Preprint volume - SIBM

Pre-print Volume - Oral presentations
Topic 2: MARINE ORGANISMS AND ECOSYSTEMS AS MODEL SYSTEMS
cornucopiae finally shows minimum densities in the coldest period, with a minimum of
1840 polyps m -2 ±467.55 SE in February, and greater abundance in summer, with an
August peak of 29620 polyps m -2 ±630.40 SE. Polyps reproduce from April to June
with the 80% of fertile polyps in spring. The cnidarian gut content analyses revealed
that the three considered species feed on Mytilus galloprovincialis pediveligers. In
particular E. racemosum intensively feed on these and other meroplanktonic larvae
showing an estimated predation rate of 2,400,000 prey items m -2 day -1 (Di Camillo et
al., in press).
Fig. 1 - Trends of density and % coverage of four benthic species of the Conero Promontory. A) T.
anhelans; B) A. aurita; C) E. racemosum; D) C. cornucopiae. The dotted line shows the monthly
average sea temperatures during the study periods (http://www.mareografico.it).
Andamenti di densità e % di ricoprimento di quattro specie bentoniche del Promontorio del Conero.
A) T. anhelans; B) A. aurita; C) E. racemosum; D) C. cornucopiae. La linea tratteggiata mostra
l’andamento delle medie mensili della temperatura del mare durante i periodi di studio
(http://www.mareografico.it).
In this area the densities and the sizes of the studied organisms are perceptibly higher
than the same species observed in other Mediterranean sites. E. racemosum, for
example, shows densities six-fold higher than Medas Islands (Gili, 1982) while the
common sponge C. reniformis may cover more than a squared metre surface.
Conclusions – The filter-feeders assemblage of the Conero Promontory is composed
by a large number of species, mainly sponges and cnidarians, with an evident seasonal
cycle. Moreover contrarily to the western Mediterranean Sea (Coma et al., 2000;
Bavestrello et al., 2006), the most conspicuous seasonal species typically occur in
summer.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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