Taxonomic status and origin of the Egyptian weasel (Mustela subpalmata) inferred from mitochondrial DNA.

The Egyptian weasel (Mustela subpalmata) is a small mustelid with a distribution restricted to the lower Nile Valley and the Nile Delta. Traditionally considered a subspecies of the least weasel (M. nivalis), it is currently recognized as a separate species based on morphology. Here we present the first genetic assessment of the taxonomic status of the Egyptian weasel by comparing mitochondrial DNA (Cytochrome b gene and control region) sequences to those of least weasels from the western Palearctic, with a focus on the Mediterranean region. Our results provide no evidence to support the view that the Egyptian weasel is genetically distinct from the least weasel, as we found that, for both Cytochrome b and control region, haplotypes were shared between the two taxa. Specifically, the Cytochrome b and control region haplotypes detected in the Egyptian weasel were also present in M. nivalis from Turkey and Malta, two populations genetically analysed here for the first time. Our results suggest that the Egyptian weasel is distinct from the least weasel populations currently living in the Maghreb, which were inferred to be the result of an earlier colonization of North Africa, but the genetic data alone do not allow us to determine whether the Egyptian weasel is native or introduced. Nevertheless, the observed genetic patterns, together with the weasel fossil record in Israel and the unique commensal lifestyle of the Egyptian weasel, are consistent with the hypothesis that the Egyptian population is a relict of past range expansion from the Levant into Egypt. We suggest that the large size and characteristic sexual dimorphism of the Egyptian weasel are likely to represent ecotypic variation, but genomic studies are required to clarify the extent of its functional genetic divergence.

Evolutionary history of the Maltese wall lizard Podarcis filfolensis: insights on the 'Expansion­Contraction' model of Pleistocene biogeography.

The expansion­contraction (EC) model predicts demographic and range contraction of temperate species during Pleistocene glaciations as a consequence of climate-related habitat changes, and provides a paradigm for explaining the high intraspecific diversity found in refugia in terms of long-term demographic stability. However, recent evidence has revealed a weak predictive power of this model for terrestrial species in insular and coastal settings. We investigated the Pleistocene EC dynamics and their evolutionary consequences on temperate species using the Maltese archipelago and its endemic lizard Podarcis filfolensis as a model system. The evolutionary and demographic history of P. filfolensis as inferred from mitochondrial and nuclear sequences data does not conform to the EC model predictions, supporting (i) demographic and spatial stability or expansion, rather than contraction, of the northern and southern lineages during the last glacial period; and (ii) a major role for allopatric differentiation primed by sea-level dynamics, rather than prolonged demographic stability, in the formation of the observed genetic diversity. When combined with evidence from other Mediterranean refugia, this study shows how the incorporation of Pleistocene sea-level variations in the EC model accounts for a reverse demographic and range response of insular and coastal temperate biotas relative to continental ones. Furthermore, this cross-archipelago pattern in which allopatric diversity is formed and shaped by EC cycles resembles that seen between isolated populations within mainland refugia and suggests that the EC model, originally developed to explain population fluctuations into and out-of refugia, may be appropriate for describing the demographic and evolutionary dynamics driving the high genetic diversity observed in these areas.

Non-indigenous species refined national baseline inventories: A synthesis in the context of the European Union's Marine Strategy Framework Directive.

Refined baseline inventories of non-indigenous species (NIS) are set per European Union Member State (MS), in the context of the Marine Strategy Framework Directive (MSFD). The inventories are based on the initial assessment of the MSFD (2012) and the updated data of the European Alien Species Information Network, in collaboration with NIS experts appointed by the MSs. The analysis revealed that a large number of NIS was not reported from the initial assessments. Moreover, several NIS initially listed are currently considered as native in Europe or were proven to be historical misreportings. The refined baseline inventories constitute a milestone for the MSFD Descriptor 2 implementation, providing an improved basis for reporting new NIS introductions, facilitating the MSFD D2 assessment. In addition, the inventories can help MSs in the establishment of monitoring systems of targeted NIS, and foster cooperation on monitoring of NIS across or within shared marine subregions.

Improving the Conservation of Mediterranean Chondrichthyans: The ELASMOMED DNA Barcode Reference Library.

Cartilaginous fish are particularly vulnerable to anthropogenic stressors and environmental change because of their K-selected reproductive strategy. Accurate data from scientific surveys and landings are essential to assess conservation status and to develop robust protection and management plans. Currently available data are often incomplete or incorrect as a result of inaccurate species identifications, due to a high level of morphological stasis, especially among closely related taxa. Moreover, several diagnostic characters clearly visible in adult specimens are less evident in juveniles. Here we present results generated by the ELASMOMED Consortium, a regional network aiming to sample and DNA-barcode the Mediterranean Chondrichthyans with the ultimate goal to provide a comprehensive DNA barcode reference library. This library will support and improve the molecular taxonomy of this group and the effectiveness of management and conservation measures. We successfully barcoded 882 individuals belonging to 42 species (17 sharks, 24 batoids and one chimaera), including four endemic and several threatened ones. Morphological misidentifications were found across most orders, further confirming the need for a comprehensive DNA barcoding library as a valuable tool for the reliable identification of specimens in support of taxonomist who are reviewing current identification keys. Despite low intraspecific variation among their barcode sequences and reduced samples size, five species showed preliminary evidence of phylogeographic structure. Overall, the ELASMOMED initiative further emphasizes the key role accurate DNA barcoding libraries play in establishing reliable diagnostic species specific features in otherwise taxonomically problematic groups for biodiversity management and conservation actions.

Influence of tuna penning activities on soft bottom macrobenthic assemblages.

The influence of tuna penning on soft bottom habitat present in the vicinity of tuna pens and at distances 200 m and 1.5 km away, was assessed by comparing attributes of macroinvertebrate assemblages and sediment quality before (November 2000, March 2001) and after (November 2001, April 2002) initiation of the activity. Results from November 2001 indicated a significant increase in sediment organic carbon and organic nitrogen, and a non-significant increase in the abundance of Capitellidae in the vicinity of the cages. Similar results were obtained 200 m from the cages but not 1.5 km away, where the only change was a significant increase in organic nitrogen in sediment. Results from April 2002 indicated no significant change in sediment organic carbon and organic nitrogen, however, mean sediment grain size decreased significantly in the immediate vicinity of the cages. Changes in attributes of the benthic assemblages and sediment resulted from accumulation of uneaten feed-fish on the seabed.