Dino Scaravelli

Thyroid hormones as a potential early biomarker of exposure to 4-nonylphenol in adult male shubunkins (Carassius auratus) ☆

Nonylphenol, an estrogenic-like compound, can induce vitellogenin synthesis in males and immature Teleostean species, but little is known about its effects on thyroid hormones balance. The present study evaluated the potential effects of a single acute exposure to nonylphenol (i.p. injected) on the thyroid and reproductive axis of 250 shubunkins (Carassius auratus). Plasma levels of thyroid hormones were quantified immunoenzymatically by ELISA assay. Nonylphenol induced a significant decrease of thyroxin levels, whereas no effect on triiodothyronine concentrations was detected. No histopathological changes were detected in thyroid or testes. The toxicological data confirmed that nonylphenol exerts an estrogenic effect on male fish. In addition, nonylphenol was suspected to inhibit the thyroid hormones balance, suggesting the thyroid should be included among the other endocrine glands susceptible to endocrine disruption.

What Story Does Geographic Separation of Insular Bats Tell? A Case Study on Sardinian Rhinolophids

Competition may lead to changes in a species’ environmental niche in areas of sympatry and shifts in the niche of weaker competitors to occupy areas where stronger ones are rarer. Although mainland Mediterranean (Rhinolophus euryale) and Mehely’s (R. mehelyi) horseshoe bats mitigate competition by habitat partitioning, this may not be true on resource-limited systems such as islands. We hypothesize that Sardinian R. euryale (SAR) have a distinct ecological niche suited to persist in the south of Sardinia where R. mehelyi is rarer. Assuming that SAR originated from other Italian populations (PES) – mostly allopatric with R. mehelyi – once on Sardinia the former may have undergone niche displacement driven by R. mehelyi. Alternatively, its niche could have been inherited from a Maghrebian source population. We: a) generated Maxent Species Distribution Models (SDM) for Sardinian populations; b) calibrated a model with PES occurrences and projected it to Sardinia to see whether PES niche would increase R. euryale’s sympatry with R. mehelyi; and c) tested for niche similarity between R. mehelyi and PES, PES and SAR, and R. mehelyi and SAR. Finally we predicted R. euryale’s range in Northern Africa both in the present and during the Last Glacial Maximum (LGM) by calibrating SDMs respectively with SAR and PES occurrences and projecting them to the Maghreb. R. mehelyi and PES showed niche similarity potentially leading to competition. According to PES’ niche, R. euryale would show a larger sympatry with R. mehelyi on Sardinia than according to SAR niche. Such niches have null similarity. The current and LGM Maghrebian ranges of R. euryale were predicted to be wide according to SAR’s niche, negligible according to PES’ niche. SAR’s niche allows R. euryale to persist where R. mehelyi is rarer and competition probably mild. Possible explanations may be competition-driven niche displacement or Maghrebian origin.

TOXICITY OF SEA ALGAL TOXINS TO HUMANS AND ANIMALS

Marine algal toxins are responsible of more than 60000 intoxication/year, with an overall mortality of about 1.5%. Human intoxications are due to consumption of seafood and respiratory exposure to aerosolized toxins. Algal toxins are also responsible for extensive die-offs of fish and shellfish, as well as mortality in seabirds, marine mammals and other animals depending on marine food web. Lots of information are available concerning acute intoxications, while little is known about environmental health effects of chronic exposure to low levels of algal toxins. Toxins are produced by two algal groups, dinoflagellates and diatoms, representing about 2% of known phytoplankton species (60–80 species out of 3400–4000) and can reach humans directly (via consumption of shellfish) or through food web transfer to higher trophic levels (zooplankton and herbivorous fish). Most toxins are neurotoxins and all are temperature stable, so cooking does not ameliorate toxicity in contaminated seafoods; five seafood poisoning syndromes exists: paralytic shellfish poisoning, neurotoxic shellfish poisoning, ciguatera fish poisoning, diarrhetic shellfish poisoning, and amnesic shellfish poisoning.

Post-mortem investigations on a leatherback turtle Dermochelys coriacea stranded along the Northern Adriatic coastline

Leatherback sea turtles Dermochelys coriacea are regularly reported in the Mediterranean Sea but rarely reach the northern Adriatic Sea. In the summer of 2009, a well-preserved carcass of an adult female of this species was found dead along the coast of Lido di Venezia. A complete necropsy was carried out, along with evaluation of levels of tissue trace elements. The the post-mortem revealed acute severe bacterial gastroenteritis caused by Photobacterium damselae ssp. piscicida, an opportunistic agent that infected an apparently debilitated animal weakened by ingested plastic debris. High levels of heavy metals (Hg, Pb, Cd and As) found in the liver and kidneys might have contributed to the animals demise. These findings support previous indications that marine debris is one of the major threats to marine animals, particularly for critically endangered species such as the leatherback turtle.

Analysis of stranded sea turtles in the north-western Adriatic Sea

Abstract Through systematic recording of stranded individuals, it was shown that marine turtles regularly occur in the Upper Adriatic Sea. All 443 specimens examined belonged to the Loggerhead Turtle, Caretta caretta. The highest numbers are found during the summer months (July–September), the lowest in the cold season. Most individuals are juveniles, suggesting that Loggerheads use the Upper Adriatic Sea primarily as foraging area until they reach maturity. The northwester Adriatic Sea seems not to play an important role as a wintering and hibernation area, and no important role at all for adults. In 1999, exceptionally high numbers of Loggerhead Turtles were recorded (n = 95); most of them were smaller than 40 cm Curved Carapace Length, and thus smaller than the average of other years. Two Loggerhead Turtles recovered in the Adriatic Sea had been tagged at the nesting grounds at Zakynthos, Greece.

Toxicity of Fresh Water Algal Toxins to Humans and Animals

Algae and cyanobacteria are responsible of the presence of toxins in fresh waters. Algae are considered less dangerous than cyanobacteria, because even if they can proliferate quite intensively in eutrophic fresh waters, they rarely accumulate to form dense surface blooms like blue-green algae do. Thus the toxins they produce do no accumulate to levels high enough to become hazardous to human and animals health.

Vitellogenin (VTG) conservation in sea turtles: anti-VTG antibody in Chelonia mydas versus Caretta caretta.

Vitellogenin (VTG) is considered as a marker of endocrine disruption. A Western blot method for VTG quantification in Caretta caretta turtle plasma was developed using anti‐VTG antibody for Chelonia mydas. A screening of samples (n = 61) collected in the southern Mediterranean Sea around Lampedusa Island, Italy, was performed. The antibody showed a good cross‐reactivity with C. caretta VTG, suggesting a certain conservation of the core of the protein in different sea turtle species. The optimal operative condition for Western blot analysis consists of using diluted plasma at 1:50. In field samples, a certain mismatch with morphological sexing was observed, and VTG was detected in young animals. These results suggest the possibility of a precocious activation of VTG‐encoding genes before sexual maturation and/or exposure to endocrine disrupter substances.

Circum-Mediterranean phylogeography of a bat coupled with past environmental niche modeling: A new paradigm for the recolonization of Europe?

The isolation of populations in the Iberian, Italian and Balkan peninsulas during the ice ages define four main paradigms that explain much of the known distribution of intraspecific genetic diversity in Europe. In this study we investigated the phylogeography of a wide-spread bat species, the bent-winged bat, Miniopterus schreibersii around the Mediterranean basin and in the Caucasus. Environmental Niche Modeling (ENM) analysis was applied to predict both the current distribution of the species and its distribution during the last glacial maximum (LGM). The combination of genetics and ENM results suggest that the populations of M. schreibersii in Europe, the Caucasus and Anatolia went extinct during the LGM, and the refugium for the species was a relatively small area to the east of the Levantine Sea, corresponding to the Mediterranean coasts of present-day Syria, Lebanon, Israel, and northeastern and northwestern Egypt. Subsequently the species first repopulated Anatolia, diversified there, and afterwards expanded into the Caucasus, continental Europe and North Africa after the end of the LGM. The fossil record in Iberia and the ENM results indicate continuous presence of Miniopterus in this peninsula that most probably was related to the Maghrebian lineage during the LGM, which did not persist afterwards. Using our results combined with similar findings in previous studies, we propose a new paradigm explaining the general distribution of genetic diversity in Europe involving the recolonization of the continent, with the main contribution from refugial populations in Anatolia and the Middle East. The study shows how genetics and ENM approaches can complement each other in providing a more detailed picture of intraspecific evolution.

Trace metal concentration in wild avian species from Campania, Italy

AbstractThis study was conducted to determine heavy metals concentrations in tissues of 94 birds belonging to different species from coastal areas of Naples and Salerno (Southern Italy) in order to provide baseline data concerning trace element levels in wild birds living in or close to an area characterized by high anthropogenic impact. Additional aim of this study was to verify if diet influenced metal accumulation, so birds were classified as birds of prey, fish eating birds and insectivorous birds.Kidney was the primary organ for Cd accumulation in all groups considered, Pb was accumulated preferentially in bone, whereas Hg showed high values in liver of fish eating birds. Zn showed the highest mean concentrations, while Cu levels were one order of magnitude less. The variance analysis with respect to feeding habits disclosed only a lower accumulation of Hg in insectivores with respect to the other groups. For all metals, the concentrations measured in tissues should be considered indicative of chronic exposure to low, “background” environmental levels and/or to the presence of low bioavailable metals in the environment. In addition, metal levels were not of toxicological concern, being always well below the toxic thresholds defined for each metal.

Surveillance for antiviral resistance among influenza viruses circulating in Algeria during five consecutive influenza seasons (2009-2014)

Influenza season 2007/2008 was marked by a worldwide emergence of oseltamivir‐resistant A(H1N1) viruses possessing a mutation in the neuraminidase gene causing His‐to‐Tyr substitution at amino acid position 275 (H275Y). These strains were isolated in Algeria where 30% of seasonal A(H1N1) viruses harbored the H275Y mutation. Emergence of resistant viruses to currently approved antiviral drug determined the need for antiviral susceptibility monitoring in Algeria especially that oseltamivir is currently used in hospitals of some provinces of the country for treatment of influenza in populations at risk. The aim of the present study is to investigate the sensitivity of circulating influenza viruses in Algeria to oseltamivir. We present 5‐year local surveillance results from 2009/2010 influenza season to 2013/2014 influenza season. We tested the sensitivity to oseltamivir of 387 human influenza A and B viruses isolated in Algeria. Determination of IC50 values were performed using the fluorogenic MUNANA substrate. To detect the H275Y mutation in the neuraminidase of the A(H1N1) strains we performed a real‐time RT‐PCR allelic discrimination analysis. The obtained results showed that all influenza A(H1N1)pdm09, A(H3N2), and B viruses studied remained susceptible to oseltamivir. This is the first study on influenza antiviral susceptibility surveillance in Algeria. Obtained results allow establishing a baseline data for future studies on antiviral resistance emergence worldwide. Our report highlights the importance of a continued and active monitoring of circulating viruses in Algeria for strengthens collaboration within the Global Influenza Surveillance and Response System.