Predation on two brachiopods, Joania cordata and Argyrotheca cuneata, from an offshore reef in the Tyrrhenian Sea

Predator holes in empty shells of Joania cordata and Argyrotheca cuneata (Brachiopoda: Megathyrididae) collected in the marine protected area “Secche di Tor Paterno”, central Tyrrhenian Sea, Italy (41°35′N–12°20′E, at depths of 20–28?m), were analyzed. Predation intensity was low but appreciable, with the more common species J. cordata preyed on more frequently (6.7?%) than A. cuneata (3.8?%). Three main types of holes were recognized: (1) cylindrical drill holes with a circular outline, (2) larger irregular holes with a jagged outline, and (3) small holes at the bottom of depressions in the shell. They were probably produced by muricid gastropods, crabs, and Foraminifera, respectively. The large, irregular holes were the most common type in both brachiopod species. Evidence for predator selectivity with respect to which valve, the position of the hole on the valve, and the size of the brachiopod with respect to those available was assessed. The ventral valve, the postero-medial portions of both valves, and larger (J. cordata) or medium-sized (A. cuneata) shells were more frequently holed.     

Quantitative Real-Time PCR and Digital PCR to Evaluate Residual Quantity of HAV in Experimentally Depurated Mussels

Food and Environmental Virology - Kinetics of hepatitis A virus (HAV) accumulation and depuration from mussels (Mytilus galloprovincialis) was studied in an experimental depuration system....     

Study of the severity of hybrid mixture explosions and comparison to pure dust-air and vapour-air explosions

The explosion behaviour of heterogeneous/homogeneous fuel-air (hybrid) mixtures is here analysed and compared to the explosion features of heterogeneous fuel-air and homogeneous fuel-air mixtures separately.Experiments are performed to measure the pressure history, deflagration index and flammability limits of nicotinic acid/acetone-air mixtures in a standard 20 L Siwek bomb adapted to vapour-air mixtures. Literature data are also used for comparison.The explosion tests performed on gas-air mixtures in the same conditions as explosion tests of dust-air mixtures, show that the increase in explosion severity of dust/gas-air mixtures has to be addressed to the role of initial level of turbulence prior to ignition.At a fixed value of the equivalence ratio, by substituting the dust to the flammable gas in a dust/gas-air mixture the explosion severity decreases. Furthermore, the most severe conditions of dust-gas/air mixtures is found during explosion of gas-air mixture at stoichiometric concentration.     

Effects of detrital non-native and native macroalgae on the nitrogen and carbon cycling in intertidal sediments

The decay of non-native and native seaweed mixing may modify sediment biogeochemistry and organic matter transfers within benthic food webs according to their composition and biomass. The non-native species Sargassum muticum was deliberately added to the sediment of an intertidal sandflat at different biomass and mixed to the native species Ulva sp. and Fucus vesiculosus. The sediment porewater was then ¹³C and ¹⁵N enriched to test whether both detrital diversity and biomass influenced the transfer of porewater carbon and nitrogen to the sediment and to the macrofauna consumers. More ¹⁵N-nitrogen was mobilized to sediments and macrofauna when the 3-species detrital mixing was buried, probably because this mixing provided species-specific compounds such as polyphenols due to the presence of S. muticum and F. vesiculosus, as well as large amounts of nitrogen due to the presence of Ulva. Our study revealed the importance of detrital diversity and non-native seaweeds for the nitrogen cycling in the benthic food web.     

Evaluation of Online Information Sources on Alien Species in Europe: The Need of Harmonization and Integration

Europe is severely affected by alien invasions, which impact biodiversity, ecosystem services, economy, and human health. A large number of national, regional, and global online databases provide information on the distribution, pathways of introduction, and impacts of alien species. The sufficiency and efficiency of the current online information systems to assist the European policy on alien species was investigated by a comparative analysis of occurrence data across 43 online databases. Large differences among databases were found which are partially explained by variations in their taxonomical, environmental, and geographical scopes but also by the variable efforts for continuous updates and by inconsistencies on the definition of “alien” or “invasive” species. No single database covered all European environments, countries, and taxonomic groups. In many European countries national databases do not exist, which greatly affects the quality of reported information. To be operational and useful to scientists, managers, and policy makers, online information systems need to be regularly updated through continuous monitoring on a country or regional level. We propose the creation of a network of online interoperable web services through which information in distributed resources can be accessed, aggregated and then used for reporting and further analysis at different geographical and political scales, as an efficient approach to increase the accessibility of information. Harmonization, standardization, conformity on international standards for nomenclature, and agreement on common definitions of alien and invasive species are among the necessary prerequisites.     

Presence of hydrocarbon-degrading bacteria in the gills of mussel Mytilus galloprovincialis in a contaminated environment: a mesoscale simulation study

A number of previous studies have shown that the relationships of symbiosis existing between mussels and microorganisms are directly dependent on the environmental conditions. However, little is known about existing relationships between mussels and bacteria in hydrocarbon-impacted marine environments. The aim of this preliminary study is to investigate the presence of oil-degrading bacteria in the mussel Mytilus galloprovincialis during growth in polluted ecosystems. All the experiments were carried out in a mesocosm system designed to simulate chronic pollution and to enable direct exposure of mussels to chemicals. Quantitative (4′,6-diamidino-2-phenylindole, colony-forming units, Most Probable Number) analyses and screening (presence/absence) of metabolic functional genes were performed to analyse bacterial populations inside the gills of mussels exposed and not exposed to hydrocarbons. The data obtained show that the presence of hydrocarbons affected the abundance of bacteria inside the gills of specimens and determines selection for specific (hydrocarbon-degrading) bacteria (i.e. Alcanivorax sp. and Marinobacter sp.). However, is not yet clear whether the presence of such genera of bacteria inside the mussel is due to symbiosis or as a result of filtration.     

Intra-sexual variability in feeding behaviour of a mountain ungulate: size matters

Many studies comparing the behaviour of individuals of different genders or species showed that animal body mass and forage quality/quantity are key elements of the foraging ecology of herbivores. Since body mass could also influence the animal’s sensitivity to predation risk, its vigilance behaviour should consequently be affected. Alpine ibex (Capra ibex) is characterised by a strong dimorphism among males of different ages, thus representing an ideal case study for testing the Jarman-Bell principle, avoiding possibly misleading effects resulting from the comparison between different species or genders. We analysed the fine-scale foraging behaviour of male ibex in order to assess the effect of body mass and the effects of vegetation quality/quantity on both foraging and vigilance behaviour. Our results showed that smaller males were more selective than larger ones, on account of their lower capability of digesting plant. Smaller males scanned the environment more frequently than larger ones. Male ibex grazed more selectively in sites with high quality forage and their bite rate increased as forage biomass decreased. Vigilance frequency increased with increasing forage biomass as, under these circumstances, ibex are able to prolong anti-predator vigilance while chewing bites that have already been cropped. Our findings highlight the effects of body mass per se on both foraging and anti-predator behaviours in herbivores, thus supporting the Jarman-Bell principle. Foraging can arguably be considered a very flexible behaviour with high evolutionary relevance as it enables herbivores to optimally adjust their total energy intake under varying conditions of food resources.