Fabio Scarpa

Mitochondrial DNA reveals genetic structuring of Pinna nobilis across the Mediterranean Sea.

Pinna nobilis is the largest endemic Mediterranean marine bivalve. During past centuries, various human activities have promoted the regression of its populations. As a consequence of stringent standards of protection, demographic expansions are currently reported in many sites. The aim of this study was to provide the first large broad-scale insight into the genetic variability of P. nobilis in the area that encompasses the western Mediterranean, Ionian Sea, and Adriatic Sea marine ecoregions. To accomplish this objective twenty-five populations from this area were surveyed using two mitochondrial DNA markers (COI and 16S). Our dataset was then merged with those obtained in other studies for the Aegean and Tunisian populations (eastern Mediterranean), and statistical analyses (Bayesian model-based clustering, median-joining network, AMOVA, mismatch distribution, Tajima’s and Fu’s neutrality tests and Bayesian skyline plots) were performed. The results revealed genetic divergence among three distinguishable areas: (1) western Mediterranean and Ionian Sea; (2) Adriatic Sea; and (3) Aegean Sea and Tunisian coastal areas. From a conservational point of view, populations from the three genetically divergent groups found may be considered as different management units.

Patterns of spatial genetic variation in Patella ulyssiponensis: insights from the western Mediterranean marine ecoregion

Patterns of genetic variation in marine species reflect the interplay of species-specific traits, oceanographic features, historical processes and selection. In the Atlantic–Mediterranean regions, Patella ulyssiponensis (Mollusca: Gastropoda) was previously used as a model to investigate these patterns. Our study gained insight into the genetic patterns of P. ulyssiponensis in the western Mediterranean marine ecoregion (WME), by means of ISSRs and COI. We evaluated the genetic structure of the WME with respect to the Atlantic and eastern Mediterranean, as well as the occurrence of further structuring within this ecoregion. Both population- and individual-based analysis evidenced that WME does not appear to be sharply isolated from the adjacent regions. Within the WME, P. ulyssiponensis displays a pattern of genetic structure that may reflect a chaotic patchiness scenario: structuring is neither related to coastal distance nor to other factors that may constrain dispersal. Compared to the congener P. ferruginea, P. ulyssiponensis shows weaker spatial genetic structure, which may reflect a higher dispersal potential coupled with greater population effective size. Whilst other processes that may have influenced the genetic pattern in the WME remain to be cleared, a recent range expansion coupled with species-specific traits favouring larval dispersal may have contributed to the genetic structuring.

Molecular support for morphology‐based family‐rank taxa: The contrasting cases of two families of Proseriata (Platyhelminthes)

Representatives of the Meidiamidae and Otomesostomidae (Platyhelminthes: Proseriata) are seldom encountered, and the monophyly and phylogenetic relationships of these families have never been assessed on molecular basis. Here, we present the first exhaustive molecular study of Proseriata at the family level, including species belonging to the genera Meidiama and Yorknia (Meidiamidae), and Otomesostoma auditivum (Otomesostomidae), using 18S and 28S genes as markers. We performed phylogenetic analyses (Maximum Likelihood [ML] and Bayesian Inference [BI] methods) and species delimitation methods (Single/Multiple Threshold‐Generalized Mixed Yule Coalescent [ST/MT‐GMYC] and Poisson Tree Processes [PTP/bPTP]). The taxon Meidiamidae was not supported, since the type species (Meidiama lutheri) and Meidiama etrusca sp. n. are nested within the Archimonocelididae, formerly restricted to specialized cnidarian feeders. Species belonging to the genus Yorknia resulted genetically well separated from species of Meidiama and from the rest of Archimonocelididae. The new family‐level taxon Yorkniidae fam. n. is thus here introduced, to include the type species of Yorknia (Yorknia aprostatica), and six new species, five of which are formally described here. Otomesostoma auditivum, representative of Otomesostomidae, the only exclusively freshwater taxon of the Proseriata, is the sister taxon of the predominantly marine Apingospermata. This result is not conflictual with the family level attributed to Otomesostomidae on morphological grounds, but it raises speculations on the marine versus freshwater origin of Apingospermata.

Fistularia commersonii (Teleostea: Fistulariidae): walking through the Lessepsian paradox of mitochondrial DNA

Abstract The Mediterranean Lessepsian migrations excite the interest of biologists who are devoted to inferring the effects of selection on the genetic structure of immigrants. The bluespotted cornetfish Fistularia commersonii is an Indo-Pacific species that was first recorded in the Levantine cost of Mediterranean, and within a few years, it rapidly expanded throughout the entire basin. Studies on its genetic variability, performed via mitochondrial sequencing of the Mediterranean specimens, suggest that a limited number of mitochondrial lineages passed through the Suez Canal. However, nuclear markers provide a scenario, with a high genetic variability among the Mediterranean F. commersonii migrants, along with the occurrence of haplotype sharing between the Mediterranean and the Red Sea. The aim of this study was to enlarge the number of Mediterranean sites in order to evaluate if the rapid expansion and different patterns of spread of F. commersonii in the basin could have led to a genetic structuring. The analysis was carried out by sequencing mitochondrial D-loop I in individuals from Sardinia, Sicily, Tunisia, Lampedusa, Libya and Lebanon. Sequences available from previous studies were included in the data set, allowing us to obtain a data set that likely represents the entire distribution range of the species. Results suggest the possible occurrence of two mitochondrial lineages involved in the Mediterranean invasion of F. commersonii, a bottleneck may have caused a loss in the genetic variation, leading to the fixation of specific lineages as an adaptive response to the new environmental conditions.

First insights on the mitochondrial genetic variability of Lightiella magdalenina (Crustacea), the sole Mediterranean cephalocarid species

BackgroundHere we report the first insight into the mitochondrial (Cytochrome c Oxidase subunit I - COI and Cytochrome b - Cyt b) genetic variation of the only Mediterranean cephalocarid Lightiella magdalenina.FindingsCOI sequences provide a scenario of low intraspecific variability, while significant genetic divergence occurs between L. magdalenina and L. incisa. Interestingly, Cyt b sequences reveal a higher degree of intraspecific variability, with no shared haplotypes between the sites considered.ConclusionsIn the future, COI and Cyt b molecular markers could be used as valuable tools to shed new light into the extant species within the genus Lightiella thus providing molecular support to the taxonomical identifications carried out on a morphological basis.

New insights on the genus Otoplana Du Plessis, 1889 (Platyhelminthes: Proseriata), with description of two new species from the Canary Islands

Two new species of Otoplana (Proseriata: Otoplanidae) from the Canary Islands are here described: Otoplana norenburgi sp. nov. and Otoplana didomenicoi sp. nov. These new species are distinguished from their congeners by unique features of the sclerotized structures of the copulatory organ, in particular of the aculeus, swollen proximally in O. norenburgi sp. nov. and lanceolate in shape in O. didomenicoi sp. nov. Specimens of the latter species were also found in South Portugal. Canarian and Portuguese specimens show poor genetic distinction based on the markers used, hinting to a remarkable dispersal power for a mesopsammic organism. New information is given on the “accessory male canal”, a putative autapomorphy for the genus Otoplana. Its functions and connections with genital systems are discussed, in the light of new data on the molecular phylogeny of the family Otoplanidae presented. The Mediterranean specimens of Otoplana sequenced, morphologically attributed to O. truncaspina, O. bosporana, O. falcataspina, and O. labronica, did not show genetic distinction, urging for a reconsideration of the status of the Mediterranean taxa.

Cytochrome c oxidase subunit I variability in Ruditapes decussatus (Veneridae) from the western Mediterranean

Abstract Ruditapes decussatus (Linnaeus, 1758) (Veneridae) is an Atlanto-Mediterranean bivalve whose populations have experienced reductions and, in some instances, hybridisation with allochthonous R. philippinarum. Acquisition of additional genetic knowledge concerning the present R. decussatus populations is essential to address adequate conservation plans for this species. For this purpose, we analysed a portion of the mtDNA cytochrome c oxidase subunit I (COI) region in populations from the western Mediterranean, where this species represents a harvested fishery resource. Our analyses revealed an overall lack of genetic structure within the western Mediterranean area, and the occurrence of mtDNA substructuring between the Aegean and Marmara seas and the remaining populations from the whole Mediterranean basin and the South European Atlantic coast. The results obtained for populations from Sardinia, where extensive restocking programmes have not been reported and where R. philippinarum is rare and localised, suggest that intensive harvesting and potential dispersal alone may have been able to shape the genetic variation identified in the local R. decussatus populations.

Genetic diversity of the haemagglutinin (HA) of human influenza a (H1N1) virus in montenegro: Focus on its origin and evolution

In 2009 an influenza A epidemic caused by a swine origin H1N1strain, unusual in human hosts, has been described. The present research is aimed to perform the first phylogenetic investigation on the influenza virus A (H1N1) strains circulating in Montenegro, from December 1, 2009, when the first case of death due to H1N1 was confirmed, and the epidemic began causing a total of four fatalities. The phylogenetic analysis of the strains circulating showed the absence of a pure Montenegrin cluster, suggesting the occurrence of multiple re‐introductions in that population from different areas till as far as the early 2010. The time to most recent common ancestor (TMRCA) for the complete dataset has been dated in early 2008, pre‐dating the first Montenegrin identification of H1N1 infection. These data suggest that virus was spreading undetected, may be as a consequence of unidentified infections in returning travelers. Anyhow, the estimated TMRCA of Montenegrin strains is fully consistent to that found in different areas. Compatibly with the time coverage of the study period here analyzed, molecular dynamic of Montenegrin strains follows similar trend as in other countries. J. Med. Virol. 88:1905–1913, 2016.

First record of Esox cisalpinus (Teleostea: Esocidae) in Sardinia with insight on its mitochondrial DNA genetic variability

Abstract Esox cisalpinus (Teleostea: Esocidae) (syn. Esox flaviae) is an Italian freshwater autochthonous fish, whose originary range is limited to the Northern and Central Italy. However, this species has historically been introduced in several areas of Southern Italy, mainly for recreational purposes. In this paper we report the first record of E. cisalpinus on the Sardinia island (Western Mediterranean, Italy), where the species has been recently introduced at least in one lake. The species identification and the population dynamics analysis were performed using mitochondrial markers. The level of genetic variability, compared to those of other peninsular populations of E. cisalpinus, was surprisingly high, and several never-before-described haplotypes were found. A total of 10 mtDNA haplotypes were found. Demographic analysis is suggestive of a population expansion. We hypothesise that E. cisalpinus has been introduced in the Sardinian lake by the releasing of a conspicuous number of individuals. Given the conservational and recreational interest that E. cisalpinus arouses, it would be advisable that Sardinian government focuses in the near future also on management measures of its Sardinian population.