Analisi morfologica e genetica di Syllis gracilis (Polychaeta, Syllidae) in ambienti marini e salmastri.

Recenti ricerche hanno messo in evidenza in numerosi gruppi di invertebrati marini la presenza, all’interno di quelle classicamente definite su base morfologica come singole specie, di diverse specie criptiche. Tale diversificazione è talvolta legata ad ambienti le cui caratteristiche fisiche determinano forti spinte selettive sugli organismi che li popolano, quali ad esempio gli ambienti salmastri, in altri casi è semplicemente determinata dalla distanza geografica o dalla presenza di barriere alla dispersione. Syllis gracilis Grube, 1840, è un polichete che vive nelle concrezioni biogene dei fondi duri superficiali in ambienti costieri marini e salmastri di tutto il Mar Mediterraneo. Allo scopo di approfondire le conoscenze su questa specie a larga ripartizione ecologica e geografica, nel corso di due anni sono stati effettuati numerosi campionamenti in diverse località lungo le coste italiane; la specie in questione, infatti, non è di semplice reperimento, in quanto presenta una distribuzione non uniforme molto probabilmente legata a piccole variazioni di parametri ambientali, ed è stato possibile raccoglierla solo in 13 località situate nel Mar Ligure, nel Mar Tirreno, nel Mar di Sardegna e nel Mar Adriatico. Quattro delle 13 popolazioni raccolte provengono da ambienti di transizione (ambienti salmastri e porti), le altre nove da ambienti marini costieri. In otto località (due salmastre e sei marine) è stato possibile raccogliere un numero rappresentativo di esemplari (N>10). Si prevede di caratterizzare gli individui di Syllis gracilis campionati sia morfologicamente, attraverso caratteri semi-quantitativi di univoco rilevamento anche sugli esemplari fissati, sia geneticamente, utilizzando marcatori mitocondriali. Attraverso l’approccio morfologico e genetico si intende testare l’ipotesi di una separazione a livello specifico tra diverse popolazioni e in particolare tra quelle di ambiente marino e di ambiente salmastro, già emersa in precedenti studi

Važnost podvodne fotografije u određivanju kripto-bentičkih vrsta: novi in situ zapisi nekih glavoča (Teleostei: Gobiidae) iz talijanskih voda, s ekološkim bilješkama

Although recent scuba-diving techniques improved biological research and exploration in shallow waters, distribution and ecology of cryptobenthic gobies (Teleostei: Gobiidae) are still widely unknown. In this work new records of 5 species, including some ecological information collected by scuba divers and underwater photographers, are presented for Italy (Mediterranean Sea).Iako su nedavno tehnike ronjenja poboljšale biološka istraživanja u plitkim vodama, distribucija i ekologija kripto-bentičkih glavoča (Teleostei: Gobiidae) je i dalje potpuna nepoznanica. U ovom istraživanju imamo nove zapise 5 vrsta, uključujući neke ekološke informacije koje su sakupili ronioci i podvodni fotografi, za područje Italije (Sredozemno more)

Društvene mreže omogućuju rano otkrivanje nezavičajnih vrsta: prvi nalaz crvene hame Sciaenops ocellatus (Actinopterygii: Perciformes: Sciaenidae) u talijanskim vodama

The red drum Sciaenops ocellatus is a large demersal fish that represents one of the top predators in estuarine environments of its native range. This species is commonly reared in aquaculture facilities, and it has already been reported as non indigenous from several countries. Here we report its first sighting in Italian waters, as well as the second documented occurrence for the Mediterranean Sea. The individual was landed in southern Sicily by artisanal fishery and this unusual observation was immediately shared on Facebook. The importance of considering social networks as tools for NIS detection is briefly discussed in light of the recognized difficulties to properly track biological introductions in the marine environment.Crvena hama, Sciaenops ocellatus, je velika demersalna riba, koja je jedna od najvećih grabežljivaca u estuarijskim okruženjima njezinog prirodnog areala rasprostranjenja. Ova vrsta se obično uzgaja u akvakulturi, a već je zabilježena kao nezavičajna u nekoliko zemalja. U ovom radu utvrđeno je prvo viđenje ove vrste u talijanskim vodama, koje je ujedno druga dokumentirana pojava u Sredozemnom moru. Primjerak je ulovljen tijekom priobalnog ribolova u južnoj Siciliji. Ova neuobičajena pojava je odmah podijeljena na društvenoj mreži (Facebook). Važnost razmatranja društvenih mreža kao alata za otkrivanje nezavičajnih vrsta kratko je raspravljan u svjetlu prepoznatih poteškoća kako bi se pravilno pratili biološki unosi u morski okoliš

Phylogeography of Aphanius fasciatus (Osteichthyes: Aphaniidae) in the Mediterranean Sea, with a focus on its conservation in Cyprus

AbstractAphanius fasciatus is a small fish occurring in Mediterranean brackish environments. In Cyprus it is known from three localities separated by long stretches of coast. The genetic diversity of these populations was evaluated using fragments of two mitochondrial genes. A comparison with the other available data showed that Cyprus populations represent a distinct lineage. The other lineages are concentrated in a relatively small area between the Strait of Sicily and the Western Ionian Sea, while all other areas include a subset of these lineages, suggesting that the aforementioned area might have acted as a glacial refugium. Landlocked North-African populations diverge from all other populations, suggesting that they might have originated in the Late Pleistocene, during transgression events of the Mediterranean Sea in North-African inland water bodies. The genetic diversity of A. fasciatus varied across different Cyprus populations, with a pattern mirroring the degree of environmental degradation, which likely affected population genetic variability through demographic reductions. The three Cyprus populations showed genetic uniqueness, suggesting the need of population-based management practices; the low genetic diversity of two populations, and the number of threats affecting them, suggest that the species should be considered endangered at national level and deserves protection measures

Non-indigenous polychaetes along the coasts of Italy: a critical review

Non-indigenous species (NIS) represent one of the most relevant threats to biodiversity, ecosystem functioning and human activities, and their occurrence and spread have been the subject of numerous works and revisions. However, the information available is rather confused for several taxa, including polychaetes, which are characterised by having a high number of cryptogenic and questionable species. This work aims at providing a revised checklist of alien polychaetes occurring along the coasts of Italy, based on the examination of newly collected and deposited material and on the critical analysis of published and gray literature, and whenever possible on the re-examination of historical material. Of the 86 polychaete species reported as NIS in Italian waters, 25 are confirmed as alien species, while 3 are cryptogenic, and 40 should be considered questionable. Finally, 18 species were excluded from non-indigenous species checklists, either because they are native, or because they represent misidentifications of other species. The high number of cryptogenic and questionable species points at the need of molecular studies and taxonomic revisions for the majority of polychaete taxa reported as NIS, in order to clarify their taxonomy, origin, introduction pathways and spreading patterns

Environmental features drive lineage diversification in the Aricidea assimilis species complex (Annelida, Paraonidae) in the Mediterranean Sea

Individuals identified as Aricidea assimilis Tebble, 1959 were collected from ten localities across the Mediterranean Sea from 0.5 to 225 m depth in order to have a wide coverage of the species habitats and geographic range and to assess the effects of environmental factors and biogeographical barriers on molecular and morphological diversity. Two mitochondrial and one nuclear markers were used to reconstruct phylogenetic relationships and test the occurrence of cryptic species. We observed two highly divergent lineages, one including all individuals from shallow, sandy environments (<10 m depth) and the other with the individuals from deeper muddy bottoms (30-225 m depth). Less pronounced divergence was detected between morphologically distinct brackish-water individuals and the remaining shallow-water individuals. The divergence observed between deep-water and shallow-water lineages is consistent with the hypothesis of distinct species. The ambiguous results of species delimitation tests applied to the two shallow-water sub-lineages might instead suggest a process of incipient speciation, even if this hypothesis needs additional evidence. These results suggest that sediment represents the main factor driving genetic divergence and ultimately cryptic speciation in A. assimilis, while other depth-associated factors and geographical barriers do not seem to significantly contribute to the genetic architecture of this species, suggesting the occurrence of wide-range larval dispersal

A complex species complex: The controversial role of ecology and biogeography in the evolutionary history of Syllis gracilis Grube, 1840 (Annelida, Syllidae)

The cryptic diversity in the polychaete Syllis gracilis Grube, 1840, in the Mediterranean Sea was examined with an integrative morpho-molecular approach. Individuals of S. gracilis were collected at eleven Mediterranean localities to provide an insight into the role of brackish environments in inducing cryptic speciation. The examination of morphological features combined with a molecular genetic analysis based on a partial sequence of the 16S rRNA gene highlighted discrepancies between morphological and molecular diversity. Morphological data allowed to identify a morphotype with short appendages occurring in coralline algae communities and another one with long appendages observed in brackish-water environments and Sabellaria reefs. Multivariate analyses showed that sampling localities were the greatest source of morphological divergence, suggesting that phenotypic plasticity may play a role in local adaptations of S. gracilis populations. Molecular data showed the occurrence of four divergent lineages not corresponding to morphological clusters. Different species delimitation tests gave conflicting results, retrieving, however, at least four separated entities. Some lineages occurred in sympatry and were equally distributed in marine and brackish-water environments, excluding a biogeographic or ecological explanation of the observed pattern and suggesting instead ancient separation between lineages and secondary contact. The co-occurrence of different lineages hindered the identification of the lineage corresponding to S. gracilis sensu stricto. The discrepancy between morphological and molecular diversity suggests that different environmental and biogeographic features may interact in a complex and unpredictable way in shaping diversity patterns. An integrative approach is needed to provide a satisfactory insight on evolutionary processes in marine invertebrates

. Ecological role and phylogenetic position of a new habitat-forming species (Canalipalpata, Sabellidae) from the Mediterranean mesophotic soft-bottoms

This study presents a description of Bispira riccardi sp. nov., a new habitat-forming sabellid polychaete from the mesophotic NW Mediterranean Sea. Individuals, up to 20 cm long, show a peculiar morphology of radioles, thoracic uncini, companion chaetae and ventral shield of the collar. The phylogenetic position of this new taxon in the genus Bispira has been validated using nuclear (18S rRNA) and mitochondrial (COI) markers. Aggregations of B. riccardi sp. nov. were found by ROV on horizontal muddy bottoms between 56 and 85 m, in areas subjected to high trophic inputs. Patches are fragmented and dense (up to 943 individuals m 2) probably accounting for various hectares. A 5-days continuous monitoring, carried out using an autonomous lander, revealed that the contraction of the branchial crown was positively affected by temperature and current, rapidly responding to meteorological events. The filtering activity and high density of these fields suggest a considerable impact on the pelagic-benthic coupling and the amount of organic matter in the sediments. Indeed, meiofaunal abundance and diversity within the aggregations resulted significantly higher than in outer stations. These findings highlight the undisclosed potential of the deep Mediterranean Sea for sabellid diversity and their importance as habitat-forming species on mesophotic soft bottoms

Revealing the diversity of the green Eulalia (Annelida, Phyllodocidae) species complex along the European coast, with description of three new species

The green phyllodocids Eulalia clavigera and E. viridis are a known European pseudo-cryptic complex, but questions about its distribution and evidence of additional lineages in previous studies call for an investigation of the real diversity within the complex. We analyze DNA sequences (mtCOI-5P, ITS, and 28S rRNA) of different populations of E. clavigera from intertidal and subtidal marine waters along the North East Atlantic, Mediterranean Sea, the Azores and Webbnesia (Madeira, Savage islands and Canaries), and populations of E. viridis from the Scandinavia. This provided compelling evidence for the existence of six additional divergent evolutionary lineages, three of the most abundant being described here as new species: Eulalia feliciae sp. nov., intertidal and unique to the Western Mediterranean, Eulalia madeirensis sp. nov., subtidal and unique to the Madeira Island (Portugal), and Eulalia xanthomucosa sp. nov., mostly subtidal and occurring in the British Isles and southern France. Complementary morphometric analyses showed that E. feliciae sp. nov. and E. madeirensis sp. nov. formed two independent morphometric clusters, while E. xanthomucosa sp. nov. often overlapped with E. clavigera sensu stricto (s. s.), although being unique in showing a yellow coloration and parapodial cirri on median segments larger in relation to its body size. Recent biotechnological findings based on “E. clavigera” specimens highlight the importance of formally describing cryptic complexes, since each lineage chemistry might be unique and may have a range of distinct effects and applications.This study was supported by the project ATLANTIDA–Platform for the monitoring of the North Atlantic Ocean and tools for the sustainable exploitation of the marine resources, with the reference NORTE-01–0145-FEDER-000040, co-financed by the European Regional Development Fund (ERDF), through Programa Operacional Regional do Norte (NORTE 2020). Thanks are due, for the financial support to CESAM (UIDB/50017/2020 + UIDP/50017/2020), to Portuguese Foundation for Science and Technology and Ministry of Education and Science (FCT/MEC) through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. Marcos A. L. Teixeira was supported by a PhD grant from FCT co-financed by ESF (SFRH/BD/131527/2017) and from the DNAqua-Net STSM grant “Rich and hidden biodiversity not yet barcoded in the Canary archipelago (Spain) as an opportunity to enrich the DNA barcode reference library for European polychaetes,” under the EU Cost action CA15219–Developing new genetic tools for bio-assessment of aquatic ecosystems in Europe. Pedro E. Vieira was supported by national funds through the Portuguese Foundation for Science and Technology (FCT, I.P.) in the scope of the project (early detection and monitoring of non-indigenous species in coastal ecosystems based on high-throughput sequencing tools, PTDC/BIA-BMA/29754/2017). Ascensão Ravara was supported by national funds, through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Arne Nygren was supported by the Norwegian Taxonomy Initiative [https://www.biodiversity.no/Pages/135523] (Cryptic polychaete species in Norwegian waters, knr 49–13, pnr 70184228), the Swedish Taxonomy Initiative [https://www.artdatabanken.se/en/the-swedish-taxonomy-initiative/] (Polychaete species complexes in Swedish waters, dnr 140/07 1.4 and 166/08 1.4), and Kungliga Fysiografiska sällskapet Nilsson-Ehle donationerna [https://www.fysiografen.se/sv/]

Project “Biodiversity MARE Tricase”: A Species Inventory of the Coastal Area of Southeastern Salento (Ionian Sea, Italy)

Biodiversity is a broad concept that encompasses the diversity of nature, from the genetic to the habitat scale, and ensures the proper functioning of ecosystems. The Mediterranean Sea, one of the world’s most biodiverse marine basins, faces major threats, such as overexploitation of resources, pollution and climate change. Here we provide the first multi-taxa inventory of marine organisms and coastal terrestrial flora recorded in southeastern Salento (Ionian Sea, Italy), realized during the project “Biodiversity MARE Tricase”, which provided the first baseline of species living in the area. Sampling was carried out by SCUBA and free diving, fishing gears, and citizen science from 0 to 70 m. Overall, 697 taxa were found between March 2016 and October 2017, 94% of which were identified to the species level. Of these, 19 taxa represented new records for the Ionian Sea (36 additional new records had been reported in previous publications on specific groups, namely Porifera and Mollusca Heterobranchia), and two findings represented the easternmost records in the Mediterranean Sea (Helicosalpa virgula and Lampea pancerina). For eight other taxa, our findings represented the only locality in the Ionian Sea, besides the Straits of Messina. In addition to the species list, phenological events (e.g., blooms, presence of reproductive traits and behaviour) were also reported, with a focus on gelatinous plankton. Our results reveal that even for a relatively well-known area, current biodiversity knowledge may still be limited, and targeted investigations are needed to fill the gaps. Further research is needed to understand the distribution and temporal trends of Mediterranean biodiversity and to provide baseline data to identify ongoing and future changes