We report the first record of the brine shrimp genus Artemia (Branchiopoda, Anostraca, Artemiidae) from Armenia, based on specimens collected in two saline ponds (collectively referred to as “Lake Aghi”) in the Yerevan area. Individuals were identified through an integrative approach combining morphological examination and mitochondrial cytochrome c oxidase subunit I (COI) sequencing. All examined specimens were females and exhibited morphological traits compatible with parthenogenetic Artemia, although these characters alone are not sufficient for a definitive identification. Molecular analyses revealed a single COI haplotype attributable to a parthenogenetic lineage widely distributed across the Palaearctic region and closely related to the sexual species A. amati. No evidence of the occurrence of the invasive species Artemia franciscana was found. A synopsis of the anostracan fauna of Armenia based on available literature is also provided. This finding broadens current knowledge of anostracan diversity and distribution in the South Caucasus region and highlights the need for further surveys to better characterize the large branchiopod fauna of the country.

In this study, we explored the population genetic structure and its relation to environmental adaptations of the dolphinfish (Coryphaena hippurus) in the western Atlantic Ocean and Mediterranean Sea. Although previously two populations within the Mediterranean Sea were identified, recent evidence suggests more complex structuring. We employed 3RAD sequencing on 138 samples from the Atlantic and Mediterranean, obtaining a total of 20,072 SNPs of which 24 SNPs were strongly associated with temperature and salinity variables (putative adaptive outlier loci). Results revealed a clear genetic differentiation between the Atlantic and Mediterranean basins, with practically no connectivity between them, confirming the Mediterranean basin's long-term isolation. Within the Mediterranean basin, subtle genetic differences were detected between eastern and western Mediterranean sub-basins based on neutral loci with an increased signal of differences in the outlier loci associated with temperature and salinity that identified further differences into three genetically distinct groups, despite an overall high genetic connectivity. Environmental-genetic association analyses identified salinity, temperature and nitrate as major drivers of genetic variation. The most informative dataset (outlier SNPs related to temperature and salinity) explained over 80% of the genetic variation through a model incorporating multiple oceanographic variables. Overall, this research underscores how high-resolution genomic tools can detect hidden genetic structure and adaptation, even in highly dispersive marine species. These findings are essential for fisheries management, particularly in the Mediterranean Sea, where distinct local adaptations may be at risk from global environmental change. Recognizing and preserving this genetic diversity is crucial for the long-term sustainability of dolphinfish populations under climate and anthropogenic pressures.

Gastrotrichs (Phylum Gastrotricha) are widespread and species-rich components of benthic and periphytic communities, where they are thought to contribute substantially to food-web functioning by linking the microbial loop to higher trophic levels through their feeding on detritus, bacteria, microalgae, and fungi, and serve as prey for larger animals. Despite the well-recognized role as primary consumers, their position as potential prey remains largely unresolved, with documented predators so far restricted to carnivorous protists. Here, we report the first documented case of metazoan predation on a freshwater gastrotrich, in which a cyclopoid copepod actively captures and partially consumes a chaetonotid species. The interaction was first detected under minimally disturbed conditions and subsequently replicated in controlled experimental settings. Predation was documented through in vivo video recordings and supported by species-level identification of both predator and prey. These findings expand the currently recognized trophic interactions involving freshwater gastrotrichs and provide new insight into their ecological role within aquatic food webs.

The snake fauna of the Mediterranean islands has been shaped by multiple processes, including both natural and human-mediated dispersal. Various past human cultures and recent changes in trade and transportation have played a crucial role in the expansion of some species into insular environments. The snakes present on the Maltese archipelago are particularly emblematic of this complex mix of dispersal events. The European Cat Snake, Telescopus fallax (Fleischmann, 1831), forms a species complex widespread from the Balkans to the Middle East and across many eastern Mediterranean islands, regarded in most of the literature as introduced on the Maltese archipelago. Here we genetically investigated the Maltese populations of T. fallax using the mitochondrial marker Cytochrome b, with the aim of properly identifying their genetic affiliation and tracing their possible origin. The eight sequences obtained from the populations of Malta and Gozo shared the same mitochondrial haplotype and clustered together with the Balkan clade of T. fallax, thereby supporting their affiliation to the currently recognized nominotypical subspecies. The haplotype of the Maltese Cat Snake is identical to that of populations from the western Peloponnese and the island of Skyros (Sporades, Greece). The lack of variability found between the studied populations and some from southern Greece supports the hypothesis that this snake was introduced during historical times. The succession of many small Hellenic communities on the Maltese archipelago over the last few millennia suggests a possible Greek-mediated introduction; however, precisely because of the repeated presence of these influences over time, it is difficult to pinpoint the exact timing of introduction.

The genus Scolopendra is a taxonomically complex group, with species displaying intricate evolutionary radiation across Mediterranean islands. The present work aims to explore the diversity patterns of the Mediterranean banded centipede S. cingulata across Sicily, some surrounding islands, and Southern Calabria, investigating its genetic (COI and 28S) and phenotypic variation. Through extensive sampling and the analysis of 92 COI sequences from 82 sampling sites, three distinct structured lineages were identified in the study area: Sicily/Malta (SM), Eastern Peloritani Mountains (EP), and Aspromonte (As). Conversely, 28S sequences did not reveal the same genetic structure observed in the COI, probably due to the occurrence of introgression phenomena. Morphological assessments showed significant variation among clades. Colour pattern analysis revealed distinguishable morphotypes among the three clades. SM juveniles exhibit a unique light morphotype, contrasting with the dark dichromatic morphotype common to As and EP juveniles. These findings seem to suggest multiple colonisation events and prolonged isolation periods in Sicily, which shaped the current diversity of S. cingulata on the island. The genetic distinctiveness and apparent parapatric distribution of SM and EP, with limited evidence of admixture, highlight the need for further studies to fully understand the evolutionary history and potential taxonomic implications for this taxon.

Freshwater ecosystems are among the most severely affected environments by species loss caused by climate change and intense anthropogenic pressure. To preserve biodiversity, biomonitoring plays a key role by providing reliable data on biological diversity and ecological status. Environmental DNA (eDNA) metabarcoding has emerged as a powerful and non-invasive alternative to traditional morphology-based sampling and identification methods. This study represents the first application of eDNA analysis to assess the invertebrate communities in three Sicilian Lakes: Poma, Piana degli Albanesi and Scanzano. Water samples were collected at two points in each lake and after filtration with nitrocellulose membranes, eDNA was extracted and metabarcoding analysis was performed. A total of 27 species were identified, belonging to Phyla of Annelida, Arthropoda and Rotifera. Notably, the analysis revealed the presence of alien species (Daphnia parvula and Acanthocyclops americanus), a dangerous species associated with the transmission of viral diseases (Culex pipiens), and potential new records for Sicily (Stylaria lacustris, Platypalpus exilis, Pammene aurana, Limnephilus rhombicus). These results provide a preliminary snapshot of invertebrate biodiversity at these sites, demonstrating how eDNA has the potential to complement, but not replace, traditional methods, contributing to the assessment of ecosystem status.

Although often considered primarily hematophagous on mammalian blood, the leeches belonging to the genus Hirudo can feed on several other vertebrate hosts. However, to date, little is known about the feeding ecology of medicinal leeches in the wild, and the few available observations mostly deals with the European medicinal leech, Hirudo medicinalis. Since even closely related Hirudo species have different functional morphology and ecological preferences, the observations carried out on one species cannot be automatically generalized to the other medicinal leeches, and targeted surveys must be realised to better understand the feeding habits of these leeches. A wide geographical belt ranging from the Iberian Peninsula to the Caucasus and Central Asia is inhabited by the southern European medicinal leech, Hirudo verbana. Although quantitative data are missing, the species seems characterized by a general decline throughout its distribution range, whose causes are not fully understood. Accordingly, a better understanding of H. verbana dietary composition is crucial to characterise its role in the trophic webs of the ecosystems it inhabits, with important consequences for the correct management of the populations of the species. Here, we report the observation of Hirudo verbana feeding on fish in the wild in southern Italy. This observation constitutes one of the first direct evidences of the species using fish as host organisms, since to date wild H. verbena had been observed mostly feeding on amphibians and mammals. Such information is useful to better characterise the diet of the wild populations of H. verbana, and to understand the trophic resources which could be exploited by the species in different ecosystems. Finally, a review of all the available evidence dealing with the use of fish as hosts organisms by Hirudo spp. is carried out.

The Maghreb region of North Africa, located at the intersection of the Palaearctic and Afrotropical zones, is a biodiversity hotspot for terrestrial and freshwater taxa, including the freshwater crab of genus Potamon Savigny, 1816. Recent molecular studies have suggested the presence of two distinct Potamon species in the region: Potamon algeriense Bott, 1967, and an as-yet undescribed taxon, Potamon sp. However, comprehensive data on their distribution, genetic structure, and conservation status are still lacking. In the present study, we integrate new field collections from Algeria and Morocco (2021–2023) with molecular analyses of mitochondrial (COI, ND1) and nuclear (28S rDNA) markers to assess species boundaries and genetic diversity within Potamon across the Maghreb. Phylogenetic reconstructions based on Maximum Likelihood and Bayesian Inference consistently support the presence of two well-differentiated Potamon lineages in the region, corresponding to P. algeriense in western and central Maghreb, and Potamon sp. in eastern Algeria and Tunisia. While Potamon sp. exhibits low intra-specific genetic variation, P. algeriense displays a deeply structured mitochondrial lineage composition, forming four geographically coherent subclades, each corresponding to distinct hydrological regions. In light of this, it would be advisable to revise the IUCN assessment to include both species and updated information on their distribution.

The information on Recent non-marine ostracod faunas of the north-eastern part of the Afrotropical region is still limited. Here we report the first record of ostracods from the Dahlak Archipelago, a group of small islands located in the southern part of the Red Sea off the Eritrean coast. Specimens were obtained by hatching in the laboratory of diapausing eggs occurring in dried mud collected in temporary freshwater ponds, following the so-called “Sars’ method”. A total of five species were found, including two species new to science, of which four belong to the family Cyprididae (Cypris galefensis, Plesiocypridopsis newtoni, Heterocypris sp., and Chrissia martensi n.sp.) and one to the family Ilyocyprididae (Ilyocypris dahlakensis n.sp.). A detailed description of the morphology of valves and soft parts is given, and COX1 sequences were obtained for four species. Cypris galefensis was so far only known for its type locality in Somalia with a population containing both males and females, whereas our samples consisted exclusively of females. Plesiocypridopsis newtoni, a species characterised by a wide geographic distribution and previously known to occur also in the Afrotropical region, shows marked variability in the prehensile palps of males, as evidenced by comparing the specimens from this study with descriptions available in the literature. The genus Heterocypris (with 15 species) and the genera of the two new species described here, Chrissia (with 17 species) and Ilyocypris (with four species), have been previously reported from this biogeographic region as well. The specimens analysed of Chrissia martensi n.sp. were all females, none of which had sperm inside the carapace, indicating the possibility of parthenogenetic reproduction in this species. A peculiar sexual dimorphism in the valve morphology characterises Ilyocypris dahlakensis n.sp., with females having a straight posterior margin, forming a right angle at the ventral anterior edge. Rehydration of dry sediments collected from arid areas where wet periods are short and often unpredictable has proven to be a successful method for describing aquatic invertebrate biodiversity.

A qualitative and quantitative analysis of 18 elements was conducted on Procambarus clarkii and its environmental samples to evaluate its potential as a bioindicator species. Analysis of biological samples was carried out to both assess the safety of the use of raw materials and, together with environmental samples, to assess the contamination status of the sampled sites. Significant differences highlighted by the PERMANOVA, HCA and PCA analyses confirmed the valid use of P. clarkii as a bioindicator of the health status of the studied ecosystem. The bioaccumulation factor (BAF) and the biotic sediment accumulation factor (BSAF), except in a few cases, reported values below the bioaccumulative criterion and showed the highest BAF values for manganese, iron and barium in the exoskeleton while the highest BSAF values concerned mercury, copper and zinc in the muscle and barium in the exoskeleton. These findings indicate that, for most of the trace elements (TEs), the extent of pollution at these sites is such that it does not result in significant bioaccumulation in the muscle and exoskeleton of P. clarkii. The TE concentration levels signalled mild contamination of the sampling sites, proving a good health status of the studied aquatic ecosystem. Finally, the results obtained in P. clarkii muscle were below the threshold limits of EU Regulation 2023/915 suggesting that these edible parts are safe for human consumption.

Marine hydrothermal ecosystems represent extreme environments connected to submarine volcanic areas characterized by vents, having high temperatures and particular chemical compositions. The hydrothermal marine system of Panarea, located in one of the seven small islands belonging to the Aeolian Archipelago (southern Tyrrhenian Sea), is characterized by a range of vents exhibiting diverse physical and chemical conditions. We aimed to analyze the microbial community of a peculiar hot spring belonging to the Panarea hydrothermal field, known as “Black Point” (BP), in two separate sampling expeditions (May and August). Our results demonstrated that the chemical–physical variations within this hydrothermal vent, such as temperature fluctuations, mineral content, and hydrothermal fluid dynamics, play a role in shaping the structure and diversity of microbial communities. The differences between the two sampling expeditions suggest that seasonal changes, i.e., in temperature, pH, and redox potential (Eh), could drive microbial community shifts over time.

The protection of the Vulnerable Marine Ecosystem identified by the presence of the critically endangered bamboo coral Isidella elongata has been recognized as an urgent task. Although some research has focused on the spatial distribution of this species, there is no information available on its connectivity and genetic structure. This is the first study to examine the genetic diversity pattern and inter-population connectivity ofI. elongata at the Mediterranean scale. The DNA-based approach for assessing the genetic diversity of 33 I. elongata samples collected in six different areas involved two mitochondrial markers (COI and MutS) and one nuclear marker (ITS2). Molecular results confirmed that all samples belonged to I. elongata and showed a scarce level intra-and inter-population mtDNA differentiation, whereas nuDNA data revealed genetic structuring. Furthermore, a Lagrangian model (forward-in-time simulations) was used to investigate the species larval connectivity under different sea current conditions. Our results suggest the presence of persistent pathways, supporting the self-sustaining nature of the populations, especially in the central Mediterranean Sea. This study identifies the main corridors of connectivity for I. elongata in the Mediterranean Sea, highlighting the importance of including such information in the implementation of fishery management measures.

A major threat to biodiversity is represented by Invasive Alien Species (IAS), particularly on freshwater ecosystems, which are already heavily altered by human activities. Two of the most pernicious IAS are the eastern and western mosquitofish, i.e., Gambusia holbrooki and G. affinis. These two poeciliids are morphologically very close to each other, and soon after their formal description, G. holbrooki was considered a subspecies of G. affinis. In the following years, several studies proved that these two entities belonged to two different species; nevertheless, it was only at the end of the 1990s that their separate taxonomic status was re-established. In the 1920s and 1930s, both G. holbrooki and G. affinis were asynchronously introduced from the United States into Europe and subsequently translocated globally as biocontrol agents of the malaria vector (i.e., the larvae of the Anopheles mosquitoes), with dramatic consequences for the inland water native fauna. However, due to taxonomic uncertainties and nomenclatural instability, for years, there were doubts about which Gambusia species had been introduced in different regions. The first available molecular studies confirmed the occurrence of G. holbrooki in Europe, but no evidence confirming the occurrence of G. affinis was found. Despite this, some records report the occurrence of western mosquitofish in Italy and Malta. Considering the negative effects that the mosquitofish has on the native biota, it is of paramount importance to know the precise biological diversity of the native and non-native species to better implement environmental management strategies to properly preserve the already-fragile waterbodies. Therefore, to check for the possible occurrence of G. affinis in Italy and Malta, we conducted extensive sampling in Sicily (Italy) and in the Maltese archipelago, aiming to verify the identity of Gambusia populations occurring in the study area. Based on sequences of the mitochondrial cytochrome b gene, we consistently observed the occurrence of only G. holbrooki in the investigated area, finding, almost exclusively, the most common haplotype known for the species in the whole invaded range (i.e., “HOL1”).

Hydrothermal springs (HTSs) are unique environments characterized by the emergence of geothermally heated groundwater that often releases large amounts of dissolved minerals. Despite the interest in HTSs, the microbial composition of these sites remains largely under-explored, particularly concerning the interactions between marine invertebrates and microorganisms. The shallow HTSs near the west coast of Sicily (Italy), with a constant temperature of 31 °C throughout the year, host two invertebrates: the nudibranch Peltodoris atromaculata (P. atromaculata) and the sponge Petrosia ficiformis (P. ficiformis). Using Next-Generation Sequencing (NGS) of the bacterial 16S rRNA gene marker, the bacterial communities of these invertebrates were analyzed. Microbial diversity was higher in the P. atromaculata mantle and in P. ficiformis than in the P. atromaculata gut, with notable differences in families such as Caldilineaceae, Endozoicomonadaceae, Alteromonadaceae, and Enterobacteriaceae, showing abundance variations among the samples. Unique bacterial signatures, including Mycoplasmataceae, Endozoicomonadaceae, and Alteromonadaceae in the gut and Enterobacteriaceae in the mantle of P. atromaculata, were also identified. These findings provide valuable insights into the bacterial diversity of these two marine invertebrates, which are recognized as bioindicators of environmental conditions.

The frequent introduction and rapid spread of invasive alien species (IAS) along with the limited resources available for their management highlight the need to adopt simple and effective methods for prioritizing management efforts. Here, we propose a technically simple model for prioritizing management actions, using Sicily (southern Italy) as a case study. Despite its invasion being relatively recent and the species not yet widespread, the highly invasive red swamp crayfish Procambarus clarkii proved to be able to colonize different habitat types on this Mediterranean island. We adopted a multicriteria analysis method based on geographic information systems (GIS) to identify both the vulnerability of different areas to its invasion, the likelihood of their invasion, and the impact that the occurrence of the red swamp crayfish might have on habitats or species of conservation relevance. The data used in our analysis are routinely available to local administrations and can be easily processed to map the most vulnerable areas for biodiversity protection. The simplicity of the model makes it particularly suitable for local administrative bodies to plan and implement effective invasive species management interventions, optimizing time and costs and allowing the development of concrete nature conservation actions.

The Strait of Sicily represents a biogeographically rich and complex region. The diverse geological origin and past continental connection of its islands have shaped a highly heterogeneous fauna, mainly composed of both African and European taxa. The Italian sea-slater, Ligia italica (Fabricius, 1798), is a small isopod inhabiting rocky shores of the Mediterranean Sea, Black Sea, and Atlantic Ocean. Despite its wide distribution, the phylogeography of this species is poorly understood, with limited available data suggesting a remarkable level of cryptic diversity. In this study, we investigated the mitochondrial genetic diversity (COX1) of L. italica across nine Italian and Maltese islands across the Strait of Sicily, aiming to clarify the biogeographic patterns underlying the distribution of these insular populations. Our results reveal an unexpectedly high genetic diversity within our study area, with eight different haplogroups, each characterized by low internal genetic variation and mutual distances ranging from 5.5% to 17.9%. These values are comparable to those associated with species-level rank within the genus Ligia. Overall, the phylogenetic relationships between the lineages appear well supported; however, the same relationships are not clearly correlated with geographic proximity or connectivity among the sampled localities. The distribution patterns of some of the detected haplogroups suggest possible passive dispersal mechanisms (e.g., rafting), while others indicate more intricate biogeographic scenarios. The overall diversity of L. italica within the Strait of Sicily, as well as the unclear origin of some insular populations, cannot be fully explained with the current data. In particular, the high genetic structure observed within the Maltese Archipelago, may partially reflect human-mediated dispersal (e.g., maritime transport), possibly involving source populations that remain unsampled or genetically uncharacterized. Our results highlight that the Strait of Sicily can be considered a diversity hot spot for L. italica and support the designation of this taxon as a putative species complex, with a cryptic diversity worthy of an exhaustive taxonomic revision.

In the published publication [...]

Olindiid freshwater jellyfishes of the genus Craspedacusta Lankester, 1880 are native to eastern Asia; however, some species within the genus have been introduced worldwide and are nowadays present in all continents except Antarctica. To date, there is no consensus regarding the taxonomy within the genus Craspedacusta due to the morphological plasticity of the medusa stages. The species Craspedacusta sowerbii Lankester, 1880 was first recorded in Italy in 1946, and until 2017, sightings of the jellyfish Craspedacusta were reported for 40 water bodies. Here, we shed new light on the presence of the freshwater jellyfishes belonging to the genus Craspedacusta across the Italian peninsula, Sardinia, and Sicily. First, we report 21 new observations of this non-native taxon, of which eighteen refer to medusae sightings, two to environmental DNA sequencing, and one to the finding of polyps. Then, we investigate the molecular diversity of collected Craspedacusta specimens, using a Bayesian analysis of sequences of the mitochondrial gene encoding for Cytochrome c Oxidase Subunit I (mtDNA COI). Our molecular analysis shows the presence of two distinctive genetic lineages: (i) a group that comprises sequences obtained from populations ranging from central to northern Italy; (ii) a group that comprises three populations from northern Italy—i.e., those from the Lake Levico, the Lake Santo of Monte Terlago, and the Lake Endine—and the single known Sicilian population. We also report for the first time a mtDNA COI sequence obtained from a Craspedacusta medusa collected in Spain.

Plutonium zwierleini is a large plutoniumid centipede of great evolutionary interest, occurring with isolated populations along the western Mediterranean area, from Spain to Italy. Due to its rarity and the extreme paucity of available records, P. zwierleini is among the least known Mediterranean chilopods, and scarce information is currently available on its ecology and natural history. Based on an extensive sampling effort carried out in Sicily between 2022 and 2023, we here provide additional occurrence localities for the species across Sicily, and new insights into its ecology. Overall, 29 novel Sicilian records of P. zwierleini, scattered across 21 localities, were collected thus increasing its known Sicilian distribution area by 117%, and the number of localities by 110%. The species was found in a wide range of habitats such as open areas, woods, buildings, and caves, characterizing Plutonium zwierleini as a habitat generalist, whose fine ecological preferenda need to be further explored. Moreover, to explore the diet and behaviour of the species, some specimens were kept in captivity. The captive individuals fed mostly on dead or poorly mobile soft-bodied prey and inert food, without ever displaying predatory behaviour; this suggests that, contrarily to what is currently assumed, P. zwierleini might be a scavenger rather than a predator. The potential distribution of Plutonium zwierleini in Sicily was inferred based on georeferenced occurrence records and climatic variables. The implemented MaxEnt model forecasts the possible occurrence of P. zwierleini on the whole island, with the single exception of its south-easternmost part, possibly due to the local pattern of precipitation seasonality. We hope that the present work might pave the way for further surveys aimed at a better understanding of the ecology of Plutonium zwierleini and the collection of new data in the other regions inhabited by this secretive species.

A five-year of monitoring (2018–2022) of the loggerhead sea turtle Caretta caretta nests in “Pozzolana di Ponente” beach on Linosa Island (Pelagie Archipelago, Italy) is here reported. To explore how temperatures affect the hatching success and the possible occurrence of any malformation in hatchlings, incubation temperature values were recorded using data loggers positioned at depths of 5 and 35 cm (for each nest) from the surface, approximately 0.5 m from the nest chamber. The obtained results highlighted important issues related to the success of hatching and the incidence of body anomalies. The temperatures recorded at different depths near the nests (5 and 35 cm) in some periods of incubation of the eggs were above optimal development temperature (i.e., ~33°C), causing high mortality rates, especially during the first two years of the survey (2018–2019). In the next three years (2020–2022), the implementation of shading cover cloths of the nests increased the survival rate and decreased the incidence of malformed individuals. Furthermore, atmospheric temperature data were extrapolated from the “Copernicus Climate Change” web service and included in our analyses to assess any changes over the timeframe analysed. Over five years (2018–2022), the average atmospheric temperature increased slightly by 1.7°C. In light of global warming, the implementation of effective and low-cost mitigation activities, such as the use of shade cloth covers to protect the nests from overheating, should be considered a suitable conservation action.