Littorina planaxis
Periwinkles are one organism in the intertidal zone that is able
to survive long-term air exposure. In fact, periwinkles cannot
withstand prolonged emersion in seawater. They protect themselve
by clamping down tightly against the rock, sealing their shell with
a glue-like mucus. They are mostly active at night when the
humidity is high. As periwinkles glide along rocks, they ělickî
the surface to scrape off microscopic organisms. The main predators
of these snails are shorebirds.
Habitat/Range: Periwinkles can be found on pilings, docks, bays,
and in rocky areas from Alaska to Baja California.