Helminth parasites of fish and shellfish from the Santa Gilla Lagoon in southern Sardinia, Italy.

An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brackish water lagoon in southern Sardinia (western Mediterranean), resulted in the identification of 69 helminth parasite taxa and/or species from 13 fish species (n= 515) and seven bivalve species (n= 2322) examined between September 2001 and July 2011. The list summarizes information on the helminth parasites harboured by fish and molluscs contained in the available literature. Digenea species (37), both adults and larvae, dominated the parasite fauna, whereas Cestoda were the least represented class (three species). Monogenea, Nematoda and Acanthocephala were present with 17, 6 and 6 species, respectively, which were mainly adults. The most widespread parasite species was the generalist Contracaecum rudolphii A (Nematoda). Other species, such as the Haploporidae and Ascocotyle (Phagicola) spp. 1 and 2 (Digenea), showed a high family specificity in Mugilidae. Importantly, the study recorded the occurrence of potential zoonotic agents, such as Heterophyes heterophyes, Ascocotyle (Phagicola) spp. and C. rudolphii A, the latter two reaching the highest indices of infection in the highly marketed fish grey mullet and sea bass, respectively. The highest parasite richness was detected in Dicentrarchus labrax, which harboured 17 helminth species, whereas the lowest value was observed in Atherina boyeri, infected by only three species. The list includes the first geographical record in Italian coastal waters of Robinia aurata and Stictodora sawakinensis, and 30 reports of new host-parasite complexes, including the larval stages of Ascocotyle (Ascocotyle) sp. and Southwellina hispida in D. labrax.

Distribution and abundance of Bluetongue vectors in Sardinia: comparison of field data with prediction maps.

Following the spread of Bluetongue virus (BTV) in many Mediterranean countries during the last 5 years, presence of the main BTV vector, Culicoides imicola Kieffer (Diptera: Ceratopogonidae), was recorded in the region, including the island of Sardinia where the first BT epidemic originally started in the year 2000. Several models were also designed based on climate variables and satellite imaging in order to predict the presence and abundance of BTV vectors across Europe. A 3 years entomological survey (2001-2003) was conducted in the southern part of Sardinia confirming the widespread presence of C. imicola. However, substantial differences in terms of relative abundance were observed between field data and prediction maps based on satellite-derived climate variables. Distribution of other potential BT vectors, belonging to Culicoides obsoletus Meigen and Culicoides pulicaris Linnaeus groups was also not congruent with model-based predictions. These results stress the need of taking into account additional environmental factors (such as soil type, land usage, etc.) and local microclimatic conditions, especially related to breeding site requirements of Culicoides species, in order to predict the presence and abundance of BT vectors and to design reliable prediction maps on a local scale.

[Radiosensitivity curve of different stages of spermatogenesis of Anopheles atroparvus (Diptera:Nematocera)]. / Curva di radiosensibilita' degli stadi della spermatogenesi di Anopheles atroparvus (Diptera: nematocera)

In order to obtain a dose-hatchability curve for irradiated spermatogenetic stages of Anopheles atroparvus, we have irradiated with the same dose "4500 r" young fourth larval stages, old fourth larval stages, nymphae and adult males. Those different stages represent different phases of spermatogenesis. The peak of radiosensitivity for embryonic mortality, was found in spermatids, lowest appeared in spermatogonies.