Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities.

Histopathological and ultrastructural investigations were conducted on 36 tench, Tinca tinca (L.), from Lake Trasimeno (Italy). The gills, intestine, liver, spleen, kidney and heart of 21 individuals were found to harbour an extensive infection of larvae of an unidentified digenean trematode. The eyes, gonads, swim bladder and muscles were uninfected. The parasites in each tissue type were embedded in a granulomatous proliferation of tissue, forming a reactive fibroconnective capsule around each larva. Most of the encysted larvae were metacercariae, in a degenerative state, but on occasion some cercariae were found. Many of the granulomas were either necrotic or had a calcified core. Within the granuloma of each, the occurrence of granulocytes, macrophages, rodlet cells and pigment-bearing macrophage aggregates was observed. Hearts bore the highest parasitic infection. Whilst the presence of metacercariae within the intestine was found positioned between the submucosa and muscle layers, metacercariae in the liver were commonly found encysted on its surface where the hepatocytes in close contact with the granuloma were observed to have electron-lucent vesicles within their cytoplasm. Metacercariae encysting adjacent to the cartilaginous rods of gill filaments were seen to elicit a proliferation of the cartilage from the perichondrium. Rodlet cells, neutrophils and mast cells were frequently observed in close proximity to, and within, infected gill capillaries. Given the degenerated state of most granulomas, a morphology-based identification of the enclosed digeneans was not possible.

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The aim of this study was to gather more informations about the biological characteristics of Procambarus clarkii and to investigate the reasons of its rapid expansion in Lake Trasimeno. Specimens of both sexes (544 males and 624 females) were collected from October 2000 to November 2001. During the sampling period physical factors such as water temperature and hydrologic level of Lake Trasimeno were recorded. The study was conducted monthly in order to assess this species' reproductive period. 1,168 specimens were analyzed for colour, sex, weight, and length. The sexual maturation of gonads was investigated in females. The results of this study evidenced that the population is in expansion, showing that Lake Trasimeno is an optimal habitat for this species. Key-words:Red-swamp crayfish, Procambarus clarkii, growth, reproduction, Lake Trasimeno. 1 168 exemplaires ont été analysés selon la couleur, le sexe, le poids, la longueur et le degré de maturité des gonades a été relevé pour les femelles. Les résultats de cette étude ont mis en évidence que la population de Procambarus clarkii est en expansion et il semble que le Lac Trasimeno soit un habitat optimal pour cette espèce. BIOLOGIE DE PROCAMBARUS CLARKII (GIRARD, 1852) DANS LE LAC TRASIMENO RÉSUMÉ