Journal ArticleDOI
Genetic and ecological data on the Anisakis simplex complex, with evidence for a new species (Nematoda, Ascaridoidea, Anisakidae).
Simonetta Mattiucci,Giuseppe Nascetti,R Clanchi,Lia Paggi,Paola Arduino,L Margolis,J. Brattey,Stephen C. Webb,Stefano D'Amelio,P. Orecchia,Luciano Bullini +10 more
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TLDR
A new distinct gene pool was detected, showing different alleles with respect to A. simplex sensu stricto and Anisakis pegreffii, widely extending the geographic ranges and the number of hosts of these 2 species.Abstract:
Isozyme analysis at 24 loci was carried out on anisakid nematodes of the Anisakis simplex complex, recovered from various intermediate/paratenic (squid, fish) and definitive (marine mammals) hosts from various parts of the world. A number of samples were found to belong to A. simplex sensu stricto and Anisakis pegreffii, widely extending the geographic ranges and the number of hosts of these 2 species. In addition, a new distinct gene pool was detected, showing different alleles with respect to A. simplex s. str and A. pegreffii at 5 diagnostic loci (99% level). Samples with this gene pool were assigned to a new species, provisionally labeled A. simplex C. Reproductive isolation between A. simplex C and the other 2 Anisakis species was directly assessed by the lack of hybrid and recombinant genotypes in mixed samples from sympatric areas, i.e., Pacific Canada for A. simplex C+A. simplex s. str., South Africa and New Zealand for A. simplex C+A. pegreffii, even when such samples were recovered from the same individual host. Similar levels of genetic divergence were observed among the three species (DNei from 0.36 to 0.45). At the intraspecific level, Canadian Pacific and Austral populations of A. simplex C were found to be genetically rather differentiated from one another (average DNei = 0.08), contrasting with the remarkable genetic homogeneity detected within both A. simplex s. str. and A. pegreffii (average DNei about 0.01). Accordingly, a lower amount of gene flow was estimated within A. simplex C (Nm = 1.6) than within the other 2 species (Nm = 5.4 and 17.7, respectively). Anisakis simplex C showed the highest average values of genetic variability with respect to both A. simplex s. str. and A. pegreffii, e.g., expected mean heterozygosity. Hr = 0.23, 0.16, and 0.11, respectively, in the 3 species. Data on geographic distribution and hosts of the 3 members so far detected in the A. simplex complex are given. Their ecological niche is markedly differentiated, with a low proportion of hosts shared. Intermediate and definitive hosts of A. simplex s. str. and A. pegreffii appear to belong to distinct food webs, benthodemersal, and pelagic, respectively; this would lead to different transmission pathways for the parasites.read more
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Journal ArticleDOI
Fish-borne parasitic zoonoses: Status and issues
TL;DR: Emphasis has been placed on liver fluke diseases such as clonorchiasis, opisthorchiasis and metorChiasis, as well as on intestinal trematodiasis (the heterophyids and echinostomes), anisakiasis (due to Anisakis simplex larvae), and diphyllobothriasis.
Book ChapterDOI
Advances and trends in the molecular systematics of anisakid nematodes, with implications for their evolutionary ecology and host-parasite co-evolutionary processes.
TL;DR: Examples in which anisakid nematodes recognized genetically at the species level in definitive and intermediate/paratenic hosts from various geographical areas of the Boreal and Austral regions and their infection levels have been used as biological indicators of fish stocks and food-web integrity in areas at high versus low levels of habitat disturbance are presented.
Journal ArticleDOI
Genetic markers in ribosomal DNA for the identification of members of the genus Anisakis (Nematoda: ascaridoidea) defined by polymerase-chain-reaction-based restriction fragment length polymorphism.
Stefano D'Amelio,Kostas D. Mathiopoulos,Cláudia Portes Santos,O.N Pugachev,S.C. Webb,M Picanço,Lia Paggi +6 more
TL;DR: The polymorphisms obtained by restriction fragment length polymorphisms have provided a new set of genetic markers for the accurate identification of sibling species and morphospecies.
Journal ArticleDOI
Molecular systematics, phylogeny and ecology of anisakid nematodes of the genus Anisakis dujardin, 1845 : An update
TL;DR: Preliminary data for reconstruction of a possible co-evolutionary scenario between cetacean hosts and their Anisakis endoparasites suggests that cospeciation and host-switching events may have accompanied the evolution of this group of parasites.
Journal ArticleDOI
Post-mortem findings in harbour porpoises (phocoena phocoena) from the German North and Baltic Seas
TL;DR: Bacteriological examination suggested that pneumonia was mainly caused by secondary bacterial infection and not by parasitic infestation alone, and Beta-haemolytic streptococci were considered to be the main infectious agents.