http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sun, 26 May 2013 05:46:30 GMT 2013-05-26T05:46:30Z http://hdl.handle.net/2067/684 Title: Sistematica molecolare e coevoluzione parassita-ospite in specie del genere Contracaecum (Nematoda : Anisakidae), parassite di uccelli ittiofagi Authors: Paoletti, Michela Abstract: I nematodi del genere Contracaecum sono parassiti allo stadio adulto di uccelli ittiofagi e allo stadio larvale di pesci. Il presente lavoro ha avuto lo scopo di studiare la variazione genetica di popolazioni adulte e larvali di Contracaecum campionate rispettivamente in diverse specie di uccelli ittiofagi (appartenenti alle famiglie Pelecanidae, Phalacrocoracidae, Ardeidae, Alcidae e Spheniscidae) e pesci, provenienti da diverse località; lo studio è stato effettuato mediante l’utilizzo di due tipi di marcatori molecolari, uno nucleare (20 loci enzimatici) e l’altro mitocondriale (sequenze del gene della cox-2, 519 paia di basi). La caratterizzazione genetica degli esemplari saggiati ha permesso di identificare 12 specie appartenenti al genere Contracaecum; tra queste sono state caratterizzate 3 specie gemelle appartenenti alla morfospecie C. multipapillatum (s.l.) (C. multipapillatum A, B e C) e 2 nuovi taxa, qui denominati C. bioccai e Contracaecum sp.. E’ stata inoltre riconosciuta la validità delle specie C. rudolphii A e B, C. septentrionale, C. microcephalum, C. micropapillatum, C. pelagicum e C. variegatum. Inoltre, l’dentificazione delle forme larvali a disposizione ha permesso di chiarire parte dei cicli biologici di alcune specie di Contracaecum qui studiate, anche in relazione alla biologia ed ecologia dell’ospite definitivo. L’applicazione di marcatori genetico-molecolari ha permesso, infine, di ipotizzare l’esistenza di parallelismi tra la filogenesi delle specie del genere Contracaecum e quella dei loro ospiti definitivi(uccelli ittiofagi), evidenziando possibili fenomeni di cospeciazione parassita-ospite.; Nematodes of genus Contracaecum are parasites of fish-eating birds and fishes, at adult and larval stage respectively. The aim of this study has been to analyze the genetic variation of Contracaecum adult and larval populations, sampled in several species of fish-eating birds (Pelecanidae, Phalacrocoracidae, Ardeidae, Alcidae and Spheniscidae) and fishes, coming from the whole world. The analyses were performed using two molecular markers, a nuclear one (20 enzyme loci) and a mitochondrial cox-2 gene (sequences, 519 bp). The genetic survey has allowed identifying 12 species belonging to the genus Contracaecum, including 3 sibling species belonging to C. multipapillatum (s.l.) complex and 2 new taxa, here named C. bioccai and Contracaecum sp.. Also, it has been recognized the validity as biological species of C. rudolphii A and B, C. septentrionale, C. microcephalum, C. micropapillatum, C. pelagicum and C. variegatum. Moreover, the larval identification has concurred to clarify partially the life-cycle of some Contracaecum species, and the relationships with the definitive host biology and ecology. Finally, molecular markers analyses evidenced some parallelisms between phylogenies of Contracaecum species and those of their definitive hosts (fish-eating birds), emphasizing possible parasite-host co-speciation. Description: Dottorato di ricerca in Ecologia e gestione delle risorse biologiche Tue, 23 Jun 2009 22:00:00 GMT http://hdl.handle.net/2067/684 2009-06-23T22:00:00Z http://hdl.handle.net/2067/1794 Title: Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes Authors: Colón-Llavina, Marlene M.; Mignucci-Giannoni, Antonio A.; Mattiucci, Simonetta; Paoletti, Michela; Nascetti, Giuseppe; Williams Jr., Ernest H. Abstract: Studies of marine mammal parasites in the Caribbean are scarce. An assessment for marine mammal endo- and ectoparasites from Puerto Rico and the Virgin Islands, but extending to other areas of the Caribbean, was conducted between 1989 and 1994. The present study complements the latter and enhances identification of anisakid nematodes using molecular markers. Parasites were collected from 59 carcasses of stranded cetaceans and manatees from 1994 to 2006, including Globicephala macrorhynchus, Kogia breviceps, Kogia sima, Lagenodelphis hosei, Mesoplodon densirostris, Peponocephala electra, Stenella longirostris, Steno bredanensis, Trichechus manatus. Tursiops truncatus, and Ziphius cavirostris. Sixteen species of endoparasitic helminthes were morphologically identified, including two species of acanthocephalans (Bolbosoma capitatum, Bolbosoma vasculosum), nine species of nematodes (Anisakis sp., Anisakis brevispiculata, Anisakis paggiae, Anisakis simplex, Anisakis typica, Anisakis ziphidarium, Crassicauda anthonyi, Heterocheilus tunicatus, Pseudoterranova ceticola), two species of cestodes (Monorygma grimaldi, Phyllobothrium delphini), and three species of trematodes (Chiorchis groschafti, Pulmonicola cochleotrema, Monoligerum blairi). The nematodes belonging to the genus Anisakis recovered in some stranded animals were genetically identified to species level based on their sequence analysis of mitochondrial DNA (629 bp of mtDNA cox 2). A total of five new host records and six new geographic records are presented. Description: L'articolo è disponibile sul sito dell'editore http://www.springerlink.com/ Wed, 31 Dec 2008 23:00:00 GMT http://hdl.handle.net/2067/1794 2008-12-31T23:00:00Z http://hdl.handle.net/2067/1793 Title: Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: the importance of host's ontogeny Authors: Santoro, Mario; Badillo, Francisco J.; Mattiucci, Simonetta; Nascetti, Giuseppe; Bentivegna, Flegra; Isacco, Gianni; Travaglini, Andrea; Paoletti, Michela; Kinsella, John M.; Tomas, Jesus; Raga, Juan A.; Aznar, Francisco J. Abstract: We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compatible with the hypothesis that parasite communities reflect the ontogenetic shift that juvenile loggerheads undergo from oceanic to neritic habitats. The smallest turtles at the putative oceanic, pelagic-feeding stage harboured only the 2 digenean species that were regionally the most frequent, i.e. Enodiotrema megachondrus and Calycodes anthos; the largest turtles at the putative neritic, bottom-feeding stage harboured 11 helminth taxa, including 3 nematode species that were rare or absent in turtles that fed partially on pelagic prey. Mean species richness per host was low (range: 1.60–1.89) and did not differ between localities. Variance ratio tests indicated independent colonization of each helminth species. Both features are expected in ectothermic and vagrant hosts living in the marine environment. Description: L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2067/1793 2009-12-31T23:00:00Z