Comparative Analysis of Mollusc Assemblages from Different Hard Bottom Habitats in the Central Tyrrhenian Sea

Abstract

Composition, trophic structure, and species-substrate relationships of molluscan assemblages inhabiting different hard bottom habitats (Sabellaria alveolata reef, photophilic bottoms, Phyllophora crispa sciaphilic assemblage, and coralligenous bioconstruction) were studied in two different sites of the Tyrrhenian Sea. In particular, molluscs from the Sabellaria alvevolata (Linnaeus, 1767) reef and coralligenous concretion were investigated, testing the hypothesis that bioconstructions increase the diversity and abundance of associated biota compared to the surrounding habitats. A total of 3134 individuals belonging to the classes of Polyplacophora (5 species, 24 individuals), Bivalvia (39 sp., 2734 ind.), and Gastropoda (53 sp., 376 ind.) were identified. These three taxonomic groups showed different distribution patterns in the studied habitats. Multivariate analyses revealed significant inter-habitat differences in the composition of mollusc assemblages, especially between bioconstructions and the other habitats. S. alveolata and coralligenous host the highest rich molluscan fauna when compared to the neighboring hard bottom habitats characterized by photophilic and sciaphilic assemblages. The first ones were dominated by bivalve suspension feeders, mainly represented by sessile and sedentary organisms, which act as bio-constructors, bio-eroders, or simply inhabit the several microhabitats provided by the bioconstructions, while the second ones host a rich molluscan fauna dominated by gastropod grazers and predators. The present study increases the comparative knowledge of molluscan assemblages inhabiting habitats of littoral plans of the Mediterranean Sea, providing pivotal information regarding biodiversity of coastal zones.

Environmental and Benthic Community Patterns of the Shallow Hydrothermal Area of Secca Delle Fumose (Baia, Naples, Italy)

“…It is well-known that benthic species are functionally and structurally related to the main features of the habitat they reside (e.g., Woodin, 1978;Thrush et al, 1991;Desprez, 2000;Riera et al, 2012;Donnarumma et al, 2018;Casoli et al, 2019). In particular, the taxa composition recorded in the control sites was consistent with a marked occurrence of gravel, which offers microhabitats suitable for settlement and refuge.…”

Capitoline Dolphins: Residency Patterns and Abundance Estimate of Tursiops truncatus at the Tiber River Estuary (Mediterranean Sea)

“…However, crossing the city of Rome, it collects waste, organic material, and heavy metals, thus increasing the level of pollution when flowing into the sea [27,28]. The simultaneous presence of both fresh and salt waters, as well as the geomorphological action of sedimentation and erosion, generate different ecological gradients, making the area highly productive and rich in coastal biodiversity [29][30][31][32]. Portions of the seabed of the Roman coast, north and south of the two mouths of the Tiber, include habitats of biological importance (i.e., coralligenous reefs and Posidonia oceanica meadows), which are included in the EU Natura 2000 network Sites of Community Importance (SCI).…”

<p class="ZootaxaTitle"><strong>Distribution of<em> Sabellaria alveolata</em> (Polychaeta Sabellariidae) in the Mediterranean Sea: update and new findings</strong></p>

“…Only publications based on real findings/ records of S. alveolata were selected and critically reviewed discarding mentions/listing based on records by previous authors. Campoy (1982), Porras et al (1996) D Gulf of lyon and ligurian Sea 3 Marseilles (France) Bellan (1964) 4 Quarto (Genoa -Liguria) Issel (1918) 5 Chiavari, Gulf of Tigullio, Lavagna 8 Civitavecchia (Lazio) Giordani-Soika (1956), Somaschini (1988) 9 Ostia Lido (Roma -Lazio) Bonifazi et al (2019), Casoli et al (2019, Lisco et al (2020) 10 Tor Caldara (Latina -Lazio) Taramelli-Rivosecchi (1961), Nicoletti et al (2001), La Porta et al (2006), La Porta & Nicoletti (2009) 11 Lavinio (Anzio -Lazio) Taramelli-Rivosecchi (1961), Gambi et al (1996), Nicoletti et al (2001) ...Continued on the next page Torre Paola (Latina -Lazio) La Porta et al (2006), La Porta & Nicoletti (2009) Circeo (Latina -Lazio) Chimenz Gusso et al (1995), Nicoletti et al (2001) Gulf of Naples (Campania) Lo Bianco (1888, 1893), Giordani-Soika (1956) Salerno, Policastro (Campania) Giordani-Soika (1956) Castellammare del Golfo (Trapani -Sicilia) Field inspections were performed in subsequent times during several years (September 2013 to May and September 2019) at different localities along the southeastern coast of Sicily to localize sites hosting sabellariid bioconstructions. Four sites were identified (details are given in Fig.…”