Whale shark aggregations in tropical coastal systems are linked to environmental variability and prey dynamics, yet the drivers of surface sightings remain poorly understood. In Nosy Be, Madagascar, a seasonal aggregation of immature whale sharks occurs within a productive coastal ecosystem. This study investigated the relationship between daily environmental conditions and whale shark surface sighting probability while accoun...

Chondrichthyans are among the most threatened vertebrate groups worldwide, yet their ecology and long-term trajectories remain poorly understood in data-limited regions such as the Mediterranean Sea. This study used Local Ecological Knowledge (LEK) provided by fishers to investigate perception-based temporal changes in the reported composition of chondrichthyan taxa across Italian waters. A total of 57 semi-structured intervie...

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 evidenc...

The European eel (Anguilla anguilla), a catadromous species currently listed as Critically Endangered by the IUCN, is undergoing a severe continental decline. Among the multiple contributing factors, chemical contamination of aquatic environments—particularly by heavy metals—plays a major role. This study analyzed the concentrations of 16 trace elements in the muscle tissue of A. anguilla specimens collected from three ecologi...

This collective article presents new information about 15 introduced taxa belonging to five phyla: one Rhodophyta, one Chlorophyta, one Mollusca, one Annelida, two Arthropoda, and nine Chordata (one Ascidiacea and eight Osteichthyes). The records refer to eight Mediterranean countries and extend from the Alboran Sea to the Levantine Sea as follows: Spain: first record of the African hind Cephalopholis taeniops for the Alboran...

Due to their late maturation, extreme longevity, low fecundity and slow growth rates, deep-sea Chondrichthyes are extremely vulnerable to human impacts. Moreover, assessing the impact of deep-sea fisheries is difficult, as many species (including sharks) are part of the bycatch and are often discarded at sea, and/or landed under generic commercial-species codes. The lack of this information on fishery data sets and the limited...

Stable isotopes (δ13C and δ15N) were analysed in vertebrae of Scyliorhinus canicula (n=40; 13 males, 27 females) from the central Tyrrhenian Sea to explore a potential trophic shift in relation to sex and maturity condition. Isotopic values were obtained from the centre and the periphery of the vertebra of each individual to test for the effect of maturity condition. The values of δ13C and δ15N showed significant differences b...

The Mediterranean Sea has a long-lasting history of fishery exploitation that, together with other anthropogenic impacts, has led to declines in several marine organisms. In particular, elasmobranch populations have been severely impacted, with drastic decreases in abundance and species diversity. Based on their experience, fishers can provide information on marine species occurrence, abundance and behavioural traits on a long...

In this contribution the checklist of chondrichthyans of Calabria (Central Mediterranean, southern Italy) is reported. Data presented is derived from twenty years of opportunistic and active surveys from 2000 to 2020. A total of 55 species of chondrichthyans is present in Calabrian seas: 33 sharks, 20 rays, and 2 chimaeras. These species represent approximately 62% of the total reported for the Mediterranean. Approximately 71%...

Grass snakes are widely distributed across the Western Palearctic. Recent phylogeographic studies provided evidence that three distinct parapatric species exist. Two of these occur in Italy, Natrix helvetica and N. natrix , and a contact zone between both taxa has been suggested for north‐eastern Italy. Moreover, previous investigations revealed for the Italian Peninsula a complex phylogeographic structure. Using mtDNA sequenc...

Aim Determine the evolutionary origin of the heretofore poorly characterized contemporary Great White Shark (GWS; Carcharodon carcharias ) of the Mediterranean Sea, using phylogenetic and dispersal vicariance analyses to trace back its global palaeo‐migration pattern. Location Mediterranean Sea. Taxon Carcharodon carcharias . Methods We have built the largest mitochondrial DNA control region (CR) sequence dataset for the Medit...

The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains over 3000 records (more than 4000 individuals) of large elasmobranch species from 20 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The main species included in the archive are the devil fish (1 813 individuals), the basking shark (939 individuals), the blue shark (585 individuals) and the great white shark (33...