Page 4 - Covazzi2002

The first cruise took place between July and August 1983 along the coasts of
Ustica Island, Egadi and Aeolian Archipelagos. A total of 270 grab samples were
collected in 134 stations between 15 and 540 m (station lists and bottom features in
Albertelli et al., 1987); 20 specimens and 13 species were found at Ustica, 111
specimens and 40 species in the Egadi Archipelago and 112 specimens and 35 species
in the Aeolian Archipelago.

The second cruise took place in October 1984 in the Partenopean and Pontine
Archipelagos for a total of 263 grab samples collected in 123 stations between 22 and
152 m depth (Fig. 1). In this case 155 specimens and 34 species were found in the
Pontine Archipelago and 129 specimens and 37 species in the Partenopean one.

Cluster analysis was performed using the software PRIMER on a matrix of
presence/absence transformed data.

Bionomical features of the species considered in this work are reported according
to Pérès & Picard (1964), Febvre-Chevalier (1969), Albertelli & Drago (1976),
Albertelli et al. (1992). Mollusc nomenclature follows Sabelli et al. (1990).

Text abbreviations used in tables and figures are:
Egadi Archipelago: MA = Marettimo, FA = Favignana, LE = Levanzo, GR = Grande;
Aeolian Archipelago: LI = Lipari, SA = Salina, VU = Vulcano, PN = Panarea, ST =
Stromboli, FI = Filicudi; Partenopean Arcipelago: PR = Procida, CA = Capri, IS =
Ischia; Pontine Arcipelago: VE = Ventotene, SS = Santo Stefano, PO = Ponza, PA =
Palmarola, ZA = Zannone; Ustica Island = US.

3. RESULTS AND DISCUSSION

In Ustica Island (Table 1) 20 specimens, belonging to 13 species, were found. Sea
bottoms showed a coarse, detritic sediment until 130 m, followed thereafter by a muddy
mixed sediment. On a total of 26 stations investigated, only 10 had living molluscs.

Tab. 1 - Species list, bionomical features and total number of specimens (TNS) of Ustica Island.
In brackish is reported the number of stations investigated around the Island were molluscs were found.

Species list Bionomical TNS

features (10)

Chlamys sp. 1
1
Cuspidaria cuspidata (Olivi) Sab.toll. 1
1
Digitaria digitaria (L.) 2
6
Diodora italica (Defrance) AP 1
1
Emarginella huzardii (Payraudeau) SD 1
1
Lepidopleurus (P.) africanus Nierstrasz DC 1
2
Mactra stultorum (L.) SFBC excl 1

Modiolula phaseolina (Philippi) DC excl

Palliolum incomparabile (Risso)

Sepiola sp

Tellina balaustina L. Mixt

Tellina crassa Pennant SGCF excl

Thracia papyracea (Poli) SFBC excl

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