In the central Mediterranean Sea, gut contents and feces of 95 turtles captured by bottom trawlers and pelagic longliners fishing in neritic and oceanic areas, respectively, were examined. Benthic prey were more abundant than pelagic, a probable bias due to the higher digestibility of the latter. Animal and plant taxa belonging to 12 Phyla and 20 Classes were observed, with 63 new records of prey species, and Malacostraca, Gastropoda, and Echinoidea were the most commonly occurring animal classes. Results showed a highly opportunistic foraging behavior by the turtles on both live and dead material in the epipelagic zone as well as on all types of seafloor. Benthic taxa were found in turtles as small as 26 cm curved carapace length (CCL), indicating an early use of benthic resources, and also among turtles over a wide size range caught by pelagic longliners. The lack of evidence of a strict oceanic/ pelagic stage and of a clear habitat shift in the observed size range (25 to 80.3 cm CCL), when considered together with other recent findings, challenges the current ontogenetic model of life history for the species. A relaxed model is proposed, with an early short obligate epipelagic stage due to limited diving capacity, followed by the main opportunistic amphi-habitat stage, with a tendency to prefer benthic prey as turtles grow and their benthic foraging efficiency improves. Under this model, temporary or permanent association or fidelity to specific oceanic or neritic zones would vary among individuals or populations according to food availability and oceanographic features in the foraging or migratory areas. KEY WORDS: Sea turtle · Caretta caretta · Diet · Life history · Mediterranean Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 372: [265][266][267][268][269][270][271][272][273][274][275][276] 2008 Mediterranean basin (Margaritoulis et al. 2003). In particular, the area between Sicily (Italy) and Africa is considered among the most important areas for loggerheads and this is where pelagic longliners and bottom trawlers capture high numbers of turtles (Casale et al. 2007a).Diet data from different neritic areas of the basin show markedly different compositions of benthic taxa, an indication of opportunistic feeding (Laurent & Lescure 1994, Godley et al. 1997, Tomas et al. 2001. However, the ecology of loggerhead turtles in the basin is still poorly known. Laurent et al. (1998) hypothesized a transitional stage between the strictly oceanic and neritic stages, in which loggerhead turtles would feed mainly on pelagic prey but also on benthic prey, but this has not yet been adequately investigated through diet analyses. This is not a simple task, since loggerhead turtles in the neritic stage are known to feed throughthe whole water column (Bolten 2003), so that finding pelagic and benthic prey in the same sample (e.g. Tomas et al. 2001) is not proof of a transitional stage.Small loggerhead turtles (minimum size: 29.5 and 22 cm respectively; Casale et al....

Aim We looked at the biogeographical patterns of Oniscidean fauna from the small islands of the Mediterranean Sea in order to investigate the species-area relationship and to test for area-range effects.Location The Mediterranean Sea.Methods We compiled from the literature a data set of 176 species of Oniscidea (terrestrial isopods) distributed over 124 Mediterranean islands. Jaccard's index was used as input for a UPGMA cluster analysis. The species-area relationship was investigated by applying linear, semi-logarithmic, logarithmic and sigmoid models. We also investigated a possible 'small island effect' (SIE) by performing breakpoint regression. We used a cumulative and a sliding-window approach to evaluate scale-dependent area-range effects on the log S/log A regression parameters.Results Based on similarity indexes, results indicated that small islands of the Mediterranean Sea can be divided into two major groups: eastern and western. In general, islands from eastern archipelagos were linked together at similarity values higher than those observed for western Mediterranean islands. This is consistent with a more even distribution of species in the eastern Mediterranean islands. Separate archipelagos in the western Mediterranean could be discriminated, with the exception of islets, which tended to group together at the lowest similarity values regardless of the archipelago to which they belong. Islets were characterized by a few common species with large ranges. The species-area logarithmic model did not always provide the best fit. Most continental archipelagos showed very similar intercepts, higher than the intercept for the Canary island oceanic archipelago. Sigmoid regression returned convex curves. Evidence for a SIE was found, whereas area-range effects that are dependent on larger scale analyses were not unambiguously supported.Main conclusions The Oniscidea fauna from small islands of the Mediterranean Sea is highly structured, with major and minor geographical patterns being identifiable. Some but not all of the biogeographical complexity can be explained by interpreting the different shapes of species-area curves. Despite its flexibility, the sigmoid model tested did not always provide the best fit. Moreover, when the model did provide a good fit the curves looked convex, not sigmoid. We found evidence for a SIE, and minor support for scale-dependent area-range effects.

The subterranean Isopods belonging to the genus Stenasellus have an interesting disjunct distribution in the peri-Tyrrhenian area with morphologically closely related taxa occurring in Sardinia, Corsica, Tuscany and in the Pyrenees phreatic and interstitial waters. Because the dispersal capacities of these organisms are limited, their distribution has been associated traditionally with the tectonic events leading to the separation of the Sardinia-Corsica microplate from the Pyrenees and its subsequent movement towards the Italian peninsula. We sequenced a fragment of the mtDNA cytochrome oxidase I gene (COI) for multiple populations of the S. racovitzai species-group (Corsica, Sardinia, Tuscany) and S. virei (Pyrenees). We found that multiple phylogenetic analyses always gave the same topology, which is consistent with the genetic relations found using allozyme data, and with the palaeogeography of the area. The molecular data suggest that a combination of vicariance and dispersal events explain most effectively the present distribution pattern of these organisms. We also calculated COI rates and calibrated them against absolute time, taking advantage of the availability of two geologically based time estimates. Rates on all substitutions are similar to those published for other crustaceans for the same COI fragment, including taxonomically and ecologically distant groups. Rates on third codon positions or on transversions are generally lower than those found in other crustaceans.

1.Spatio-temporal distribution and anthropogenic mortality factors were investigated in loggerhead turtles (Caretta caretta) found stranded or floating in the waters around Italy. A total of 5938 records for the period 1980-2008 were analysed concerning loggerhead turtles measuring from 3.8 to 97 cm curved carapace length (mean: 48.3 cm).2.Results highlighted the following conservation issues: (i) in the study area, anthropogenic mortality is higher than natural mortality; (ii) interaction with fisheries is by far the most important anthropogenic mortality factor; (iii) longlines are an important mortality factor in the southern areas; (iv) trawlers are the cause of high numbers of dead strandings in the north Adriatic; (v) entanglement in ghost-gear or in other anthropogenic debris affects high numbers of turtles; and (vi) boat strikes are an important source of mortality in most areas but mostly in the warm seasons.3.Results also indicate that: (vii) the north Adriatic is the area with the highest turtle density; and (viii) the south Adriatic and to a lesser extent the surrounding areas of the north Adriatic and the Ionian, are important developmental areas for loggerhead turtles in the first years of life.4.Italy is in the centre of the Mediterranean Sea and borders major foraging areas for the loggerhead turtles in the region, and these results confirm previous concerns about the level of anthropogenic mortality in Italian waters. © 2010 John Wiley & Sons, Ltd

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