Spread of the non-indigenous ascidian Aplidium accarense (Millar, 1953) in the Eastern Mediterranean Sea: morphological and molecular tools for an accurate identification

The aplousobranch ascidian Aplidium accarense (Millar, 1953) was first described on the western coast of Africa, where it is considered native. Afterwards, this species was introduced along south-American Atlantic coasts, where it affected local shellfish farms through a massive colonization of both natural and artificial substrata. Aplidium accarense has been recently reported along Catalan coasts and in the Tyrrhenian Seas (Western Mediterranean) where it represents a non-indigenous species, only recorded in harbours and aquaculture farms thus far. These Mediterranean records support the hypothesis that A. accarense is currently expanding within the basin, representing a potential invasive species. In this study, several colonies of A. accarense were found for the first time on artificial substrata within the semi-enclosed basin of the Mar Piccolo of Taranto (Italy, Ionian Sea), in the Eastern Mediterranean. Here we provide an updated description of A. accarense combining both morphological and molecular approaches, in order to allow an accurate and reliable identification of this expanding species. Comparing the morphology of the specimens collected from Taranto with the previous descriptions, a slight intra-specific variability has been noticed. Therefore, we provide detailed comparisons of the specimens found in Taranto with all the other A. accarense sampled in other areas of the world, in order to highlight the intra-species variability. The correct identification of a potentially-dangerous species such as A. accarense, represents a needed step for environmental monitoring purposes and for implementing management strategies to mitigate the effects of non-indigenous species on natural ecosystems and human activities

Polyclinum constellatum (Tunicata, Ascidiacea), an emerging non-indigenous species of the Mediterranean Sea: integrated taxonomy and the importance of reliable DNA barcode data

Polyclinum constellatum is a colonial ascidian with a pantropical distribution, recently introduced into the Eastern Mediter-ranean Sea, indeed it was reported along Egyptian and Turkish coasts in 2016 and 2018, respectively. In the present study we report its presence along the coasts of Greece and Italy (Eastern and Central Mediterranean Sea, respectively), using an integrated approach combining morphological and molecular analysis. Colonies of P. constellatum were collected from artificial substrata in the harbour of Taranto (Ionian Sea) in November 2018 and in the marina of Heraklion (Crete, Aegean Sea) in October 2019. Remarkably, several colonies observed and collected in the Heraklion marina appeared as two or more masses joined at their base or fused together, often with different colour morpho-types. Here we provide their detailed morphological description and molecular characterization using a long fragment of the mitochondrial COI sequence as a DNA barcode. Furthermore, we present and discuss a comparative table of the main morphological features of all species of the genus Polyclinum known to date and an accurate analysis of the reliability of the Polyclinum COI sequence currently available. Our study proves that P. constellatum is further spreading in the Eastern Mediterranean Sea and has already reached the Central Mediterranean Sea. Moreover, the pres-ent study reveals the presence of erroneously assigned Polyclinum COI sequences in public databases and a possible synonymy between the species P. constellatum, Polyclinum indicum Sebastian, 1954 (accepted as Polyclinum sebastiani Brunetti, 2007) and Polyclinum madrasensis Sebastian, 1952. Overall, our data provide a useful tool for the accurate and reliable identification of this expanding species in other non-investigated areas and suggest the most likely vector of introduction of this non-indigenous species in the investigated localities

Hitch-hikers of the sea: concurrent morphological and molecular identification of Symplegma brakenhielmi (Tunicata: Ascidiacea) in the western Mediterranean Sea

We report here one of the first records of the non-indigenous colonial ascidian Symplegma brakenhielmi (Michaelsen, 1904) in the western Mediterranean Sea. Colonies of this invasive species have been collected in 2014 and 2018 along North-eastern Sardinia coasts (Olbia, Italy). Further colonies have been observed in 2016 in the Mar Piccolo basin (Gulf of Taranto, Italy). Both areas are strongly influenced by anthropogenic activities such as commercial shipping and aquaculture, suggesting these human-mediated pathways the most likely vectors of introduction. In both areas, the colonies present two different color phenotypes, the yellow and the red type, with the yellow coloration never found before in the Mediterranean Sea. Morphological and DNA barcode analyses of the collected specimens show that both these color types belong to the same species. Phylogenetic and species delimitation analyses based on the DNA barcode confirm our identification as S. brakenhielmi, but also indicate a surprisingly high similarity with published sequences of other two species, including the co-generic species Symplegma rubra Monniot, 1972. Morphological and molecular examination of a large number of samples of these species would be need in the near future to clarify this issue

The Status of \u3ci\u3ePosidonia oceanica\u3c/i\u3e at Tremiti Islands Marine Protected Area (Adriatic Sea)

Simple Summary: The seagrass Posidonia oceanica is the most important marine phanerogam of the Mediterranean Sea due to its meadows’ complexity, persistence, and extension. These habitats provide a suite of ecosystem goods and services, being of primary importance in marine conservation. Despite their central role in the coastal ecology, P. oceanica meadows are undergoing overall deterioration and fragmentation in the basin mostly due to anthropogenic impacts at local to global scales. In the last decades, several management measures have been proposed aiming to improve the meadow health conditions, while the periodic monitoring of P. oceanica meadows allows for verifying their effectiveness. Here, we report the results of the monitoring of P. oceanica at Tremiti Islands Marine Protected Area (Adriatic Sea, Italy) carried out in 2003, 2015, and 2020. A general worsening was observed, particularly enhanced by direct anthropogenic impacts mostly related to anchoring practices, as well as by a certain level of sedimentation possibly deriving from coastal development. However, the identification of these impacts and the correct management of human activities to mitigate them produced positive results in a relatively short time span. Abstract: Posidonia oceanica meadows are Mediterranean coastal habitats of great conservation importance. This study is focused on a meadow located at Tremiti Islands Marine Protected Area (Adriatic Sea, Italy), which was monitored in 2003, 2015, and 2020 to evaluate its health state over time in relation to coastal human activities, which have been highly affecting this MPA for the last 20 years. To assess any change in the physiognomy of the meadow, rhizome density, percentage coverage, and lower limit progressions and/or regression over time were evaluated by scuba diving, while the distribution and extension of the meadow were assessed through habitat mapping using a side-scan sonar. Moreover, phenological and lepidochronological analyses were performed on the collected rhizomes to assess the leaf area index (LAI, m2m2) and the rhizome age (lepidochronological years). Our study showed a general deterioration of P. oceanica meadow from 2003 to 2020, with a significant reduction of its absolute and relative rhizome density and LAI at almost all sampling stations, absence of renovation of the meadow, and lower limit regression and overall worsening of the main conservation status indicators. However, appropriate management actions, such as the establishment of mooring buoy fields, supported the improvement of the P. oceanica status at the local scale with a significant increase in density and LAI and the presence of active stolonization processes, suggesting that mitigation actions can play a crucial role in the conservation of this habitat. On the contrary, local anthropogenic impacts, especially anchoring and coastal development, markedly affect the resilience of P. oceanica meadows to global stressors, such as climate change

An elongated COI fragment to discriminate botryllid species and as an improved ascidian DNA barcode

Botryllids are colonial ascidians widely studied for their potential invasiveness and as model organisms, however the morphological description and discrimination of these species is very problematic, leading to frequent specimen misidentifications. To facilitate species discrimination and detection of cryptic/new species, we developed new barcoding primers for the amplification of a COI fragment of about 860 bp (860-COI), which is an extension of the common Folmer's barcode region. Our 860-COI was successfully amplified in 177 worldwide-sampled botryllid colonies. Combined with morphological analyses, 860-COI allowed not only discriminating known species, but also identifying undescribed and cryptic species, resurrecting old species currently in synonymy, and proposing the assignment of clade D of the model organism Botryllus schlosseri to Botryllus renierii. Importantly, within clade A of B. schlosseri, 860-COI recognized at least two candidate species against only one recognized by the Folmer's fragment, underlining the need of further genetic investigations on this clade. This result also suggests that the 860-COI could have a greater ability to diagnose cryptic/new species than the Folmer's fragment at very short evolutionary distances, such as those observed within clade A. Finally, our new primers simplify the amplification of 860-COI even in non-botryllid ascidians, suggesting their wider usefulness in ascidians

Common polymorphisms in nitric oxide synthase (NOS) genes influence quality of aging and longevity in humans

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LC-HRMS-Database Screening Metrics for Rapid Prioritization of Samples to Accelerate the Discovery of Structurally New Natural Products

In order to accelerate the isolation and characterization of structurally new or novel secondary metabolites, it is crucial to develop efficient strategies that prioritize samples with greatest promise early in the workflow so that resources can be utilized in a more efficient and cost-effective manner. We have developed a metrics-based prioritization approach using exact LC-HRMS, which uses data for 24 618 marine natural products held in the PharmaSea database. Each sample was evaluated and allocated a metric score by a software algorithm based on the ratio of new masses over the total (sample novelty), ratio of known masses over the total (chemical novelty), number of peaks above a defined peak area threshold (sample complexity), and peak area (sample diversity). Samples were then ranked and prioritized based on these metric scores. To validate the approach, eight marine sponges and six tunicate samples collected from the Fiji Islands were analyzed, metric scores calculated, and samples targeted for isolation and characterization of new compounds. Structures of new compounds were elucidated by spectroscopic techniques, including 1D and 2D NMR, MS, and MS/MS. Structures were confirmed by computer-assisted structure elucidation methods (CASE) using the ACD/Structure Elucidator Suite

New Alien Mediterranean Biodiversity Records (October 2020)

This article includes 23 new records of alien and cryptogenic species in the Mediterranean Sea, belonging to 4 Phyla (Chordata, Echinodermata, Arthropoda and Mollusca), distributed from the Alboran to the Levantine Sea. Records are reported from eight countries listed from West to East as follows: Algeria: new records of the Atlantic blue crab Callinectes sapidus; Spain: further spread and establishment of the sea slug Lamprohaminoea ovalis in continental shores; Tunisia: first record of the Atlantic Blue Crab Callinectes sapidus in the Gulf of Gabes; Italy: a new occurrence of the pufferfish Lagocephalus sceleratus in Northern Ionian waters; first record of Cephalopholis taeniops in the Ionian Sea; first record of the redlip blenny, Ophioblennius atlanticus in the Ionian Sea; Slovenia: first record of the isopod Paranthura japonica in Slovenia; Greece: first record of the molluscs Eunaticina papilla, Plocamopherus ocellatus and the fish Cheilodipterus novemstriatus; first record of the ascidian Ecteinascidia turbinata in Kriti; the long-spined sea urchin Diadema setosum in the Ionian Sea; Turkey: first record of the sea spider Ammothea hilgendorfi; the stomatopod Cloridina cf. ichneumon; the fishes Pempheris rhomboidea from the Sea of Marmara and Paranthias furcifer from the Aegean Sea; Lebanon: new records of the fishes Arothron hispidus, Rachycentron canadum, Heniochus intermedius and Acanthurus monroviae; first record of Acanthostracion polygonius. The records of Cloridina cf. ichneumon from southern Turkey and the fish Acanthostracion polygonius from Lebanon, both being the first Mediterranean records, are noteworthy

“New Alien Mediterranean Biodiversity Records” (March 2021)

This article includes twenty (20) new records of alien and cryptogenic species in the Mediterranean Sea, belonging to six (6) Phyla (Rhodophyta, Tracheophyta, Mollusca, Arthropoda, Bryozoa, and Chordata) distributed from the Eastern Mediterranean to the Sea of Alboran. The records are reported from nine (9) countries and can be classified into two categories: new records for the Mediterranean Sea and new records of non-indigenous species expanding within the Mediterranean Sea. The first category includes the gastropod Turbo radiatus from Lebanon coasts, the portunid crab Charybdis (Charybdis) natator from Tunis southern lagoon, the mollusc Thuridilla mazda from South Spain, and the nudibranch Okenia picoensis from the Alboran coasts of Spain and from Malta. The second category includes the bivalve Nudiscintilla cf. glabra from the Aegean coast of Turkey, the rhodophyte Colaconema codicola from the North Aegean coasts of Greece, the naked band gaper Champsodon nudivittis from the Sea of Marmara, Turkey. Also, the brachyuran Gonioinfradens giardi from the Greek Ionian waters, the codlet Bregmaceros nectabanus from the Croatian coasts of the Adriatic Sea, and the bryozoan Arbopercula tenella and copepod Parvocalanus crassirostris both from the Gulf of Trieste, Slovenian and Italian coasts, respectively. New records were also reported for the ascidian Distaplia bermudensis from brackish the Gulf of Naples, Italy, the damselfish Abudefduf cf. saxatilis and the seagrass Halophila stipulacea from Sardinia, Tyrrhenian Sea, and for the fish Paranthias furcifer from the harbour of Almeria, Alboran Sea, Spain. Through these records, an understanding of the expanding mechanisms and processes and, if possible, the development of mitigation measures within the region will be further facilitated

New Alien Mediterranean Biodiversity Records (August 2022)

In this Collective Article on alien and cryptogenic diversity in the Mediterranean Sea we report a total of 19 species belonging to nine Phyla and coming from nine countries. Several of these records concern fish species, and of particular interest are the first records of: Terapon puta for Italian waters; Pteragopus trispilus from Malta; Plotosus lineatus from Cyprus; and the northernmost Mediterranean record of Lagocephalus sceleratus. The northernmost Mediterranean record was also reported for the sea urchin Diadema setosum. The portunid crab Thalamita poissonii was recorded for the first time in Libya. The copepod Pseudodiaptomus marinus was recorded for the first time in the Marmara Sea. The polychaete Branchiomma luctuosum was recorded for the first time from the Mediterranean coast of France. The alien anemone Diadumene lineata was recorded for the first time from Slovenia. The macroalgae Sargassum furcatum was recorded for the first time from Italy. The new Mediterranean records here reported help tracing abundance and distribution of alien and cryptic species in the Mediterranean Sea