Common Periwinkle (Littorina littorea)
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| Distribution | Introduction
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Name: Common Periwinkle
Name: Littorina littorea
Phylum or Division:
is 1.6-3.8 cm high ("Littorina
littorea" IUCN). The shell of L. littorea is sharply conical with a pointed apex and
sculpturing. The smooth
shell color ranges from grey-black-brown-red but is generally black or
grey-brown, and is usually patterned
darker spiral lines. The central axis of the shell is typically white
animal is recognizable in its juvenile stages by the transverse black
of the tentacles which are rather flat and broad.
Distribution: L. littorea
can be found along most intertidal rocky coasts of Great
It is also distributed along the coasts of Ireland and on the
eastern Atlantic Coast from Northern
L.littorea can be found within
the rocky coastline, estuaries and marine habitats of Nova
Scotia and New
Brunswick in Canada.
In addition it is also found is similar ecosystems throughout New
England and Mid-Atlantic states.
Introduction: L. littorea
was introduced from Europe it was first
reported in Canada
in 1840. During the increase in shipping
in the 19th century the gastropod spread to the United
species reached the coast of Maine in 1870 and by 1888 it reached as
far south as Cape May, New Jersey ("Littorina
Introduction: L. littorea
was accidentally brought from Europe to Canada through ballast water of
ships. A second possibility is that the species was brought
over for food as it is eaten in many parts of Europe. From
there L. littorea spread
south to the United States through the shipping business. Within
18 years the species spread through the whole New England coast and in
a second introduction into Maryland and Delaware, L.littorea spread throughout the
whole Atlantic coast of those states ("Littorina
littorea" Clark). Few reports have noted its spread south
Reason(s) Why it has
Due to the ability of L. littorea to exist
in a variety of conditions it has been able to spread along rocky
coastlines at a fast rate. L.
littorea is inhabits all except the most exposed
from the upper shore into the sub littoral zones. In
sheltered conditions it can also be
found in sandy or muddy habitats such as estuaries and mud flats. The
is also fairly tolerant of brackish water.
The preferential food for L.
littorea is highly available along most of the Northeastern
coast of North America enabling this
Role: L. littorea is an
important part of the rocky intertidal ecosystem. L.
littorea is a dominant herbivore and an important macro-algal
grazer that competes with many
local species in both New England and Canada ("Littorina littorea"
IUCN). Once they have come out
of the water column as adults they are significant grazers upon
also trying to establish in the zone. It
feeds on Enteromorpha,
Ulva, and Porphyra and also diatoms.
Benefit(s): L. littorea has been
shown to reduce the growth of the non-native Ulva lactuca
from dominating the intertidal zone in Massachusetts. By doing so, native species of seaweed have been able
to out compete U. lactuca for
space and nutrients. It
has also been suggested that L. littorea
can be a highly suitable bio-indicator species for contamination of the
environment ("Littorina littorea"
IUCN). Many behavioral changes of this species have been
correlated with changes in trace elements and compounds in
the water. L.littorea can be
used to detect such changes that might threaten other species,
Threat(s): L. littorea has drastically altered the New England
community structure by allowing slow growing Chondrus crispus
overtake faster growing green algal species ("Littorina littorea" IUCN). By feeding off of other species of seaweed L.littorea allows the growth of C.crispus when it would otherwise
could not become dominant. While not common, some locations where
L.littorea are present have
experienced a complete transfer of multiple algal species to a
monoculture of C. crispus.
The invasion of L .littorea has
also brought the marine black spot disease. This disease
caused by a parasitic worm results in black spots on infected fish, and
has caused a lot of damage to local fisheries. L.littorea acts as the first host
for the disease, which it transfered when the infected individual is
eaten by fish. This disease also affects birds.
Level Diagnosis: While L. littorea
has spread widely along the coasts of North America
species should be considered medium priority.
L. littorea has become an
important part in the ecology of rocky intertidal shores.
Through a rapid increase in numbers L. littorea
has out competed many
similar gastropods for space, a limited resource in the intertidal zone. L. littorea has
allowed for the growth of Chondrus crispus but L. littorea has
also benefit the
ecosystem by controlling the introduced Ulva
There have been few methods of control
for L. littorea. Current eradication
ideas for a similar species Littorina saxatilis
in the San Francisco Bay
involve biocides, manual eradication and the use of
bio-controls. However, little has been done in the way of eradication
research for the removal of L. littorea.
A main point of concern involves the study of ways to avoid a
“Littorina littorea" Clark
littorea” IUCN Global Invasive
Species Database http://www.issg.org
Periwinkle Littorina littorea” The
Marine Life Information Network of Britain and Ireland.
(2) Clark University
(3) Jon Davies/JNCC (published on
Last Edited: November 23, 2004