Search Results (33)

Directional asymmetry (DA) is a widespread yet often overlooked feature of animal morphology. Here, we report a consistent right-biassed asymmetry in the crystalline lenses of the thornback ray Raja clavata. Across 71 individuals sampled from the Strait of Sicily, 24% exhibited lens asymmetry, and in all cases, the right lens was larger. This pattern, supported by binomial and distributional tests, represents the first evidence of ocular DA in this species. Body size and age emerged as the primary correlates of asymmetry: the odds of exhibiting DA increased significantly with body weight, whereas the effects of sex and sampling site were not significant. The prevalence of asymmetry thus appears to rise with age and ontogenetic growth. Two non-exclusive mechanisms may account for this pattern. First, the association with positive allometry (b = 3.33) suggests that right-lens enlargement could reflect a functional or developmental lateralisation, potentially conferring a visual or ecological advantage to larger individuals. Alternatively, the same right-lens bias could arise through an age-related pathological process, such as oxidative or osmotic lens swelling preceding cataract formation, consistent with asymmetric physiological wear. These findings reveal a novel case of morphological lateralisation in an elasmobranch and highlight the need for comparative, histological, and functional approaches to disentangle adaptive asymmetry from lateralised senescence in the visual system of R. clavata. Full article

The benefits of physical activity on physical and mental health are well established. Exercise can be particularly advantageous in neurodegenerative disorders such as Parkinson’s disease (PD), where progressive loss of muscle mass and impaired motor performance are common. We report the case of a 58-year-old man with PD who underwent a structured, adapted physical activity program in preparation for a relay swim across the Strait of Messina (Sicily, Italy). The aim was to evaluate changes in body composition (fat mass, fat-free mass) and performance following four months of adapted swimming training, alongside adapted physical activity in the gym and Nordic walking. The patient swam 1300 m in 42 min and 38 s in the relay, which was a marked improvement from the baseline and subsequent assessments. In conclusion, while a longer follow-up period and a larger patient sample would be necessary, the findings from this case study suggest that the adapted exercise program improved both physical fitness and body composition. This generally supports the key role of physical activity in managing Parkinson’s disease and, in particular, the positive effects of adaptive sports training. Full article

The identification and location of Sicilian red-figure pottery workshops remain an unresolved issue in archaeological research. Recent studies propose various hypotheses based on the typological and stylistic analyses of the vases and on the distribution of the finds. This paper examines a corpus of red-figure vases from Gela (Sicily), dating from the late 5th to mid-4th centuries BC, attributed to prominent painters from Sicily and Magna Graecia. For the first time, a corpus of fourteen red-figures vases is subjected to X-ray fluorescence elemental analysis (XRF) to compare the results with established compositional data for fine ware Sicilian productions, including those from sites identified in the archaeological literature as potential red-figure workshop centers or areas with relevant attestations. The aim is to geochemically fingerprint the Gela corpus to assess its manufacturing origin and test the prevailing stylistic attribution hypotheses. The compositional similarity in the geochemical fingerprint of the studied corpus points definitively to a single, highly cohesive production area—namely the so-called “Strait of Messina” area, which is distinct from Siracusa which has been traditionally considered the main producer. This finding challenges the existing model of red-figure production in the region and strongly suggests the presence of a major, previously unidentified workshop center serving Gela. Full article

The occurrence of the bigfin reef squid Sepioteuthis lessoniana, a Lessepsian migrant, is documented for the first time from the coastal waters off Malta, based on the collection of a single specimen reported through citizen science. The presence of this species in the broader Strait of Sicily region is further confirmed by a morphometric assessment and genetic analysis of another individual captured off the Pelagian island of Lampedusa. Molecular identification using mitochondrial COI and 16S rRNA markers corroborates the taxonomic identification exercise as it aligns both specimens with Indo-Pacific clades of S. lessoniana. These records represent the first genetically verified occurrences of the species in both Maltese and Italian waters. The findings extend the known Mediterranean distribution of S. lessoniana, emphasizing the Strait of Sicily as an important monitoring region for Lessepsian migrants and highlighting the combined role of integrative taxonomy and citizen science in tracking non-indigenous species introductions. Full article

The Strait of Sicily represents a biogeographically rich and complex region. The diverse geological origin and past continental connection of its islands have shaped a highly heterogeneous fauna, mainly composed of both African and European taxa. The Italian sea-slater, Ligia italica (Fabricius, 1798), is a small isopod inhabiting rocky shores of the Mediterranean Sea, Black Sea, and Atlantic Ocean. Despite its wide distribution, the phylogeography of this species is poorly understood, with limited available data suggesting a remarkable level of cryptic diversity. In this study, we investigated the mitochondrial genetic diversity (COX1) of L. italica across nine Italian and Maltese islands across the Strait of Sicily, aiming to clarify the biogeographic patterns underlying the distribution of these insular populations. Our results reveal an unexpectedly high genetic diversity within our study area, with eight different haplogroups, each characterized by low internal genetic variation and mutual distances ranging from 5.5% to 17.9%. These values are comparable to those associated with species-level rank within the genus Ligia. Overall, the phylogenetic relationships between the lineages appear well supported; however, the same relationships are not clearly correlated with geographic proximity or connectivity among the sampled localities. The distribution patterns of some of the detected haplogroups suggest possible passive dispersal mechanisms (e.g., rafting), while others indicate more intricate biogeographic scenarios. The overall diversity of L. italica within the Strait of Sicily, as well as the unclear origin of some insular populations, cannot be fully explained with the current data. In particular, the high genetic structure observed within the Maltese Archipelago, may partially reflect human-mediated dispersal (e.g., maritime transport), possibly involving source populations that remain unsampled or genetically uncharacterized. Our results highlight that the Strait of Sicily can be considered a diversity hot spot for L. italica and support the designation of this taxon as a putative species complex, with a cryptic diversity worthy of an exhaustive taxonomic revision. Full article

The Mediterranean subpopulation of great white sharks (Carcharodon carcharias) is elusive and likely in decline, though long-term trends remain uncertain due to opportunistic record-keeping, misidentifications, and changing observation effort. We investigated whether spatial changes in shark occurrences during the 21st century correspond with shifts in Atlantic bluefin tuna (Thunnus thynnus) distribution and habitat conditions. We compiled geographically validated sighting and capture records from 1900 onward, mapped 20th- and 21st-century hotspots, and overlaid these with bluefin tuna potential habitat and long-term sea surface temperature (SST) data. Results reveal a clear redistribution of great white shark hotspots: historic coastal focal areas (e.g., Balearic Islands, Maltese Islands, eastern Adriatic, Sea of Marmara) have diminished or disappeared, while offshore zones (southern Strait of Sicily–Gulf of Gabes) and the Aegean coast of Turkey have emerged as contemporary hotspots. These patterns appear to align closely with shifts in tuna feeding grounds and cooler SST (<18 °C). We highlight limitations in using opportunistic and citizen-reported data due to detection biases and misidentifications, underscoring the need for models that correct detectability. Our findings are consistent with the hypothesis of a link between predator distribution, prey dynamics, and changing ocean conditions, and point toward targeted strategies for future conservation and monitoring of this apex predator in a warming Mediterranean. Full article

A FEM model of Shallow Wave Equations (SWE-FEM) is studied, taking into account the variable bathymetry of semi-enclosed sea basins. The model, with a spatially varying Coriolis term, is implemented for the description of combined refraction–diffraction effects, from which the eigenperiods and eigenmodes of extended geographical sea areas are calculated by means of a low-order FEM scheme. The model is applied to the western Mediterranean basin, illustrating its versatility to easily include the effects of geographical characteristics like islands and other coastal features. The calculated resonant frequencies and modes depend on the domain size and characteristics as well as the location of the open sea boundary, and it is shown to provide results compatible with tide measurements at several stations in the coastal region of France. The calculation of the natural oscillation modes in the western Mediterranean basin, bounded by open boundaries at the Strait of Gibraltar and the Strait of Sicily, reveals a natural period of around 6 h corresponding to the quarter-diurnal tidal components, which are stationary and of roughly constant amplitude on the northern coast of the basin and on the west coast of Corsica (France). On the east coast of Corsica, on the other hand, these components are of very low amplitude and in phase opposition. The semi-diurnal tidal components observed on the same tide gauges north of the basin and west of Corsica are also quasi-stationary although they are not resonant. Resonant oscillations are also observed at lower periods, especially at a period of around 3 h at the Sète station. This period corresponds to a higher-order natural mode of the western Mediterranean basin, but this resonance seems to be essentially linked to the presence of the Gulf of Lion, whose shallowness and the width of the shelf at this point induce a resonance. Other oscillations are also observed at lower periods (T = 1.5 h at station Fos-sur-Mer, T = 45 min in the Toulon harbour station), due to more local forcing. Full article

Age determination through reading annual rings in whole otoliths is a complicated, time-consuming task that can lead to errors in population age structure, negatively affecting marine fish management plans. Recently, Fourier transform near-infrared spectroscopy (FT-NIRS) has been successfully used to evaluate annual age, at least in several long-life fish species. European anchovy (Engraulis encrasicolus) is an important pelagic species for its ecological role and socioeconomic value. In the Mediterranean Sea, anchovy stocks are regularly monitored for assessment purposes, and fish age is calculated by traditional otolith reading. In the present study, anchovies, caught over a decade (2012 to 2023) during on-board surveys in four different areas (i.e., North Tyrrhenian, South Tyrrhenian, North of Sicily, and Strait of Sicily), provided an otolith collection used to acquire absorption spectra by FT-NIRS. These spectra were processed to optimize calibration models, and the best linear models obtained revealed a good predictability for anchovy annual age (coefficient of determination of 0.90, mean squared error 0.3 years, bias < 0.001 years). The calibration model developed for all regions combined proved more robust than the models for each area, demonstrating its efficacy for the entire study area. FT-NIRS analyses proved suitable for predicting age, when applied to E. encrasicolus individuals within the age range of 0 to 3, also when compared to traditional aging methods. Moreover, this methodology improved the standardization of age estimates. Finally, this preliminary study encourages the further application of FT-NIRS also to short-life pelagic species involved in stock assessment plans. Full article

The invasion history of the gastropod mollusk Bursatella leachii in the Mediterranean Sea demonstrates a dynamic progression through distinct phases, comprising arrival, establishment, and expansion phases. Initial records in the 1930s trace its entry through the Suez Canal, likely followed by larval transport to the Aegean Sea facilitated by natural currents. The subsequent spread to Maltese and Italian waters suggests secondary dispersion favored by maritime traffic or aquaculture activities. The establishment phase shows a significant increase in occurrences and spatial dispersion, with aggregated nuclei in the central Mediterranean. The expansion phase was characterized by rapid dispersal and intensified densities, particularly in the Aegean, Adriatic, and Spanish coasts. These findings underscore the species’ capability to invade from multiple fronts, driven by both natural and human-mediated processes. A new location in the Strait of Sicily, i.e., the island of Lampedusa, is reported in the present paper for the species. Given the low number of observations, its establishment with a viable population on the island is not confirmed, although its detection validates the Straits of Sicily as a key area of intense settlement of the species. Full article

In the shift toward sustainable energy production, offshore wind power has experienced notable expansion. Several projects to install floating offshore wind farms in European waters, ranging from a few to hundreds of turbines, are currently in the planning stage. The underwater operational sound generated by these floating turbines has the potential to affect marine ecosystems, although the extent of this impact remains underexplored. This study models the sound radiated by three planned floating wind farms in the Strait of Sicily (Italy), an area of significant interest for such developments. These wind farms vary in size (from 250 MW to 2800 MW) and environmental characteristics, including bathymetry and seabed substrates. Propagation losses were modeled in one-third-octave bands using JASCO Applied Sciences’ Marine Operations Noise Model, which is based on the parabolic equation method, combined with the BELLHOP beam-tracing model. Two sound speed profiles, corresponding to winter and summer, were applied to simulate seasonal variations in sound propagation. Additionally, sound from an offshore supply ship was incorporated with one of these wind farms to simulate maintenance operations. Results indicate that sound from operating wind farms could reach a broadband sound pressure level (L_p) of 100 dB re 1 µPa as far as 67 km from the wind farm. Nevertheless, this sound level is generally lower than the ambient sound in areas with intense shipping traffic. The findings are discussed in relation to local background sound levels and current guidelines and regulations. The implications for environmental management include the need for comprehensive monitoring and mitigation strategies to protect marine ecosystems from potential acoustic disturbances. Full article

The Mediterranean Sea is a hotspot for the introduction of non-indigenous species. Among them, invasive alien species can seriously affect the areas they colonize, not only by altering the marine food webs and community structure, but also by harming certain economic activities, such as fishing, tourism, aquaculture and marine infrastructure. Rugulopteryx okamurae is a brown macroalga considered the fourth most harmful species among the 10 most invasive species reported in the Mediterranean; in fact, it has recently been included in the list of invasive alien species of Union concern due to its serious impact on biodiversity and socioeconomic implications. This species was reported for the first time in the Mediterranean in 2002 in Thau Lagoon (France), introduced by the aquaculture of the Japanese oyster Magallana gigas. Since then, this species has spread in both the Mediterranean and Atlantic Ocean with a strong invasive behavior, particularly along the Strait of Gibraltar. Rugulopteryx okamurae was also recently reported for the first time in Italian waters, in the Gulf of Palermo (Sicily). In this study, we report a record of this species further to the east, in the Ionian Sea, where it has not previously been recorded, and provide possible explanations of the spreading and arrival routes in this area. The rapid expansion of R. okamurae is raising concerns; thus, in order to safeguard native communities, it is crucial to keep monitoring this invasive species so that it is possible to regularly update its distribution and follow up on its spread dynamics in the Mediterranean basin. Full article

The sea star Hymenodiscus coronata is the only Mediterranean representative of the deep-sea order Brisingida. In the North-eastern Atlantic Ocean, this species is known to create dense aggregations, while, in the Mediterranean basin, it is generally reported as scattered individuals. Through the analysis of the video footage obtained from an extensive ROV campaign carried out in the northern Strait of Sicily in 2021, over 2850 specimens were counted. The specimens, observed between 310 m and 714 m depth, showed a large variability in size and number of arms. It was noted that 17% of the specimens displayed the peculiar “sail position”, with all the arms extended vertically in the water column, possibly increasing the filtration rate. Almost the totality of the individuals was noted on soft bottoms, in accordance with the ecological preferences of the species. The density of H. coronata in each site varied between 0.01 and 0.81 individuals m⁻², with the highest densities reported in sites characterized by large muddy areas among rocky outcrops and turbulent hydrodynamic conditions. Although the trawling areas exploited in 2021 did not seem to interfere with the presence of H. coronata in the study area, a precautionary approach should be assumed to protect the largest ever reported Mediterranean aggregation of this poorly known species. Full article

This study provides new insights regarding the ecology and phenology of the likely non-indigenous canopy-forming species Sargassum furcatum on the central-eastern coast of Sicily (Italy, Central Mediterranean). This species was described for St. Thomas (Virgin Islands), and it was reported for the first time in the Mediterranean in 1995 in the Chafarinas islands (Spain, western Mediterranean). After the first report, this species was found in 2021 in several sites located along the eastern coast of Sicily (Italy), along the French Mediterranean coastline, in Corsica, and recently also in the Aeolian Islands (Italy). No phenological studies on this species have been ever carried out in the Mediterranean Sea. To conduct this study, a visual census activity was performed in three sites along the Ionian coast of Sicily throughout 2023, during which the length of the main axis of S. furcatum specimens was measured and the frequency of findings of the species during the year was noted. In this study, it was observed that S. furcatum shows a wide adaptability in terms of range of depth, temperature, light exposure, and type of substrate. Since the distribution of this species is mostly centralized in the western Atlantic Ocean, it is likely that S. furcatum entered the Mediterranean through the Gibraltar Strait. Consequently, the entrance of this species in this Basin could be further proof of the ongoing seawater warming and tropicalization of Mediterranean waters. From this point of view, it is important to keep monitoring the dynamics of S. furcatum in the Mediterranean Sea in order to understand its putative impacts on autochthonous communities. Full article

This study aims to analyze the dynamics of change in settlement models from the Roman, late antique, and Byzantine periods, focusing on how these transformations influenced the formation of Islamic societies in the rural landscapes of western Sicily. The study is centered around the territory of Corleone in the Sicani Mountains (central-western Sicily). This region, strategically located between the significant cities of Palermo on the Tyrrhenian Sea and Agrigento on the Strait of Sicily, has been pivotal in the communication network spanning from the Roman era to the Middle Ages and beyond. The area has been subject to extensive surveys and excavations, revealing diverse dynamics of continuity, resilience, and innovation in settlement patterns from the Roman to the Islamic periods. Beyond presenting the results of archaeological fieldwork, this study employs GIS-based spatial and statistical analyses and utilizes a range of topographic (elevation, slope, aspect, topographic position index (TPI), and distance to water sources) and ecological factors (vegetation series). These analyses aim to assess the evolving relationships and site positioning within the territory over time. Combining archaeological data with topographic and ecological landscape analysis, this integrated approach elucidates the complex transition dynamics from the Roman settlement system to the Islamic age’s landscape formation in western Sicily’s rural areas. The study thereby contributes to a deeper understanding of the intricate interplay between historical developments and environmental factors in shaping rural settlement patterns. Full article

A new species, Baetis (Baetis) dihyaesp. nov., belonging to the Baetis alpinus species group, is described and illustrated based on larval material collected in the Aurès Mountains (northeastern Algeria) in 2020–2021. This new species is closely related to three European species, e.g., Baetis (B.) alpinus (Pictet, 1843); B. (B.) nubecularis Eaton, 1898; and B. (B.) pasquetorum Righetti & Thomas, 2002 by the combination of the following characteristics: (i) more than one short, stout bristle at the tip of segment II of the maxillary palp and (ii) a well-developed paracercus. However, the new species clearly differs from all congeners of the Baetis alpinus species group primarily by the (a) structure of mouthparts—with 14–18 long submarginal setae arranged in a single irregular row on the dorsal surface of the labrum; 2–6 short, stout bristles at the tip of segment II of the maxillary palp; and segment II of the labial palp without a considerably developed apico-internal lobe); (b) setation of abdominal terga, with a few triangular-shaped scales sparsely scattered near the posterior margin only; and (c) a well-developed paracercus, comprised of more than 50 segments. Primary data on the biology and distribution of this new species are provided, and molecular affinities are verified by the analysis of COI (barcode) sequences. Detailed notes on the distribution of mayfly species belonging to the Baetis alpinus species group common in Western Europe and the western part of North Africa are presented. The historical movement of Baetis representatives between Europe, North West Africa, and subsequently Algeria, with the land bridges ‘Strait of Gibraltar’ and ‘Strait of Sicily’ as colonization routes, is discussed in detail and identified in the present study as the Western Algeria colonization path and Eastern Algeria colonization path, respectively. Full article