Elasmobranchs represent important components of marine ecosystems, but they can be vulnerable to overexploitation. This has driven investigations into the population genetic structure of large-bodied pelagic sharks, but relatively little is known of population structure in smaller demersal taxa, which are perhaps more representative of the biodiversity of the group. This study explores spatial population genetic structure of the small-spotted catshark (Scyliorhinus canicula), across European seas. The results show significant genetic differences among most of the Mediterranean sample collections, but no significant structure among Atlantic shelf areas. The data suggest the Mediterranean populations are likely to have persisted in a stable and structured environment during Pleistocene sea-level changes. Conversely, the Northeast Atlantic populations would have experienced major changes in habitat availability during glacial cycles, driving patterns of population reduction and expansion. The data also provide evidence of male-biased dispersal and female philopatry over large spatial scales, implying complex sex-determined differences in the behaviour of elasmobranchs. On the basis of this evidence, we suggest that patterns of connectivity are determined by trends of past habitat stability that provides opportunity for local adaptation in species exhibiting philopatric behaviour, implying that resilience of populations to fisheries and other stressors may differ across the range of species.

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 (337 individuals).In the last decades other species such as the shortfin mako (166 individuals), the spiny butterfly ray (138) and the thresher shark (174 individuals) were reported with an increasing frequency. This was possibly due to an increased public awareness on the conservation status of sharks, and a consequent development of new monitoring programmes. MEDLEM does not have a homogeneous reporting coverage throughout the Mediterranean and Black seas and it should be considered as a database of observed species presence. Scientific monitoring efforts in the south-eastern Mediterranean and Black seas are generally lower than in the northern sectors and the absence in our database of some species does not imply their actual absence in these regions. Some considerations are made on the frequency and spatial distribution of records, size structure of the observed individuals for selected species, general area coverage and species involved as by-catch by fishing gear.

The aim of this study was to determine and compare differences in physical, chemical and sensory post-mortem changes between wild (W) and farmed (F) gilthead sea bream (Sparus aurata). Ungutted fish were stored in ice from harvesting up to 20 days and freshness indicators were analyzed at regular intervals. Proximate composition of the samples differed in lipid (W = 0.86 ± 0.12; F = 4.18 ± 0.16) and moisture content (W = 79.12 ± 0.48; F = 74.50 ± 0.82). Data from sensory evaluation were described using linear regression models. Sensory schemes for cooked and raw fish were found to be suitable in establishing specific attribute deterioration and shelf life duration (W = 14 days; F = 17 days). Changes in pH and dielectric properties were influenced by differences in lipid content, while changes in total volatile base nitrogen and trimethylamine showed high correlation with sensory assessment and storage time, but stayed below the acceptance limit for human consumption (W : 24.47 mg TVB-N/100 g and 4.14 mg TMA-N/100 g; F : 26.18 mg TVB-N/100 g and 3.84 mg TMA-N/100 g), and thus were not reliable indicators of quality changes during storage in ice. Deterioration of flesh lipids, assessed by thiobarbituric acid index, differed between the samples, but presented no serious problem during storage time. In order to determine the importance of individual results, all obtained data were submitted to principal component analysis. Variations in sensory, physical and chemical assessment were described by PC1 (storage time); variations in lipid and moisture content were described by PC2 (capture grounds). A clear separation of the investigated samples, according to the storage time and capture grounds, was observed.

Although there is a high number of publications listing fish species in the Adriatic, only a few have focused on chondrichthyans, while their conservation status has been investigated even less. Thus, this paper aims to provide an updated and annotated checklist of the chondrichthyans occurring in the Adriatic waters with their presence and conservation status. Each species is evaluated against the criteria defined in IUCN (International Union for Conservation of Nature) Red List Categories and Criteria and according to the guidelines for national and regional level assessments. In total, 60 chondrichthyan species from 27 families and 42 genera are listed. The list contains 33 species of sharks, 26 species of rays and one chimera. Assessment of the conservation status reveals that three species are now considered Regionally Extinct (namely Squatina oculata, Pristis pectinata and Rhinobatos rhinobatos). A total of 21 species are assessed as Critically Endangered, 8 are Endangered and 10 are Vulnerable. Of the remaining species, six are Near Threatened and the same number of species are Least Concern and Data Deficient. Considering that the principal driver of chondrichthyan decline and regional extinction is overfishing, it is recommended that the Adriatic countries adopt the same management measures and strengthen their coordination.