Distribution in scandinavian waters
Maximum length: 2 cm.
Appearance: The shell
can vary greatly in colour, pattern and form. The soft
parts are uncoloured to light black. Every tentacle has one
or two dark lateral stripes. Compare with the common
Depth: The rough periwinkle lives quite high
up on the beach. It is enough that it gets occasionally wettened
by the waves and sea spray.
Environment: Lives on both soft and hard bottoms. The species
is common on rocks and cliffs
on most beaches. They are seldom found on sand or seaweed, but there
is a form that lives on seaweed
in protected bays and beaches. Empty shells from this species are
commonly found on beaches.
Misc: The young develope
completely inside the mother: out creeps a 0,5 mm large copy of
Classification: The rough periwinkle is part of the
periwinkle group under the molluscs.