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

BIONOMIC STUDY OF THE MACROFAUNA OF THE MEDIOLITORAL SOFT SUBSTRATUM IN STRYMONIKOS AND THERMAIKOS GULFS

THE QUALITATIVE AND QUANTITATIVE COMPOSITION OF THE MEDIOLITTORAL BENTHIC COMMUNITIES ON THE SOFT SUBSTRATE IN STRYMONIKOS GULF AND IN THE GULF OF THESSALONIKI ARE ANALYSED. THE COMMUNITIES STUDIED ARE THE FOLLOWING: A) THE COMMUNITY OF THE MEDIOLITTORAL GRAVELS, B) THE COMMUNITY OF THE MEDIOLITTORAL SEDIMENTS IN BRAKISH WATERS AND C) THE COMMUNITY OF THE MEDIOLITTORAL SANDS. THE CORRESPONDING COMMUNITIES IN THE TWO GULFS ARE COMPARED AND THE "SUBCOMMUNITY OF THE POLLUTED MEDIOLITTORAL SANDS WITH TURBELLARIA AND OLIGOCHAETA" IS DESCRIBED. THE LOCAL DISTRIBUTION OF THE POPULATIONS IN THE MEDIOLITTORAL SANDS IS ALSO GIVEN AS WELL AS THE DYNAMICS OF THIS COMMUNITY. THE VARIOUS INFORMATION OBTAINED IS COMPARED TO THAT EXISTING ON THE CORRESPONDING COMMUNITIES INSIDE AND OUTSIDE THE MEDITERRANEAN SEA.ΑΝΑΛΥΕΤΑΙ Η ΠΟΙΟΤΙΚΗ ΚΑΙ ΠΟΣΟΤΙΚΗ ΣΥΝΘΕΣΗ ΤΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΒΕΝΘΙΚΩΝ ΚΟΙΝΟΤΗΤΩΝ ΤΟΥ ΚΙΝΗΤΟΥ ΥΠΟΣΤΡΩΜΑΤΟΣ ΣΤΟ ΚΟΛΠΟ ΤΗΣ ΘΕΣΣΑΛΟΝΙΚΗΣ ΚΑΙ ΤΟΝ ΣΤΡΥΜΟΝΙΚΟ ΚΟΛΠΟ. ΠΡΟΚΕΙΤΑΙ ΓΙΑ ΤΙΣ ΚΟΙΝΟΤΗΤΕΣ: Α) ΤΩΝ ΑΔΡΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΙΖΗΜΑΤΩΝ. Β) ΤΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΙΖΗΜΑΤΩΝ ΣΕ ΥΦΑΛΜΥΡΑ ΝΕΡΑ ΚΑΙ Γ) ΤΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΑΜΜΩΝ. ΟΙ ΑΝΤΙΣΤΟΙΧΕΣ ΚΟΙΝΟΤΗΤΕΣ ΤΩΝ ΔΥΟ ΚΟΛΠΩΝ ΣΥΓΚΡΙΝΟΝΤΑΙ ΚΑΙ ΠΕΡΙΓΡΑΦΕΤΑΙ Η "ΥΠΟΚΟΙΝΟΤΗΤΑ ΤΩΝ ΡΥΠΑΡΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΑΜΜΩΝ ΜΕ TURBELLARIA ΚΑΙ OLIGOCHAETA". ΔΙΝΕΤΑΙΕΠΙΣΗΣ Η ΤΟΠΙΚΗ ΔΙΑΝΟΜΗ ΤΩΝ ΠΛΗΘΥΣΜΩΝ ΤΩΝ ΜΕΣΟΠΑΡΑΛΙΑΚΩΝ ΑΜΜΩΝ, ΚΑΘΩΣ ΕΠΙΣΗΣ ΚΑΙ Η ΔΥΝΑΜΙΚΗ ΤΗΣ ΚΟΙΝΟΤΗΤΑΣ ΑΥΤΗΣ. ΟΙ ΔΙΑΦΟΡΕΣ ΠΛΗΡΟΦΟΡΙΕΣ ΣΥΓΚΡΙΝΟΝΤΑΙ ΜΕ ΕΚΕΙΝΕΣ ΠΟΥ ΥΠΑΡΧΟΥΝ ΓΙΑ ΑΝΤΙΣΤΟΙΧΕΣ ΚΟΙΝΟΤΗΤΕΣ ΕΝΤΟΣ ΚΑΙ ΕΚΤΟΣ ΜΕΣΟΓΕΙΟΥ

Revision of the freshwater genus Atyaephyra (Crustacea, Decapoda, Atyidae) based on morphological and molecular data

Atyaephyra de Brito Capello, 1867 was described from the Mediterranean region almost 200 years ago. Since then, the genus has been recorded from various freshwater habitats in Europe, North Africa and the Middle East. Despite its long history, the taxonomic status of Atyaephyra species remains confusing and uncertain. Consequently numerous specimens from the known range of Atyaephyra were analysed using morphological characters and mitochondrial COI sequences in an attempt to clarify the taxonomy of this genus. The present study recognises seven Atyaephyra species, more than twice as many as previously recorded (three), four of which are considered as new. The new species are described, additional information to the original descriptions are provided for the remaining three taxa, while neotypes of A. desmarestii Millet, 1831 and A. stankoi Karaman, 1972 are designated to stabilize their taxonomy. Non-overlapping distinguishing morphological characters are used to discriminate the examined material into five species, e.g., A. desmarestii, A. stankoi, A. orientalis Bouvier, 1913, A. thyamisensis sp. n., A. strymonensis sp. n. In addition, the genetic analysis supports the existence of multiple phylogenetic clades in the broader Mediterranean area and distinguishes two new cryptic species, namely A. tuerkayi sp. n. and A. acheronensis sp. n. The geographic distribution of these species is confirmed and their phylogenetic relationships are described