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Vol. 53, 2014
Pseudodiaptomus marinus Sato, 1913, a new invasive
copepod in Lake Faro (Sicily): observations on the swimming behaviour
and the sex-dependent responses to food
Luciana
Sabia1,2,4*, Marco Uttieri2, François G Schmitt3,
Giacomo Zagami1, Enrico Zambianchi2 and Sami
Souissi3
1Department
of Biological and Environmental Sciences, University of Messina, V.le
F. Stagno d’Alcontres,31, S. Agata-Messina 98166, Italy
2Department
of Science and Technologies, University of Naples ‘Parthenope’, Centro
Direzionale di Napoli, Isola C4, Napoli 80143, Italy
3Laboratoire d’Océanologie et de Géosciences UMR CNRS
8187 LOG, Université Lille 1, Station Marine 28 avenue Foch, Wimereux
62930, France
4Present address: Department of Sciences and
Technologies, University of Naples ‘Parthenope’, Centro Direzionale di
Napoli – Isola C4, Napoli 80143, Italy
Abstract
Background: The calanoid copepod Pseudodiaptomus marinus Sato, 1913 is an
estuarine-coastal species, living in shallow eutrophic inshore waters.
It is native of the Indo-Pacific region, but in the last 50 years, it
has successfully colonized new areas worldwide. P. marinus, first recorded in Lake
Faro (Messina, Italy) in October 2008, is now a stable component of the
zooplankton assemblage of the lake. By means of video recordings, for
the first time, the swimming behaviour of males and non-ovigerous and
ovigerous females of P. marinus
has been studied. The individuals were filmed in the presence and
absence of food to evaluate how the presence of prey might affect the
swimming behaviour.
Results: The swimming motion showed marked
sex-dependent features and responses to the presence of food.
Mechanisms through which behaviour might influence the outcome of a new
colonization were analysed. The behaviour of P. marinus was then compared with
that of the congeneric Pseudodiaptomus
annandalei showing the
typical behaviour displayed by the representatives of the genus Pseudodiaptomus of living in
proximity of the bottom.
Conclusions: Environmental and
hydrological conditions in Lake Faro have likely provided the newly
introduced P. marinus a
suitable environment for settling, although normally the presence of an
anoxic deep layer would be detrimental for a demersal species. In this
case, the plasticity in the behaviour of P. marinus enhanced its capacity
for colonising new environments. Switching from demersal to pelagic
habitat or being fully planktonic allowed it to express its large
individual variability in motion strategies and thus to successfully
colonize the lake.
Key words: Pseudodiaptomus marinus; Swimming behaviour;
Invasive species; Sex-dependent behaviour.
*Correspondence: E-mail: luciana.sabia@uniparthenope.it
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