger than the other Oxystele species. Round, blunt-spired shell with fine spiral sculpturing. Dark purple-black above. Aperture with a distinctive pink inner lip.

About 45 mm.

Lives moderately low on the shore, extending down to about 5 meters. Grazes on encrusting algae and microalgae. Together with Oxystele tigrina, it is harvested as a source of food in the Transkei.

Two Oceans: A Guide to the Marine Life of Southern Africa (2007, 2016)

Here, a juvenile pink-lipped topshell can be observed on a much larger one. It is recognizable thanks to its fine outer sculpturing, but more importantly the inner pink lip it display (picture below).

This interesting behaviour, of a topshell climbing on top of another one, might help the smaller specimen to alleviate the negative effects of temperature and desiccation stress during low tide on the rocky shore.