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represented not only by Acartia negligens, A. clausi and A. danae, but also by A.
adriatica.
Fig. 4 - Vertical pattern of copepod diversity (Hƍ) and abundance (ind m-3).
The occurrence of this species, restricted to neritic area near Sicilian shorelines, is
important because this is the first record of A. adriatica in the Tyrrhenian Sea. The
coastal area are characterized by the highest abundances due to the strong dominance of
one or few autumnal coastal species, such as Clausocalanus furcatus and Temora
stylifera (Mazzocchi & Ribera d’Alcalà, 1995). Copepod population densities are lower
and more homogenously distributed in the pelagic area and between the islands. In the
pelagic stations, surface copepod assemblage is not only constituted by typical coastal
species, but also epipelagic species, such as C. vanus, C. jobei and C. arcuicornis. The
gradual change in copepod species composition from inshore to offshore waters was
sustained by Scotto di Carlo et al. (1984). Therefore, an abundance decrease and a
corresponding increase of diversity levels were observed. Vertical abundance and
diversity index patterns of copepod species in the Egadi Islands, are in according to the
most characteristic copepod spatial distribution in the Mediterranean Sea (Scotto di
Carlo et al., 1984) and are primarily affected by the depth. Surface layers present
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