The present results dealing with the antiphytoviral activity of essential oil indicate that these plant metabolites can trigger a response to viral infection. The essential oil from Micromeria croatica and the main oil components β-caryophyllene and caryophyllene oxide were tested for antiphytoviral activity on plants infected with satellite RNA associated cucumber mosaic virus. Simultaneous inoculation of virus with essential oil or with the dominant components of oil, and the treatment of plants prior to virus inoculation, resulted in a reduction of virus infection in the local and systemic host plants. Treatment with essential oil changed the level of alternative oxidase gene expression in infected Arabidopsis plants indicating a connection between the essential oil treatment, aox gene expression and the development of viral infection.

The diet and feeding strategy of thornback ray Raja clavata, from the eastern-central Adriatic Sea, were investigated. Stomach contents of 428 specimens, total length (L(T)) of 14·0-75·1 cm, were collected from commercial bottom trawls. The prey items identified in the stomachs belong to eight major groups: Cephalopoda, Polychaeta, Stomatopoda, Decapoda (Natantia and Reptantia), Mysidacea, Isopoda, Amphipoda and Teleostei. Decapods were the most important prey (index of relative important, %I(RI) ,= 72·8) followed by teleosts (%I(RI) = 20·4), whereas other prey groups were only occasionally ingested. Small-sized individuals (<25 cm L(T)) fed primarily on small crustaceans (mysids and amphipods), whereas large-sized specimens consumed larger prey, such as decapods, cephalopods and teleosts. Diet composition showed little seasonal variation; decapods were the most important prey in all seasons. There was high dietary similarity between sampling locations. The percentage of empty stomachs did not differ significantly among size classes and seasons. In terms of composition by species, the diet of R. clavata was characterized by a variety of rare or unimportant prey. As a result, R. clavata could be considered a generalist predator.

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The feeding habits of small-spotted catshark, Scyliorhinus canicula, from the central Adriatic Sea, were investigated with respect to fish size, season and sampling location. Stomach contents of 1200 specimens, collected at monthly intervals (January to December 2010), were analysed. The prey items identified in the stomachs belonged to eight major groups: Cephalopoda, Polychaeta, Stomatopoda, Decapoda, Mysidacea, Euphausiacea, Amphipoda and Teleostei. Decapods were the most important ingested prey in all seasons, for medium sized fish (22Á38 cm TL). Euphausiids and mysids constituted the main prey items of small fish (B22 cm TL) while teleosts dominated the stomach contents of larger specimens (38 cm TL). Two decapods, Alpheus glaber (%IRI 0 5.1) and Solenocera membranacea (%IRI 0 3.0), were the most numerous prey items identified to species level. The mean weight of stomach contents (relative to predator size) increased significantly for fish larger than 30 cm TL, while the mean number of prey items did not differ significantly among size-classes. The percentage of empty stomachs showed a monthly variation with a maximal occurrence in February (48.0%) and a minimal in August (9.0%). The lowest feeding frequency could be related to low sea temperatures during the winter. The smallspotted catshark could be considered a generalistic predator.

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