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The structure and composition of Mediterranean biodiversity has changed significantly. So far, in Montenegrin coastal waters, nine new non-native species have been recorded: Tylosurus acus imperialis, Caranx crysos, Siganus luridus, Fistularia commersonii, Stephanolepis diaspros, Sphoeroides pachygaster, Lagocephalus sceleratus, Callinectes sapidus and Farfantepanaeus aztecus. Allochthonous species are starting to compete for food and space and leading to habitat degradation, socio-economic impacts and can hybridise with the native species. Natural factors and human activities have enabled the arrival of non-native species into the Adriatic Sea. Four of the species are Lessepsian immigrants, which arrived via the Suez Canal, but five others were introduced from the Atlantic Ocean, through the Strait of Gibraltar. Analysis using the Marine Fish Invasiveness Screening Kit (MFISK), Aquatic Invasiveness Screening Kit (AS-ISK) and Receiver operating characteristic (ROC) showed a calibration threshold of 22.5 for MFISK, a BRA (Basic Risk Assessment) score of 34 and a CCA (Climate Change Assessment) score of 46. A measure of the accuracy of the calibration analysis is the area under the ROC curve (AUC). Two species were characterised as non-invasive: Tylosurus acus imperialis and Caranx crysos, but five others were characterised as invasive and covered by the categories from moderate to high-risk., Struktura i sastav bioraznolikosti Sredozemlja značajno su se promijenili. Do sada je u crnogor- skom primorju zabilježeno devet novih ne-nativnih vrsta: Tylosurus acus imperialis, Caranx crysos, Siganus luridus, Fistularia commersonii, Stephanolepis diaspros, Sphoeroides pachygaster, Lagocephalus sceleratus, Callinectes sapidus i Farfantepanaeus aztecus. Alohtone vrste počinju se natjecati za hranu i prostor i dovode do degradacije staništa, socio-ekonomskih učinaka i mogu hibridizirati s autohtonim vrstama. Prirodni čimbenici i ljudske aktivnosti omogućili su dolazak ne- nativnih vrsta u Jadransko more. Četiri vrste su lesepsijski imigranti, koji su stigli preko Sueskog kanala, ali pet drugih uneseno je iz Atlantskog oceana, kroz Gibraltarski tjesnac. Analiza korištenjem programa MFISK (Marine Fish Invasiveness Screening Kit), AS-ISK (Aquatic Invasiveness Screen- ing Kit) i ROC (Receiver operating characteristic) pokazala je prag kalibracije od 22,5 za MFISK, BRA (Basic Risk Assessment)) rezultat od 34 i CCA (Climate Change Assessment) ocjenu od 46. Mjera točnosti kalibracijske analize je površina ispod ROC krivulje (AUC). Dvije vrste okarakter- izirane su kao neinvazivne: Tylosurus acus imperialis i Caranx crysos, no pet drugih okarakter- izirano je kao invazivno i obuhvaćeno kategorijama od umjerenog do visokog rizika.

The blue shark belongs to the group of the most widespread pelagic sharks in the world. It inhabits the pelagic zone of almost all warm and temperate seas and oceans. As it is one of the most abundant shark species, it is frequently caught in different types of fishing gear operated in the pelagic zone. This study provides the first data on the reproduction of this species in Montenegrin waters (in the Southeastern Adriatic Sea). Six newborn blue sharks were found during our field excursions. For three of them, detailed morphometric measurements are presented. Alongside the newborns, a gravid female was also recorded. The data was collected in the period from April to October 2017. According to the published literature and the data presented in this paper, species reproduction is likely to be seasonal. A review of the areas where the specimens were recorded was carried out in order to infer if the adult females choose them specifically as their parturition grounds., Pas modrulj pripada grupi najviše rasprostranjenih pelagičnih morskih pasa na svijetu. Obitava u pelagičnoj zoni gotovo svih umjerenih i toplih mora i oceana. Premda je jedan od najčešćih morskih pasa, često se lovi različitim ribolovnim alatima koji se koriste u pelagijalu. Ovim istraživanjem sakupljeni su prvi podaci o reprodukciji ove vrste u Crnoj Gori (Jugoistočni Jadran). Tijekom terenskih istraživanja, evidentirano je šest tek rođenih jedinki. Za tri jedinke, prikazane su detaljne morfo-metrijske mjere. Pored spomenutih jedinki, zabilježena je i gravidna ženka ove vrste. Svi podaci su sakupljeni u razdoblju od travnja do listopada 2017. Prema do sada objavljenoj literaturi i ovdje prikazanim podacima, moguće je da je reprodukcija ove vrste sezonska. Izvršen je i pregled lokaliteta na kojima su jedinke pronađene, kako bi se utvrdilo biraju li ih ženke kao mjesta za rađanje mladih.