Multilocus phylogenetic analysis of the genus Atherina (Pisces: Atherinidae)

Sand-smelts are small fishes inhabiting inshore, brackish and freshwater environments and with a distribution in the eastern Atlantic and Mediterranean Sea, extending south into the Indian Ocean. Here, we present a broad phylogenetic analysis of the genus Atherina using three mitochondrial (control region, 12S and 16S) and two nuclear markers (rhodopsin and 2nd intron of S7). Phylogenetic analyses fully support the monophyly of the genus. Two anti-tropical clades were identified, separating the South African Atherina breviceps from the north-eastern Atlantic and Mediterranean Atherina’ species. In European waters, two groups were found. The first clade formed by a well supported species-pair: Atherina presbyter (eastern Atlantic) and Atherina hepsetus (Mediterranean), both living in marine waters; a second clade included Atherina boyeri (brackish and freshwater environments) and two independent lineages of marine punctated and non-punctated fishes, recently proposed as separate species. Sequence divergence values strongly suggest multiple species within the A. boyeri complex

Linking Water to the Bottom: eDNA Study of Benthic Invertebrates and Invasive Species in the Venice Lagoon

This study investigates the benthic invertebrate community in the Venice Lagoon using environmental DNA (eDNA) metabarcoding based on superficial water samples. Our objective is to understand if, in a shallow lagoon system, sampling at the surface can provide information on benthic biodiversity, allowing us to establish a baseline for future assessments and to monitor the community's seasonal and spatial variation. eDNA was collected from surface water samples at two sites during nine sampling campaigns from November 2018 to October 2019, and metabarcoding was performed using an available primer pair targeting 16S mitochondrial rDNA of echinoderms, never tested empirically before. Analyses revealed 80 taxonomic units, five not assigned at the species level, belonging not only to the phylum Echinodermata but predominantly assigned to Mollusca, with the majority of the identified species (60 out of 75) representing benthic invertebrates. Several species known to be invasive were detected, some previously recorded in the Venice Lagoon environment and others detected for the first time. Significant spatial differences in species composition were observed between the northern and the southern site of the lagoon. Temporal variation of the benthic community was also observed, mainly due to the distinctiveness of autumn samples, highlighting the dynamic nature of the Venice Lagoon ecosystem. Our results confirm the utility of eDNA for ongoing biodiversity monitoring and management and show that eDNA isolated from superficial water can provide information on the benthic invertebrate community, which might be particularly useful for biodiversity assessment in lagoons, ports, and areas characterized by limited or interdicted access

Deep transfer learning for star cluster classification: I. application to the PHANGS–HST survey

We present the results of a proof-of-concept experiment that demonstrates that deep learning can successfully be used for production-scale classification of compact star clusters detected in Hubble Space Telescope(HST) ultraviolet-optical imaging of nearby spiral galaxies (⁠D≲20Mpc⁠) in the Physics at High Angular Resolution in Nearby GalaxieS (PHANGS)–HST survey. Given the relatively small nature of existing, human-labelled star cluster samples, we transfer the knowledge of state-of-the-art neural network models for real-object recognition to classify star clusters candidates into four morphological classes. We perform a series of experiments to determine the dependence of classification performance on neural network architecture (ResNet18 and VGG19-BN), training data sets curated by either a single expert or three astronomers, and the size of the images used for training. We find that the overall classification accuracies are not significantly affected by these choices. The networks are used to classify star cluster candidates in the PHANGS–HST galaxy NGC 1559, which was not included in the training samples. The resulting prediction accuracies are 70 per cent, 40 per cent, 40–50 per cent, and 50–70 per cent for class 1, 2, 3 star clusters, and class 4 non-clusters, respectively. This performance is competitive with consistency achieved in previously published human and automated quantitative classification of star cluster candidate samples (70–80 per cent, 40–50 per cent, 40–50 per cent, and 60–70 per cent). The methods introduced herein lay the foundations to automate classification for star clusters at scale, and exhibit the need to prepare a standardized data set of human-labelled star cluster classifications, agreed upon by a full range of experts in the field, to further improve the performance of the networks introduced in this study

A population genomics insight by 2b‐RAD reveals populations' uniqueness along the Italian coastline in Leptopsammia pruvoti (Scleractinia, Dendrophylliidae)

Aim Marine bioconstructions such as coralligenous formations are hotspot of biodiversity and play a relevant ecological role in the preservation of biodiversity by providing carbon regulation, protection and nursery areas for several marine species. For this reason, the European Union Habitat Directive included them among priority habitats to be preserved. Although their ecological role is well established, connectivity patterns are still poorly investigated, representing a limit in conservation planning. The present study pioneers a novel approach for the analysis of connectivity in marine bioconstructor species, which often lack suitable genetic markers, by taking advantage of next‐generation sequencing techniques. We assess the geographical patterns of genomic variation of the sunset cup coral Leptopsammia pruvoti Lacaze‐Duthiers, 1897, an ahermatypic, non‐zooxanthellate and solitary scleractinian coral species common in coralligenous habitats and distributed across the Mediterranean Sea. Location The Italian coastline (Western and Central Mediterranean). Methods We applied the restriction site‐associated 2b‐RAD approach to genotype over 1,000 high‐quality and filtered single nucleotide polymorphisms in 10 population samples. Results The results revealed the existence of a strongly supported genetic structure, with highly significant pairwise FST values between all the population samples, including those collected about 5 km apart from each other. Moreover, genomic data indicate that the strongest barriers to gene flow are between the western (Ligurian–Tyrrhenian Sea) and the eastern side (Adriatic Sea) of the Italian peninsula. Main conclusions The strong differentiation found in L. pruvoti is similar to that found in other species of marine bioconstructors investigated in this area, but it strongly contrasts with the small differences found in many fish and invertebrates at the same geographical scale. All in one, our results highlight the importance of assessing connectivity in species belonging to coralligenous habitats as, due to their limited dispersal ability, they might require specific spatial conservation measures

Managing Polyploidy in Ex Situ Conservation Genetics: The Case of the Critically Endangered Adriatic Sturgeon (Acipenser naccarii)

While the current expansion of conservation genetics enables to address more efficiently the management of threatened species, alternative methods for genetic relatedness data analysis in polyploid species are necessary. Within this framework, we present a standardized and simple protocol specifically designed for polyploid species that can facilitate management of genetic diversity, as exemplified by the ex situ conservation program for the tetraploid Adriatic sturgeon Acipenser naccarii. A critically endangered endemic species of the Adriatic Sea tributaries, its persistence is strictly linked to the ex situ conservation of a single captive broodstock currently decimated to about 25 individuals, which represents the last remaining population of Adriatic sturgeon of certain wild origin. The genetic variability of three F1 broodstocks available as future breeders was estimated based on mitochondrial and microsatellite information and compared with the variability of the parental generation. Genetic data showed that the F1 stocks have only retained part of the genetic variation present in the original stock due to the few parent pairs used as founders. This prompts for the urgent improvement of the current F1 stocks by incorporating new founders that better represent the genetic diversity available. Following parental allocation based on band sharing values, we set up a user-friendly tool for selection of candidate breeders according to relatedness between all possible parent-pairs that secures the use of non-related individuals. The approach developed here could also be applied to other endangered tetraploid sturgeon species overexploited for caviar production, particularly in regions lacking proper infrastructure and/or expertise

One-quarter of freshwater fauna threatened with extinction

Freshwater ecosystems are highly biodiverse1 and important for livelihoods and economic development2, but are under substantial stress3. To date, comprehensive global assessments of extinction risk have not included any speciose groups primarily living in freshwaters. Consequently, data from predominantly terrestrial tetrapods4,5 are used to guide environmental policy6 and conservation prioritization7, whereas recent proposals for target setting in freshwaters use abiotic factors8–13. However, there is evidence14–17 that such data are insufficient to represent the needs of freshwater species and achieve biodiversity goals18,19. Here we present the results of a multi-taxon global freshwater fauna assessment for The IUCN Red List of Threatened Species covering 23,496 decapod crustaceans, fishes and odonates, finding that one-quarter are threatened with extinction. Prevalent threats include pollution, dams and water extraction, agriculture and invasive species, with overharvesting also driving extinctions. We also examined the degree of surrogacy of both threatened tetrapods and freshwater abiotic factors (water stress and nitrogen) for threatened freshwater species. Threatened tetrapods are good surrogates when prioritizing sites to maximize rarity-weighted richness, but poorer when prioritizing based on the most range-restricted species. However, they are much better surrogates than abiotic factors, which perform worse than random. Thus, although global priority regions identified for tetrapod conservation are broadly reflective of those for freshwater faunas, given differences in key threats and habitats, meeting the needs of tetrapods cannot be assumed sufficient to conserve freshwater species at local scales.publishedVersio

Association between multimorbidity and postoperative mortality in patients undergoing major surgery: a prospective study in 29 countries across Europe

BackgroundMultimorbidity poses a global challenge to healthcare delivery. This study aimed to describe the prevalence of multimorbidity, common disease combinations and outcomes in a contemporary cohort of patients undergoing major abdominal surgery.MethodsThis was a pre-planned analysis of a prospective, multicentre, international study investigating cardiovascular complications after major abdominal surgery conducted in 446 hospitals in 29 countries across Europe. The primary outcome was 30-day postoperative mortality. The secondary outcome measure was the incidence of complications within 30 days of surgery.ResultsOf 24,227 patients, 7006 (28.9%) had one long-term condition and 10,486 (43.9%) had multimorbidity (two or more long-term health conditions). The most common conditions were primary cancer (39.6%); hypertension (37.9%); chronic kidney disease (17.4%); and diabetes (15.4%). Patients with multimorbidity had a higher incidence of frailty compared with patients <= 1 long-term health condition. Mortality was higher in patients with one long-term health condition (adjusted odds ratio 1.93 (95%CI 1.16-3.23)) and multimorbidity (adjusted odds ratio 2.22 (95%CI 1.35-3.64)). Frailty and ASA physical status 3-5 mediated an estimated 31.7% of the 30-day mortality in patients with one long-term health condition (adjusted odds ratio 1.30 (95%CI 1.12-1.51)) and an estimated 36.9% of the 30-day mortality in patients with multimorbidity (adjusted odds ratio 1.61 (95%CI 1.36-1.91)). There was no improvement in 30-day mortality in patients with multimorbidity who received pre-operative medical assessment.ConclusionsMultimorbidity is common and outcomes are poor among surgical patients across Europe. Addressing multimorbidity in elective and emergency patients requires innovative strategies to account for frailty and disease control. The development of such strategies, that integrate care targeting whole surgical pathways to strengthen current systems, is urgently needed for multimorbid patients. Interventional trials are warranted to determine the effectiveness of targeted management for surgical patients with multimorbidity

One-quarter of freshwater fauna threatened with extinction

Freshwater ecosystems are highly biodiverse and important for livelihoods and economic development , but are under substantial stress . To date, comprehensive global assessments of extinction risk have not included any speciose groups primarily living in freshwaters. Consequently, data from predominantly terrestrial tetrapods are used to guide environmental policy and conservation prioritization , whereas recent proposals for target setting in freshwaters use abiotic factors . However, there is evidence that such data are insufficient to represent the needs of freshwater species and achieve biodiversity goals . Here we present the results of a multi-taxon global freshwater fauna assessment for The IUCN Red List of Threatened Species covering 23,496 decapod crustaceans, fishes and odonates, finding that one-quarter are threatened with extinction. Prevalent threats include pollution, dams and water extraction, agriculture and invasive species, with overharvesting also driving extinctions. We also examined the degree of surrogacy of both threatened tetrapods and freshwater abiotic factors (water stress and nitrogen) for threatened freshwater species. Threatened tetrapods are good surrogates when prioritizing sites to maximize rarity-weighted richness, but poorer when prioritizing based on the most range-restricted species. However, they are much better surrogates than abiotic factors, which perform worse than random. Thus, although global priority regions identified for tetrapod conservation are broadly reflective of those for freshwater faunas, given differences in key threats and habitats, meeting the needs of tetrapods cannot be assumed sufficient to conserve freshwater species at local scales