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Mediterranean invasive species factsheet

Reproduction Similar species
L. lallemandii is able to reproduce sexually and The species can easily be confused in the field with
asexually, and both forms have the same other red filamentous algal species.
appearance. It reproduces sexually only during
summer and autumn (from April to October), while Brief history of its introduction and
its vegetative reproductive activity occurs throughout pathways
the year, with minimal growth during late autumn
Lophocladia lallemandii is one of the numerous
and winter. Moreover, besides reproducing
macroalgal species introduced into the
vegetatively through spore dispersal, it can spread
Mediterranean probably from the Red Sea via the
by fragmentation: Lophocladia is easily broken and
Suez Canal. It has now spread throughout most of
free-floating filaments produce small, disc-like
the Mediterranean, with the exception of Moroccan
holdfasts that are able to attach to a large variety of
waters and the north-western Mediterranean.
floating substrates.
Ecological impacts
Due to its high invasive potential, L. lallemandii is
able to cover most kinds of substrate, giving the
benthic seascape a homogeneous appearance. The
behaviour of L. lallemandii seems to be very
aggressive, especially when colonizing Posidonia
oceanica meadows, as it forms such extensive,
dense mats within the meadows that it causes a
major decrease in seagrass density and growth that
can lead to the death of the plants. It also affects the
invertebrate community living on P. oceanica leaves
by outcompeting it for space.

Economic impacts
Unknown.

Management options

Because it can reproduce and spread so fast, it is
impossible to eradicate L. lallemandii populations, at
least by manual methods. The species might be
controlled most efficiently and effectively, and at the
lowest cost, early in the invasive process.

Further reading

Ballesteros, E., Cebrian, E., Alcoverro, T., 2007. Mortality
of shoots of Posidonia oceanica following meadow
invasion by the red alga Lophocladia lallemandii. Bot. Mar.
50, 8–13.
Cebrian E, Ballesteros E., 2010. Invasion of Mediterranean
benthic assemblages by red alga Lophocladia lallemandii
(Montagne) F. Schmitz: depth-related temporal variability in
biomass and phenology. Aquat Bot. 92, 81–85.
Deudero S., et al, 2010. Interaction between the invasive Drawings: Juan Varela
macroalga Lophocladia lallemandii and the bryozoan
Reteporella grimaldii at seagrass meadows: density and
physiological responses. Biological invasions Vol. 12, No 1,
Algae with reproductive organs, tetraspores and carpospores.
Photos: E. Cebrian 41-52.

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