Athanasios Koukouras

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. This abstract has been translated to other languages (File S1).

Population Dynamics, Reproduction and Growth of Upogebia Pusilla (Decapoda, Thalassinidea) in the Evros Delta (North Aegean Sea)

[Monthly samples of Upogebia pusilla were collected from February 1983 to February 1984 in an area of the Evros Delta located close to the sea, where salinity and temperature of the water ranged from 4 to 25% and 4.3° to 24.5°C, respectively. Population density and wet weight biomass varied greatly, being higher in summer. Young shrimps appeared in August and had a maximum life span of approximately three years. Ovigerous females were found from April to August. The frequency of females among the collected individuals was 0.393. The smallest ovigerous female had a total length (TL) of 39 mm, while the maximum TL for females was 82 mm and for males 106 mm. Growth in age classes I and II was greater in the period from July to August. Mean growth of carapace length (CL) was described by the Von Bertalanffy function. A positive correlation existed between total length and CL or wet weight (W)., Monthly samples of Upogebia pusilla were collected from February 1983 to February 1984 in an area of the Evros Delta located close to the sea, where salinity and temperature of the water ranged from 4 to 25% and 4.3° to 24.5°C, respectively. Population density and wet weight biomass varied greatly, being higher in summer. Young shrimps appeared in August and had a maximum life span of approximately three years. Ovigerous females were found from April to August. The frequency of females among the collected individuals was 0.393. The smallest ovigerous female had a total length (TL) of 39 mm, while the maximum TL for females was 82 mm and for males 106 mm. Growth in age classes I and II was greater in the period from July to August. Mean growth of carapace length (CL) was described by the Von Bertalanffy function. A positive correlation existed between total length and CL or wet weight (W).]

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

Abstract 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 Atyaephyra desmarestii Millet, 1831 and Atyaephyra 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., Atyaephyra desmarestii, Atyaephyra stankoi, Atyaephyra orientalis Bouvier, 1913, Atyaephyra thyamisensis sp. n., Atyaephyra 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 Atyaephyra tuerkayi sp. n. and Atyaephyra acheronensis sp. n. The geographic distribution of these species is confirmed and their phylogenetic relationships are described.

PROSOBRANCH MOLLUSC FAUNA OF THE AEGEAN SEA: NEW INFORMATION, CHECKLIST, DISTRIBUTION

ABSTRACT The gastropod mollusc fauna of the North Aegean Sea was investigated during the last 20 years. Examination of the material collected from that area revealed the presence of 279 prosobranch mollusc species. One hundred of them are new records for the mollusc fauna of the North Aegean Sea, 9 for the Aegean Sea and 10 for the Eastern Mediterranean. An updated checklist of the Aegean prosobranch molluscs including 420 species is presented for the first time. All the six prosobranch orders living in the Mediterranean were found to be represented in the Aegean. A zoogeographical analysis of the Aegean prosobranch mollusc fauna showed that the bulk of the species are Atlanto—Mediterranean, followed by Mediterranean endemics and Boreal. Only 5 of the Mediterranean species of Indo-Pacific origin have been found in the Aegean, mostly in the southern part. A comparison of the Aegean prosobranch fauna with those of the other Mediterranean areas, showed that the number of species in the Aegean is higher than ...

ACTINIARIA, CORALLIMORPHARJA, AND SCLERACTINIA (HEXACORALLIA, ANTHOZOA) OF THE AEGEAN SEA, WITH A CHECKLIST OF THE EASTERN MEDITERRANEAN AND BLACK SEA SPECIES

ABSTRACT Twenty-one hcxacoral species belonging Lo the orders Actiniaria (3), Corallirnorpharia (1), and Scleractinia (17) were collected in the North Aegean Sea. Three of these (Amphianthus dohrnii, Cladopsammia rolandi, and Monomyces pygmaea ) are new records for the Eastern Mediterranean and two ( Lophelia pertusa and Madrepora oculata) are new records for the Aegean Sea. It was estimated that 56 species belonging to these three orders have been found in the Eastern Mediterranean and Black Sea and are presented here for the first time in a checklist. Zoogeographical consideration of the Eastern Mediterranean hexacoral fauna shows that the bulk of the species can be characterized as Atlanta-Mediterranean, fo llowed by the Mediterranean endemic and cosmopolitan species. In the Aegean, Atlanta-Mediterranean species dominate both in the order Acti niaria (78.5%) and in Scleractinia (70%). However, cosmopolitan species are more numerous among Scleractinia (25%) than among Actiniaria (3.6%); in the latter, e...

The genera Atergatis , Microcassiope , Monodaeus , Paractea , Paragalene , and Xantho (Decapoda, Xanthidae) in the Mediterranean Sea

[A review of the relevant literature and a comparative study of adequate samples from the Mediterranean Sea and the Atlantic Ocean, revealed new key morphological features that facilitate a distinction of the Mediterranean species of Xanthidae. Based on this study, the Mediterranean Xantho granulicarpus Forest, 1953 is clearly distinguished from the Atlantic Xantho hydrophilus (Herbst, 1790) and Monodaeus guinotae Forest, 1976 is identical with Monodaeus couchii (Couch, 1851). For the species studied, additional information is given about their geographical distribution, as well as an identification key based on selected, constant features. Literaturstudien und vergleichende Untersuchungen geeigneter Proben aus dem Mittelmeer und dem Atlantischen Ozean haben neuen morphologische Schlusselmerkmale erbrqacht, die eine Unterscheidung der aus dem Mittelmeer stmmenden Arten der Xanthidae erleichtern. Als Ergebnis dieser Untersuchungen kann gesagt werden, dass Xantho granulicarpus Forest, 1953 aus dem Mittelmeer klar von Xantho hydrophilus (Herbst, 1790) aus dem Atlantik unterschieden ist und dass Monodaeus guinotae Forest, 1976 identisch mit Monodaeus couchii (Couch, 1851) ist. Fur die untersuchten Arten werden zusatzliche Verbreitungsangaben gemacht und ein Bestimmungsschlussel auf der Grundlage ausgewahlter konstanter Merkmale bereitgestellt. , A review of the relevant literature and a comparative study of adequate samples from the Mediterranean Sea and the Atlantic Ocean, revealed new key morphological features that facilitate a distinction of the Mediterranean species of Xanthidae. Based on this study, the Mediterranean Xantho granulicarpus Forest, 1953 is clearly distinguished from the Atlantic Xantho hydrophilus (Herbst, 1790) and Monodaeus guinotae Forest, 1976 is identical with Monodaeus couchii (Couch, 1851). For the species studied, additional information is given about their geographical distribution, as well as an identification key based on selected, constant features. Literaturstudien und vergleichende Untersuchungen geeigneter Proben aus dem Mittelmeer und dem Atlantischen Ozean haben neuen morphologische Schlusselmerkmale erbrqacht, die eine Unterscheidung der aus dem Mittelmeer stmmenden Arten der Xanthidae erleichtern. Als Ergebnis dieser Untersuchungen kann gesagt werden, dass Xantho granulicarpus Forest, 1953 aus dem Mittelmeer klar von Xantho hydrophilus (Herbst, 1790) aus dem Atlantik unterschieden ist und dass Monodaeus guinotae Forest, 1976 identisch mit Monodaeus couchii (Couch, 1851) ist. Fur die untersuchten Arten werden zusatzliche Verbreitungsangaben gemacht und ein Bestimmungsschlussel auf der Grundlage ausgewahlter konstanter Merkmale bereitgestellt. ]

Crassophyllum thessalonicae sp.n. (Octocorallia, Pennatulacea), from the Aegean Sea

A new pennatulacean species, Crassophyllum thessalonicae sp.n. is described from the Mediterranean (North Aegean Sea). This is the first record of a Crassophyllum Tixier‐Duri vault, 1961 species from the Mediterranean Sea. The differences between the new species and C. cristatum Tixier‐Durivault, 1961, the other known species of the genus, are discussed, and the genus Crassophyllum is critically compared with the other two related genera Pteroeides Herklots, 1858 and Sarcoptilus Gray, 1848.