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Mediterranean invasive species factsheet

MOLLUSCS

Reproduction Common name: Slipper limpet

Commonly found in
large internal aperture
stacks Smooth oval shell with a
identification

Scientific Name:
Crepidula fornicata
Picture

Key identifying features
The slipper limpet is a snail with a smooth, oval-
shaped shell that shows irregular concentric growth Brief history
lines. It is white, cream, yellow or pinkish with
brown or red veins or spots. Inside it has a thin
lamina extending halfway across the shell aperture.
In the Mediterranean, slipper limpets can attain
sizes of up to 3 cm. They are commonly found
attached one on top of the other forming stacks of
2–20 animals, with the largest at the base attached Reproduction
Crepidula fornicata is a hermaphrodite, changing
firmly to an object with its muscular foot.
sex during its life. Females brood eggs that are
internally fertilized by males that stack on top of
Field identification signs and them. Usually a few large females are on the
habitat bottom and several smaller males stack on top.

This species is a filter-feeder occurring within Eggs contained in capsules hatch into planktonic
sheltered coastal bays and estuaries, sometimes in larvae which, after a short larval period, settle on
low-salinity environments. It settles on other shells hard substrates in response to a water-soluble
or hard substrates on mud and sand-gravel chemical secreted by adults. They attach to a stack
bottoms from lowest water down to depths of about and reach maturity as young males in about two
30 m. It can also survive prolonged periods out of months, subsequently undergoing a sex change to
the water, especially if exposed to freezing become females. Occasionally solitary (not stack-
temperatures, and polluted waters where turbidity is forming) individuals occur, in which case they self-
particularly high. fertilize.

Crepidula fornicata. Photo: C. Scouppe

Monitoring Marine Invasive Species in Mediterranean MPAs: A strategy and practical guide for managers 69