These "periwinkles" as they are called were found all over the rocky coasts of Koh Kood, clamped on to the sides of rocks.
According to Wikipedia:
The common periwinkle or winkle, Littorina littorea, is a species of small edible sea snail, a marine gastropod mollusc that has gills and an operculum, and is classified within the family Littorinidae, the periwinkles.
This is a robust intertidal species with a dark and sometimes banded shell. It...more »
Filename: Common Periwinkle.jpg
Copyright Sutton Photos