The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well

Seasonal cycle of Jassa mormorata Holmes, 1903 (Amphipoda) in the Ligurian Sea (Mediterranean, Italy)

This paper describes the life cycle of the amphipod Jassa marmorata with data recorded over two years (from May 2002 to April 2004) in the Marine Protected Area of Portofino (Ligurian Sea, Italy). The population was sampled monthly at 5 m depth on artificial substrata. For each sample, the number of males, females, ovigerous females, and juveniles was recorded and related to water temperature. Two kinds of males, minor and major, were found, distinguishable by the presence of a thumb on the second gnathopod. The sex-ratio was significantly biased towards females (F:M¼5.6:1). The cycle revealed a female increase in mean body size during the cold season (late winter and early spring). This resulted in a peak in recruitment during the spring; females are fertile all through the year, but egg production is positively correlated with female size. During the summer of 2003, an anomalous increase in sea-water temperature was recorded. In this period the population completely disappeared, but the density during the next winter recovered again to usual values

SPONGES FROM A SUBMARINE CANYON OF THE ARGENTINE SEA.

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Patch-clamp recordings in isolated sponge cells.

Sponges are the most ancient known metazoans. Their cells are specialised but not organised into tissues or organs. Recordings of action potential-like propagating electrical impulses suggested that electrical signalling may occur between sponge cells, but the characterization of ionic channels in these cells is still at the beginning. Actually, sponge cell surfaces are covered by a complex glycocalyx and long-chain fatty acids are present in the lipid core of their membranes. In these experimental conditions, a low percentage of tight seals (3%) was obtained applying the patch-clamp technique to cells isolated from the Mediterranean Demospongia Axinella polypoides. This paper shows in detail how difficulties can be overcome making use of trivalent cations in the extracellular solution and how electrophysiological measurements can be performed on sponge cell membranes. A potassium selective conductance is shown as an example. We suggest that the presented methodology could also be applied to other cell types

Assessment of fungal growth and colonization rate on silicone: preliminary results

none6ZOTTI M; DI PIAZZA S; CERRANO C; A MONTEMARTINI; SGRO C; MARIOTTI MZotti, Mirca; DI PIAZZA, S; Cerrano, Carlo; Montemartini, Aurora; Sgrò, Carmela; Mariotti, Maur

Oxygenated cembranoids of the decaryiol type from the Indonesian soft coral Lobophytum sp.

Three novel cembrane diterpenoids, decaryiols B-D (5-7), characterized by a bicyclic skeleton of the decaryiol-type, have been isolated from the Indonesian soft coral Lobophytum sp., along with three known cembranoids. The stereostructures of these metabolites have been established through extensive NMR spectroscopic analysis, application of the modified Mosher method, and chemical conversion. Cembranoids obtained from Lobophytum sp. (2-7) and six semisynthetic derivatives (9-14) prepared from decaryiol were tested for cell growth inhibitory activity against three different cell lines. O-Methyl decaryiol (10) exhibited a significant and selective activity against glioma cell lines