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Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae)
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Orientador(es)
Resumo(s)
Genetic variation at 21 gene-enzyme systems was studied in a sample of an adult population of Anisakis typica
(Diesing, 1860) recovered in the dolphin Sotalia fluviatilis from the Atlantic coast of Brazil. The characteristic
alleles, detected in this population, made it possible to identify as A. typica, Anisakis larvae with a Type I morphol ogy (sensu Berland, 1961) from various fishes: Thunnus thynnus and Auxis thazard from Brazil waters, Trachurus
picturatus and Scomber japonicus from Madeiran waters, Scomberomorus commerson, Euthynnus affinis, Sarda
orientalis and Coryphaena hippurus from the Somali coast of the Indian Ocean, and Merluccius merluccius from
the Eastern Mediterranean. Characteristic allozymes are given for the identification, at any life-stage and in both
sexes, of A. typica and the other Anisakis species so far studied genetically. The distribution of A. typica in warmer
temperate and tropical waters is confirmed; the definitive hosts so far identified for this species belong to delphinids,
phocoenids and pontoporids. The present findings represent the first established records of intermediate/paratenic
hosts of A. typica and extend its range to Somali waters of the Indian Ocean and to the Eastern Mediterranean
Sea. A remarkable genetic homogeneity was observed in larval and adult samples of A. typica despite their
different geographical origin; interpopulation genetic distances were low, ranging from DNei = 0.004 (Eastern
Mediterranean versus Somali) to DNei = 0.010 (Brazilian versus Somali). Accordingly, indirect estimates of gene
flow gave a rather high average value of Nm = 6.00. Genetic divergence of A. typica was, on average, DNei = 1.12
from the members of the A. simplex complex (A. simplex s.s, A. pegreffii, A. simplex C) and DNei = 1.41 from
A. ziphidarum, which all share Type I larvae; higher values were found from both A. physeteris (DNei = 2.77) and A. brevispiculata (DNei = 2.52), which have Type II larvae (sensu Berland, 1961). Genetic relationships
among these species are shown using multidimensional scaling ordination (MDS). The genus Anisakis appears to
be phylogenetically heterogeneous and includes two distinct groups of species, which are morphologically and
genetically differentiated.
Descrição
Palavras-chave
Indian Ocean Atlantic coast Definitive host Indirect estimate Genetic homogeneity Anisakis typica Anisakis Dujardin . Faculdade de Ciências da Vida
Contexto Educativo
Citação
Mattiucci, S., Paggi, L., Nascetti, G. et al. Genetic markers in the study of Anisakis typica (Diesing, 1860): larval identification and genetic relationships with other species of Anisakis Dujardin, 1845 (Nematoda: Anisakidae). Syst Parasitol 51, 159–170 (2002). https://doi.org/10.1023/A:1014554900808
Editora
Kluwer Academic Publishers