MEDLEM database, a data collection on large Elasmobranchs in the Mediterranean and Black seas
The Mediterranean Large Elasmobranchs Monitoring (MEDLEM) database contains more than 3,000 records (with more than 4,000 individuals) of large elasmobranch species from 21 different countries around the Mediterranean and Black seas, observed from 1666 to 2017. The principal species included in the archive are the devil ray (1,868 individuals), the basking shark (935 individuals), the blue shark (622 individuals), and the great white shark (342 individuals). In the last decades, other species such as the thresher shark (187 individuals), the shortfin mako (180 individuals), and the spiny butterfly ray (138) were reported with increasing frequency. This was possibly due to increased public a…
Filling gaps: closing the life cycle of the endangered Mediterranean limpet Patella ferruginea Gmelin, 1791 (Gastropoda, Patellidae)
Several reproductive issues and the larval development of the ferruginous limpet, Patella ferruginea Gmelin, 1791, an endangered species endemic from the western Mediterranean Sea, were studied to fill gaps in the knowledge of its life cycle. Average diameter of mature oocytes was 141.83 μm and mean oocyte density in the ovary was 283,800 oocytes/gram. No significant correlations were found between both oocyte diameter or density and female shell length. Female fecundity (number of oocytes per gonad) was significantly correlated with shell length and varied between 189,200 oocytes in a 40.0 mm female and 5,019,200 oocytes in an 86.4 mm female. However, there was considerable variability, in…
Species diversity of the deep-water gulper sharks (Squaliformes: Centrophoridae:Centrophorus) in North Atlantic waters - current status and taxonomic issues
The gulper sharks (genus Centrophorus) are a group of deep-water benthopelagic sharks with a worldwide dis- tribution. The alpha taxonomy of the group has historically been problematic and the number of species included in the genus has varied considerably over the years and is still under debate. Gulper sharks are routinely caught in mid- and deep-water fisheries worldwide and some have shown a considerable decline in abundance in the last few decades. Clear and consistent species discrimination of Centrophorus is essential for an efficient and sustain- able management of these fisheries resources. Our study used molecular cytochrome oxidase subunit I (COI) and 16S ribosomal RNA gene seque…
Angular roughshark Oxynotus centrina (Squaliformes: Oxynotidae) in captivity feeding exclusively on elasmobranch eggs: an overlooked feeding niche or a matter of individual taste?
A specimen of angular roughshark Oxynotus centrina has been kept successfully in captivity for the first time. Over a period of 24 months, the specimen preyed exclusively on the contents of elasmobranch egg cases, suggesting a specialized trophic niche.
First record of the unicorn leatherjacket Aluterus monoceros (Pisces: Monacanthidae) from the Mediterranean Sea
In March 2000 a 384 mm SL adult male specimen of the unicorn leatherjacket Aluterus monoceros was captured off the Chafarinas Islands (south-western Mediterranean). This report increases the list of fish species recently found for the first time in the Mediterranean Sea.