Salvatore Giacobbe

The new potential invader Linopherus canariensis (Polychaeta: Amphinomidae) in a Mediterranean coastal lake: Colonization dynamics and morphological remarks

The newly introduced polychaete Linopherus canariensis Langerhans, 1881 was found in the Lake of Faro (NE Sicily), during a study comparing the macrobenthos in artificial modules with a neighboring sandy bottom assemblage. Of a total of 4465 specimens, almost 6% showed morphological variation related to branchial turfs and mean body size. The sandy bottom exhibited an average density of 41.86 ind L⁻¹ and a wet biomass of 30.35 mg L⁻¹, whereas the artificial substratum reached levels of 205.29 ind L⁻¹ and 318.44 mg L⁻¹. The highest estimated immigration rate was 3.7 ind L⁻¹d⁻¹ (5.8 mg L⁻¹ d⁻¹). In the artificial microhabitat, 0.4% of the population showed mid-anterior fragmentation, with anterior- (2%), mid- (< 1%) and posterior- (1%) regenerating lineages, which contributed significantly to the dispersion ability of this species. L. canariensis was a selective micro-deposit feeder, even under conditions of reduced sediments. Linopherus was found to be a new potential invader of stressed environments that is probably tied to the import of oysters.

Environmental quality assessment of Grand Harbour (Valletta, Maltese Islands): a case study of a busy harbour in the Central Mediterranean Sea

Contamination levels by plastic debris, trace elements and persistent organic pollutants were assessed and related to macrobenthic diversity within soft bottoms of Grand Harbour (Malta, Central Mediterranean). Sediment toxicity was evaluated by ecotoxicological method, deploying Bacteria (Vibrio fischeri), Echinodermata (Paracentrotus lividus) and Crustacea (Corophium orientale). Univariate analysis (Pearson’s test) was used to test relationships between biodiversity indices, pollutants and grain size. A multivariate approach (PERMANOVA) was applied to investigate for any significant differences among sampling stations concerning plastic abundances and to test the relationship between infaunal abundances and pollutant concentrations (the BIOENV test). Significant differences in the plastic abundances were found between sampling stations. The lowest value for Shannon-Wiener biodiversity index was associated to the highest sediment pollution level. Multivariate analyses suggest that MBT and TBT were factors that most influenced macrozoobenthic abundance and biodiversity. The bivalve Corbula gibba and the introduced polychaete Monticellina dorsobranchialis were the most abundant found species

Epibiontic mollusc communities on Pinna nobilis L. (Bivalvia, Mollusca)

Epibiontic mollusc communities associated with Pinna nobilis L. in the Straits of Messina (Sicily, Italy) are described. Some relationships were found between species richness and diversity in respect to shell size. Progressive variations in community structure were found, demonstrating how epibiontic communities evolve towards a well-characterized biocoenosis. On the contrary, environmental and anthropogenic disturbances hinder this process, favouring an increase in species richness and Shannon-Wiener diversity.

Ecological assessment of a heavily human-stressed area in the Gulf of Milazzo, Central Mediterranean Sea: an integrated study of biological, physical and chemical indicators.

Marine environmental disturbance can be assessed directly from physical and chemical parameters, or indirectly by the study of indicator species. In this study, an integrated approach to monitor the Gulf of Milazzo, labeled as a highly contaminated site, is presented. A total of 83 samples were collected from hard and soft bottoms in 2010. In sum, 2739 specimens belonging to 246 taxa, two first records for the Tyrrhenian Sea (Micronephthys stammeri and Nicomache lumbricalis) and three nonindigenous species (Brachidontes pharaonis, Crassostrea gigas and Notomastus aberans) were recorded. Biodiversity and biotic indices and their relationship with sediment parameters and the level of pollutants were assessed to describe faunal assemblage and evaluate environmental quality. Pearson tests evidenced significant negative correlation between polychlorinated biphenyls (PCBs) and specific richness (p<0.10). A comparison of the standard and recorded biotic values showed that M-AMBI seems to be the index more representative of ecological quality status (EcoQ) in the Gulf of Milazzo. No evident signs were highlighted on the complex.

Corbula gibba (Mollusca: Bivalvia) death assemblages in Augusta harbour, Mediterranean Sea

Death assemblages found in the Augusta Roadstead harbour (Mediterranean Sea) reflected some modifications in benthic environment that occurred since the 1960s, when the construction of dams closed the commercial harbour. In particular, evidence of a drop in the hydrodynamic levels were found, together with a mud sedimentation increasing. Furthermore, a turbidity phase characterized by a dominant Corbula gibba was identified as due to extensive dredging. Such temporary communities, distributed in accordance to the degree of instability and pollution, preceded the present day, very poor and destructured benthic assemblages.

“Opisthobranch” (mollusks) inventory of the Faro Lake: a Sicilian biodiversity hot spot

Abstract A census of the “opisthobranch” fauna in the Faro Lake and connected canals (NE Sicily) has been realized by photo documentation and specimen samplings, carried out monthly from February 2010 to the present. A total of 47 species have been reported, nine of which are cited in the historic and recent literature (from 1969 to 2016) vs. 38 first records; six were non-indigenous species. A major number of species, 16, was found exclusively in the lake with respect to the four species localized in the canals, whilst 10 were shared species. Based on the frequency of records, 24 “occasional”, 20 “settled” and three “invasive” species have been distinguished; these latter included two non-indigenous species, Aplysia dactylomela and Bursatella leachii, plus the Mediterranean Dendrodoris limbata, whose recent introduction in the Faro Lake from other Mediterranean lagoons is here postulated.

Description of a new species of Abyssoninoe (Polychaeta: Lumbrineridae) from north-east Sicily (central Mediterranean Sea)

michela d’alessandro, andrea cosentino, salvatore giacobbe, franco andaloro and teresa romeo ISPRA, Institute for Environmental Protection and Research, STS Palermo, Laboratory of Milazzo, Via dei Mille, 46 98057 Milazzo (ME), Italy, Department of Biological and Environmental Science, University of Messina, Viale Stagno d’Alcontres, 31–98166 S. Agata, Messina, Italy, ISPRA Institute for Environmental Protection and Research, STS Palermo, c/o Marbela Residence, via Salvatore Puglisi 9, 90143 Palermo, Italy

Caulerpa taxifolia var. distichophylla: a further stepping stone in the western Mediterranean

BackgroundIn the Mediterranean sea, about 150 species of invasive macroalgae are recorded until now these alien species have produced serious effect due to their capability to modify the physical and chemical property of the invaded habitats and to compete with native assemblages so as threatening the biodiversity and the ecosystem functioning.ResultsBased on morphological characters, the invasive green alga Caulerpa taxifolia var. distichophylla, has been recognised for the first time in the Strait of Messina area, off the northeastern coast of Sicily (Tyrrhenian Sea, western Mediterranean). This record confirms the rapid spread of this taxon from the Levantine area towards the western basins, and suggests a human-mediated dispersion. The new invader occurs in different habitats than C. taxifolia (Vahl) C. Agardh, and the respective habitats do not overlap in the Strait of Messina. A previously undescribed association of this species with tropical–subtropical phanerogams and green algae, is a further example of the global change-mediated reorganisation of Mediterranean benthic assemblages.ConclusionsThis record expands the known distribution range of this invasive green algae in Mediterranean Sea.

The genus Antedon (Crinoidea, Echinodermata) in the Strait of Messina and the nearby Tyrrhenian Sea (Central Mediterranean)

The high morphological variability of antedonids under different ecological conditions explains some uncertainties of their Mediterranean distribution. A comparison of Antedon specimens from the Strait of Messina and the nearby Tyrrhenian Sea documented the presence of two phenotypes, distinguished by cirral shape, articulation, and surface microsculpture, referred to the Mediterranean species Antedon mediterranea and A. bifida moroccana. The number of cirrals, the main diagnostic character in the genus Antedon, proved to be statistically discriminant at the species level as well as at lower levels, according to the populations place of origin, inside a very restricted area. These results agree with the hypothesis that the Strait of Messina is an area with high Atlantic affinity, where A. bifida moroccana tends to replace the Mediterranean endemic A. mediterranea, although the two species can be locally sympatric.

Mapping toxic mineral contamination: the southern oyster drill, S. haemastoma (L., 1767), as evaluable sentinel species

The nickel, chromium, arsenic, cadmium, and lead content have been evaluated, by ICP-MS, in digestive gland of the amphiatlantic gastropod Stramonita haemastoma, sampled along the highly anthropized Gulf of Milazzo (Central Mediterranean). Concentrations notably higher than those reported in literature for other Mediterranean Muricidae have been recorded. The results also indicated a different impact in different sites, according to distribution and typology of human activities, whilst recorded seasonal variations might relate with rapid metabolic response. Such preliminary results suggest S. haemastoma may be considered a promising sentinel species for inorganic contamination in marine environment, especially in terms of short-medium-term exposure.