Page 1 - Ecologya_distribution_2006

Verh. Internat. Verein. Limnol. 29 2150-2156 Stuttgart. December 2006

Ecology and distribution of calanoid copepods
in Sicilian inland waters (Italy)

Federico Marrone, Giuseppe Castelli, Rossella Barone and Luigi Naselli-Flores

Introduction Methods

Sicily covers about lloh of Italian territory, but its in- Samples were collected from autumr 2000 to spring
land water bodies store only loh of national freshwa- 2004 in 256 water bodies scattered throughout the Si-
ter resources. This percentage includes the water cilian territory and the small circum-Sicilian islands
stored in about 30 dam reservoirs, which represents a (southern Italy). The survey incorporated both tem-
vital resource for the economy of the island. Its semi- porary (78o1,) and permanent (22oh) lentic water bod-
arid Mediterranean climate lin-rits water availability ies, from small rock pools to large artificial reser-
in summer months. These environments were studied voirs, ranging from sea level up to 1700 m a.s.l. Even
in the last fifteen years pointing out the effect gener- some saline lakes located in the central part of the is-
ated by water-level fluctuations on ecosystem dy- land, as well as abandoned saltworks were investigat-
namics (Nnsallr-FLoRES ed.
2003).
Temporary water bodies represent another signifi- A 200-pm mesh hand net was used to sample
cant water resource on the island. These freshwater along shorelines and through vegetation. Open wa-
ecosystems, especially in dry regions, not only have ters were sampled by means of an 80-pm towing net.
a socio-economical and cultural value that includes
Smallest environments were sampled by collecting
storage of water for use by local pastoral communi-
the water with a flask and concentrating the samples
ties, but contribute to the maintenance of global bio- on a 200-prm mesh sieve. The size of collected sam-
logical diversity through their exclusive and highly ples strictly depended on the dimensions of the water
specialized plant and animal communities. Despite bodies. Attention was paid to collecting samples in
that, Sicilian temporary ponds have often been neg- all the microhabitats present.
lected due to their ephemeral character and are now
Samples were fixed in situ with 4%o buffered
disappearing because of abandonment of traditional
formaldehyde and sorted in laboratory under an Op-
life styles and land agricultural use as well as unsus-
tika dissecting microscope. Calanoid copepods were
tainable land management practices, including per-
identified according to Dussanr (1967 , 1989),
manent flooding and land-filling for agricultural and
ErNsr-E (1993), KrEptR (1978), PExvosrr (1983),
urban developments. A possible strategy to stop this
RnNcn Rcooy (1994) and Srnlln (1984) arrd stored
tendency is increasing the knowledge on the real bi-
in the authors' collection. Individuals were assigned
ological value of these water bodies. To manage this
to three arbitrary classes according to their relative
task, a series of samplings representative of the Sicil-
abundances and absolute dimensions.
ian territory has been carried out (MnnnoNE 2003a,
b, MRRRoNT, Nespllr-Fr-onEs 2004). These data. In each site, conductivity. pH and water tempera-
&
jointly with those present in the literature (Manc;nn- ture were recorded using a Hanna Instruments HI-
rroRA et al. 1982, Calvo et al. 1993), allowed us to 991300 multiprobe. An estimate of the abundance of
organically assess for the first time the consistency of macrophytes and of the water turbidity was assessed
the entomostracan fauna in the island. In this paper for each site by using three arbitrary qualitative class-
we highlight our results concerning the actual knowl- es. Terrestrial coordinates and altitude were recorded
edge on the distribution of calanoid copepods in Sici- with a GPS Magellan 310. Attention was paid to the
ly and atternpt to highli-qht the relationships between geological nature of the substrate and to the land-
this distribution and some ecolosical features of the scape context in which the water bodies occurred.
sampled sites. Canonical correspondence analysis (CCIA) was un-
dertaken using CRNoco 3.1 (run Bneer & VEnooN-
Key words: Calanoida, Sicily, distribution, biogeog- scHor 1995). The method allows the contenlporary
raphy, Canoco use of quantitative and qualitative variables. The sig-
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