Results of the AlienFish project – monitoring and study of rare and non-indigenous fish species in Italian waters – collected through citizen science in 2018 are here reported. Overall, 36 ...observations of 21 fish species belonging to 17 families were provided from the central and southern sectors of Italian seas. Our findings highlight the effectiveness of involving sea users in the detection of fish species of both indigenous and non-indigenous origin. Professional fishermen were particularly effective in providing information on rare deep-water and open-water fishes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This checklist of the Mediterranean fishes of Israel enumerates 469 species which is an addition of 62 species since the previous checklist of 2005. This new checklist includes 58 Condrichthys and ...411 Osteicthys species. Most newly-recorded species are of Red Sea origin (Lessepsian migrants)-38 species, 25 species are from previously poorly investigated habitats, mainly deep water, while two species reached the Mediterranean most likely by ballast water and two are aquaculture escapees. The dramatic increase in the number of Lessepsian migrants (an average of 2.5 species per year) is most likely due to the increased water influx between the Red Sea and the Mediterranean, following the recent opening of the new parallel, 72 km, "new canal" and the enlargement of other parts of the Suez Canal.
Human activities, such as shipping, aquaculture, and the opening of the Suez Canal, have led to the introduction of nearly 1,000 alien species into the Mediterranean Sea. We investigated how human ...activities, by providing pathways for the introduction of alien species, may shape the biodiversity patterns in the Mediterranean Sea. Richness of Red Sea species introduced through the Suez Canal (Lessepsian species) is very high along the eastern Mediterranean coastline, reaching a maximum of 129 species per 100 km2, and declines towards the north and west. The distribution of species introduced by shipping is strikingly different, with several hotspot areas occurring throughout the Mediterranean basin. Two main hotspots for aquaculture-introduced species are observed (the Thau and Venice lagoons). Certain taxonomic groups were mostly introduced through specific pathways – fish through the Suez Canal, macrophytes by aquaculture, and invertebrates through the Suez Canal and by shipping. Hence, the local taxonomic identity of the alien species was greatly dependent on the dominant maritime activities/interventions and the related pathways of introduction. The composition of alien species differs among Mediterranean ecoregions; such differences are greater for Lessepsian and aquaculture-introduced species. The spatial pattern of native species biodiversity differs from that of alien species: the overall richness of native species declines from the north-western to the south-eastern regions, while the opposite trend is observed for alien species. The biodiversity of the Mediterranean Sea is changing, and further research is needed to better understand how the new biodiversity patterns shaped by human activities will affect the Mediterranean food webs, ecosystem functioning, and the provision of ecosystem services.
The rate of biological invasions is steadily increasing, with major ecological and economic impacts accounting for billions of dollars in damage as a result. One spectacular example is the western ...Atlantic invasion by lionfishes. In the Mediterranean Sea, invasions from the Red Sea via the Suez Canal (termed Lessepsian invasions) comprise more than 100 fish species, including a recent invasion by lionfish. In light of the devastating effects of lionfish in the Caribbean Sea, understanding the dynamics of Mediterranean lionfish invasion is crucial. The Lessepsian lionfish invasion started in 2012, and rapidly spread to the central Mediterranean. Here, we used thousands of RAD seq genomic markers to study the population dynamics of this invasion. While we did not find a reduction in genetic diversity between source (Red Sea) and invasive (Mediterranean) populations (i.e., bottleneck effects), we found evidence of population structure within the invasive range in the Mediterranean Sea. We found that loci that are potentially under selection may play an important role in invasion success (in particular, genes involved in osmoregulation and fin spine sizes). Genomic approaches proved powerful in examining the ecological and evolutionary patterns of successful invaders and may be used as tools to understand and potentially mitigate future invasions.
Lionfish are well‐known for having invaded the Caribbean with devastating ecological effects. Here we study the genomics of a recent invasion of lionfish in the Mediterranean, coming from the Red Sea via the Suez Canal. We found that genetic diversity has not declined during the invasion phase, and some genes potentially under selection may have contributed to the invasion success.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The present review critically assesses the records of cephalopods that have entered the Mediterranean Sea in the last few decades. It includes 13 species, namely Sepia dollfusi, Stoloteuthis ...leucoptera, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. and Tremoctopus gracilis. The presence of Sepia pharaonis needs to be confirmed, whereas that of Sepia gibba and Spirula spirula is excluded. The arrivals from the Atlantic Ocean through the Strait of Gibraltar are related to the entrance surface current, which either carried passively planktonic paralarvae or favoured in some other way the entrance of subadult and adult stray specimens. As a matter of fact, all Atlantic cephalopods are pelagic oegopsid squids, with the exception of the nekto-benthic sepiolid S. leucoptera; all of them have been found only in the western Mediterranean basin. None of them seemingly established a stable population there, apart from the latter species. On the contrary, the cephalopods entering the Mediterranean from the Red Sea through the Suez Canal (Lessepsian migrants) lead a benthic mode of life. At least two of them, namely S. lessoniana and Amphioctopus sp., set up stable populations in the eastern basin. Lastly the occurrences of the pelagic octopod T. gracilis are ascribed, in the literature, to human-mediated transfer.
U ovom radu autori kritički procjenjuju nalaze glavonožaca koji su ušli u Sredozemno more u posljednjih nekoliko desetljeća, što uključuje 13 vrsta, a to su: Sepia dollfusi, Stoloteuthis leucopte-ra, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. i Tremoctopus gracilis. Prisutnost vrste Sepia pharaonis treba biti potvrđena, dok je prisutnost Sepia gibba i Spirula spirula isključena.
Dolasci vrsta iz Atlantskog oceana kroz Gibraltarski tjesnac povezani su s ulaznom površinskom strujom koja je nosila pasivno planktonske paralarve ili je na neki drugi način favorizirala ulaz subadultnih i odraslih zalutalih primjeraka. Zapravo su svi atlantski glavonošci pelagične lignje, s izuzetkom nekto-bentoskog sepiolida S. leucoptera. Čini se da nijedna vrsta od navedenih tamo nije uspostavila stabilnu populaciju, osim potonje navednih vrsta. Naprotiv, glavonošci koji ulaze u Sredozemno more iz Crvenog mora kroz Sueski kanal (lesepsijski migranti) vode bentoski način života. Ipak, dvije vrste S. lessoniana i Amphioctopus sp., uspostavile su stabilne populacije u istoč-nom dijelu.
Konačno, pojave pelagične hobotnice T. gracilis pripisuju se, u literaturi, prijenosu posredovanim antropogenim utjecajem.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Understanding the role of dispersal and adaptation in the evolutionary history of marine species is essential for predicting their response to changing conditions. We analyzed patterns of genetic ...differentiation in the key tropical calcifying species of large benthic foraminifera Amphistegina lobifera to reveal the evolutionary processes responsible for its biogeographic distribution. We collected specimens from 16 sites encompassing the entire range of the species and analyzed hypervariable fragments of the 18S SSU rDNA marker. We identified six hierarchically organized genotypes with mutually exclusive distribution organized along a longitudinal gradient. The distribution is consistent with diversification occurring in the Indo‐West Pacific (IWP) followed by dispersal toward the periphery. This pattern can be explained by: (a) high dispersal capacity of the species, (b) habitat heterogeneity driving more recent differentiation in the IWP, and (c) ecological‐scale processes such as niche incumbency reinforcing patterns of genotype mutual exclusion. The dispersal potential of this species drives the ongoing range expansion into the Mediterranean Sea, indicating that A. lobifera is able to expand its distribution by tracking increases in temperature. The genetic structure reveals recent diversification and high rate of extinction in the evolutionary history of the clade suggesting a high turnover rate of the diversity at the cryptic level. This diversification dynamic combined with high dispersal potential, allowed the species to maintain a widespread distribution over periods of geological and climatic upheaval. These characteristics are likely to allow the species to modify its geographic range in response to ongoing global warming without requiring genetic differentiation.
Genetic differentiation and distribution of populations can provide clues about processes shaping species evolutionary histories. We examined the genetic signature of globally distributed species of large benthic foraminifera in order to identify mechanisms acting at geological and ecological time scales. We found that while dispersal capacity allows populations to extend their range, geographic distribution was strongly shaped by biogeographic breaks and niche incumbency.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Phytomyxids (Phytomyxea) are obligate endosymbionts of many organisms such as algae, diatoms, oomycetes and higher plants including seagrasses. Despite their supposed significant roles in the marine ...ecosystem, our knowledge of their marine diversity and distribution as well as their life cycles is very limited. Here we describe anatomy and morphology of several developmental stages of a phytomyxid symbiosis recently discovered on the petioles of the alien seagrass Halophila stipulacea (Forssk.) Asch. at a locality in the southeast Aegean Sea. Its earliest whitish stages appeared already on the youngest leaves at the apex of the newly formed rhizomes. The infected host cells grew in volume being filled with plasmodia which resulted in the formation of characteristic macroscopic galls. The plasmodia eventually cleaved into spores and in the final stage recorded by us, the dark brown to black galls contained mature resting spores often occurring in duplexes and possessing thick verrucous outer walls. Based on its anatomo-morphological features the phytomyxid was assigned as Plasmodiophora cf. halophilae. Little is so far known about the origins and eco-physiological functioning of this rare symbiosis. However, seemingly similar infection patterns were reported in 1913 on Halophila ovalis (R. Br.) Hook. f. from Java and in 1995 on H. stipulacea from Sicily. Since H. stipulacea is of the Indo-Pacific origin and no phytomyxid infection was observed on the co-occurring autochthonous seagrass Cymodocea nodosa, we hypothesize that its phytomyxid might have co-migrated into the Mediterranean through the Suez Canal, potentially reaching as far as the southern Ionian Sea.
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