Observations about surface behaviour of the great white shark Carcharodon carcharias (L.) in presence of passive preys at Dyer Island (Southafrica)

During 4 study expeditions in SouthAfrica, performed in 2000, 2003, 2004 and 2005, observations about surface predatory behaviour of the Great White Shark in presence of passive preys were made. Observations were carried out by Unlimited Shark Diving boats and by cage diving around Dyer Island, about 5 miles far from Gansbaai. During the 27 observation days were identified 78 different specimens, that exhibited 8 different behaviours. The Great White Shark population observed around Dyer island shows a greater variety of behaviours than the population studied along the California coasts

Addressing conservation measures through fine-tuned species distribution models for an Italian endangered endemic anuran

Climate and land cover changes are the two most important stressors causing the decline of amphibians' populations worldwide. Within the Mediterranean area, one of the global biodiversity hotspots, the endemic Italian yellow-bellied toad (Bombina pachypus) suffered the same fate, as the decreases and local extinctions proved over time. Since the need to preserve this Apennine endemic species is evident, we take advantage of a novel approach combining climate-based ecological niche models and post-modelling GIS techniques (i.e., the weighted overlay framework) to produce finer species distribution models for B. pachypus. In doing so, we coupled climate variables with topographic-, hydrologic-, and habitat-related predictors, sharpening the potential species' distribution at its whole range scale. Our findings show a latitudinal subdivision in predicted suitability: Central Apennines populations are expected to suffer more than the Northern ones, with considerable potential future losses of genetic diversity. On the contrary, Southern Apennines' suitability is predicted to remain stable over time, preserving the vast di-versity. When assessing the coverage that protected areas offer to the locations of suitable habitats for B. pachypus, the protected sites of the Central Apennines result in slightly less suitable con-servation areas than those in the Northern and Southern Apennines. The overall protected areas coverage is currently low (similar to 20%) and predicted in the future to narrow towards medium suit-ability values, except in Southern Apennines, where an increase is inferred. In light of our spatially-explicit results, we suggest that a national-scale conservation strategy should consider different management options according to the sub-territories that our analyses highlighted. Our coupled "weighted modelling - spatialised genetic inference" approach permits us to support different conservation policies at all spatial scales, capitalising on relatively few input data. Also, in-depth spatial analyses should be performed to support effective protection strategies and management for the conservation stakeholders

New Mediterranean Biodiversity Records (April 2015)

The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of native and alien species respectively. The new records of native fish species include: the slender sunfish Ranzania laevis and the scalloped ribbonfish Zu cristatus in Calabria; the Azores rockling Gaidropsarus granti in Calabria and Sicily; the agujon needlefish Tylosu¬rus acus imperialis in the Northern Aegean; and the amphibious behaviour of Gouania willdenowi in Southern Turkey. As regards molluscs, the interesting findings include Ischnochiton usticensis in Calabria and Thordisa filix in the bay of Piran (Slovenia). The stomatopod Parasquilla ferussaci was collected from Lesvos island (Greece); the isopod Anilocra frontalis was observed parasit¬izing the alien Pteragogus trispilus in the Rhodes area. The asteroid Tethyaster subinermis and the butterfly ray Gymnura altavela were reported from several localities in the Greek Ionian and Aegean Seas.The new records of alien species include: the antenna codlet Bregmaceros atlanticus in Saronikos Gulf; three new fish records and two decapods from Egypt; the establishment of the two spot cardinal fish Cheilodipterus novemstriatus and the first record of the marble shrimp Saron marmoratus in semi-dark caves along the Lebanese coastline; the finding of Lagocephalus sceleratus, Sargocentron rubrum, Fistularia commersonii and Stephanolepis diaspros around Lipsi island (Aegean Sea, Greece); the decapod Penaeus Hathor in Aegean waters; the decapod Penaeus aztecus and the nudibranch Melibe viridis in the Dodecanese islands; the finding of Pinctada imbricata radiate in the Mar Grande of Taranto (Ionian Sea, Italy) and the Maliakos Gulf (Greece)

New Mediterranean Marine biodiversity records

Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters); the nemertean Amphiporus allucens (Iberian Peninsula, Spain); the salp Salpa maxima (Syria); the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece); the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy); Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey); the reticulated leatherjack Stephanolepis diaspros and the halacarid Agaue chevreuxi (Sea of Marmara, Turkey); the slimy liagora Ganonema farinosum, the yellowstripe barracuda Sphyraena chrysotaenia, the rayed pearl oyster Pinctada imbricata radiata and the Persian conch Conomurex persicus (south-eastern Kriti, Greece); the blenny Microlipophrys dalmatinus and the bastard grunt Pomadasys incisus (Ionian Sea, Italy); the brown shrimp Farfantepenaeus aztecus (north-eastern Levant, Turkey); the blue-crab Callinectes sapidus (Corfu, Ionian Sea, Greece). In addition, the findings of the following rare species improve currently available biogeographical knowledge: the oceanic pufferfish Lagocephalus lagocephalus (Malta); the yellow sea chub Kyphosus incisor (Almuñécar coast of Spain); the basking shark Cetorhinus maximus and the shortfin mako Isurus oxyrinchus (north-eastern Levant, Turkey)

New Mediterranean biodiversity records (March 2016)

In this Collective Article on “New Mediterranean Biodiversity Records”, we present additional records of species found in the Mediterranean Sea. These records refer to eight different countries mainly throughout the northern part of the basin, and include 28 species, belonging to five Phyla. The findings per country include the following species: Spain: Callinectes sapidus and Chelidonura fulvipunctata; Monaco: Aplysia dactylomela; Italy: Charybdis (Charybdis) feriata, Carcharodon carcharias, Seriola fasciata, and Siganus rivulatus; Malta: Pomacanthus asfur; Croatia: Lagocephalus sceleratus and Pomadasys incisus; Montenegro: Lagocephalus sceleratus; Greece: Amathia (Zoobotryon) verticillata, Atys macandrewii, Cerithium scabridum, Chama pacifica, Dendostrea cf. folium, Ergalatax junionae, Septifer cumingii, Syphonota geographica, Syrnola fasciata, Oxyu- richthys petersi, Scarus ghobban, Scorpaena maderensis, Solea aegyptiaca and Upeneus pori; Turkey: Lobotes surinamensis, Ruvettus pretiosus and Ophiocten abyssicolum. In the current article, the presence of Taractes rubescens (Jordan & Evermann, 1887) is recorded for the first time in the Mediterranean from Italy. The great contribution of citizen scientists in monitoring biodiversity records is reflected herein, as 10% of the authors are citizen scientists, and contributed 37.5% of the new findings.peer-reviewe

Behavioural responses of white sharks to specific baits during cage diving ecotourism

This study describes the effect of different baits on the attraction, surface behaviour and conditioning of white sharks Carcharodon carcharias during local ecotourism activities. The sightings, behaviours, and pictures used for photographic identification were obtained during August to November 2012-2014 onboard tourist boats in Guadalupe Island, Mexico. Four types of baits were used: (1) frozen bait; (2) frozen bait and natural chum; (3) fresh fish bait; and (4) mackerel bags. Data were analysed according to sex, maturity and the total of sharks using 6,145 sightings of 121 white sharks. The type of bait showed no significant difference on the effectiveness to attracting sharks. Ethological analysis showed that the type of bait had a significant effect on the shark's surface behaviour during its interactions with boats. Natural chum and fresh baits showed short term behavioural patterns constituted by increased number of violent interactions with the bait, while the frozen bait did not generate a defined behavioural pattern. Conditioning of white sharks was determined by the number of interactions and the consumption frequency of the bait. Fifty nine percent of sharks (n=41) showed no conditioning, 36% (n=25) showed a low risk and only 5% (n=3) were found to have a high risk of conditioning. The results suggest that current ecotourism has no effect on the conditioning of the white sharks, and that all baits have a similar effectiveness for attracting the sharks. However, a different behavioural pattern was observed when fresh bait and chum were used, which could increase the potential of accidents during ecotourism

Summer Distribution, Relative Abundance and Encounter Rates of Cetaceans in the Mediterranean Waters off Southern Italy (Western Ionian Sea and Southern Tyrrhenian Sea)

In summer 2010 and summer 2011, weekly cetacean surveys were undertaken in "passing mode", using ferries as platform of opportunity, along the "fixed line transect" between Catania and Civitavecchia (Southern Italy). Of the 20 species of cetaceans confirmed for the Mediterranean sea, 8 were sighted within the survey period: 7 species represented by Mediterranean subpopulations (Balaenoptera physalus, Physeter macrocephalus, Stenella coeruleoalba, Delphinus delphis, Grampus griseus, Tursiops truncatus and Ziphius cavirostris) and one considered visitor (Steno bredanensis). We had a total of 220 sightings during the 2010 and a total of 240 sightings in the 2011. The most frequent species was S. coeruleoalba. By the comparison of the data from the two sampling seasons, a significant increase of D. delphis sightings and a decrease of sightings of B. physalus and P. macrocephalus was observed from 2010 to 2011. While all the other species were observed in both sampling seasons, Z. cavirostris and Steno bredanensis were observed only during 2011. The presence of mixed groups of odontocetes was documented too: we sighted groups composed by S. coeruleoalba and D. delphis, by S. coeruleoalba and T. truncatus, and by S. coeruleoalba and G. griseus. The results of this research add useful information on cetacean species in a very poorly known area and highlight the need to standardize large scale and long term monitoring programs in order to detect variation in presence, abundance and distribution of cetaceans populations and understand the effect of anthropogenic factors

Trace elements and isotopes analyses on historical samples of white sharks from the Mediterranean Sea

The white shark Carcharodon carcharias has been present in the Mediterranean Sea since 3.2 million years ago. Nevertheless, the current population shows a low genetic variability suggesting an endangered small population, on which there is scarce information regarding ecotoxicology or trophic ecology. Given that white shark's sightings are rare in the Mediterranean and the possibility of obtaining samples is highly limited, the aim of this research was to provide general information regarding the concentration of trace elements and stable isotopes (delta N-15 and delta C-13). Laboratory analyses were performed on 18 and 12 subsamples from two different white sharks' vertebrae obtained from two adult specimens caught in 1987, in Favignana Island, Italy. Perforations were made along the vertebrae to describe both trace elements and stable isotopes at different life stages. A total of 38 trace elements were analysed, in which the highest concentrations were found in Fe, Sr, U, Pb, and Zn. The fluctuations of these elements during the ontogeny of both individuals could have been related to changes in diet and environment, although the specific origin remains unknown. Regarding stable isotopes, the vertebrae from the male showed an isotopic range from 9.6 parts per thousand to 10.8 parts per thousand (delta N-15) and from -16.5 parts per thousand to -13.0 parts per thousand (delta C-13) with a mean +/- SD value of 10.3 +/- 0.4 parts per thousand for delta N-15 and -14.6 +/- 1.3 parts per thousand for delta C-13; whereas the female vertebrae had an isotopic range from 9.8 parts per thousand to 11.1 parts per thousand (delta N-15) and from -16.9 parts per thousand to -15.0 parts per thousand (delta C-13), with a mean +/- SD value of 10.8 +/- 0.6 parts per thousand for delta N-15 and -15.8 +/- 0.8 parts per thousand for delta C-13. There were no significant delta N-15 differences (U = 6, p = 0.07346) between the two individuals. However, there were just significant differences in delta C-13 (t = -1.8, p = 0.049256), which could suggest sexual segregation in terms of habitat use and feeding habits