Page 62 - Invasive_Species_2013

Mediterranean invasive species factsheet

MOLLUSCS

Reproduction Shell narrows posteriorly
Common name: Asian date mussel

identification

Scientific Name:
Arcuatula (Musculista) senhousia Greenish colour with
Picture radianting red lines

Key identifying features
Brief history
The two valves are oval, elongated and similar in
shape and size. The surface of the shell is marked
with red lines that look like rays extending toward the
edge. The longest side of the shells is slightly
concave. The shell is shiny and pale olive-green with
purple concentric stripes that sometimes are also
visible inside. Adults can reach up to 3 cm in length
and 1 cm in width.
Reproduction
In the Mediterranean Sea, sperm and eggs are
Field identification signs and habitat
released in the water from September to November.
Arcuatula senhousia occurs on soft, muddy bottoms
It is a species with high fecundity, rapid growth and
of bays and estuaries, preferably in sheltered areas
good dispersal ability, making it a successful invader.
from the intertidal zone down to a depth of 20 m. The Larvae live in the plankton for up to 55 days until
mussels construct a nest of trapped sediment where they settle on the bottom. The Asian date mussel can
many individuals live together. A. senhousia forms reach adult size in only nine months and live for a
dense mats of individuals on the bottom (up to 8,000 maximum of two years. Adults can live for several
individuals per square metre). Males and females are days out of the water; they are tolerant of low
not different to the naked eye. salinities, oxygen concentrations and temperatures.

Arcuatula (Musculista) senhousia. Photo. A.N. Cohen, Center
for Research on Aquatic Bioinvasions (CRAB) Arcuatula (Musculista) senhousia. Photo. S. Guerrieri

Monitoring Marine Invasive Species in Mediterranean MPAs: A strategy and practical guide for managers 59