Molecular and morphological characterization of Austrodiplostomum ostrowskiae Dronen, 2009 (Digenea: Diplostomatidae), a parasite of cormorants in the Americas
Por:
Garcia-Varela, M., Sereno-Uribe, A. L., Pinacho-Pinacho, C. D., Dominguez-Dominguez, O., Perez-Ponce de Leon, G.
Publicada:
1 mar 2016
Resumen:
The diplostomid genus Austrodiplostomum currently contains two species,
i.e. A. mordax and A. ostrowskiae. Adults of these species inhabit the
intestine of cormorants of the genus Nannopterum, whereas larval forms
(metacercariae) are found in the eyes (vitreous humor) of freshwater
fishes. Records of both species have been established across a wide
geographic range in the Americas. Diplostomid adults and metacercariae
were collected from a wide geographical range that spans from
south-eastern Mexico, southwards to Central and South America. Even
though the diplostomid has been largely reported in Mexico as
Diplostomum (Austrodiplostomum) compactum, our specimens were identified
morphologically as A. ostrowskiae. Sequences of the mitochondrial gene
cytochrome c oxidase (cox 1) were obtained for 86 individuals, including
15 adults recovered from the intestine of Nannopterum brasilianus, in
five localities, and 71 metacercariae from the eyes of ten fish species,
in 13 localities. Sequences were used to evaluate the genetic diversity,
and to test conspecificity of these specimens with the available
sequence of A. ostrowskiae. Sequences were aligned with another 12 taxa
representing five genera of Diplostomatidae, forming a dataset of 104
taxa with 478 nucleotides. The genetic divergence estimated among the 86
sequenced individuals, and that of A. ostrowskiae from the
double-crested cormorant, Nannopterum auritus, in the USA, was very low,
ranging from 0 to 0.8%. The maximum likelihood (ML) and Bayesian
consensus trees showed that all sequences nested within a monophyletic
lineage, with strong bootstrap and Bayesian posterior probability
support values (100/1.0). In conclusion, a link between the
metacercariae in fish and the adults in cormorants was established,
indicating also that a single species is found in the distribution range
comprising southern USA, southwards to Venezuela. Previous records of
this species, particularly from Mexico, need to be corrected.
Filiaciones:
Garcia-Varela, M.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ave Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
Sereno-Uribe, A. L.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ave Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
Pinacho-Pinacho, C. D.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ave Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
Dominguez-Dominguez, O.:
Univ Michoacana, Fac Biol, Lab Biol Acuat, Morelia, Michoacan, Mexico
Perez-Ponce de Leon, G.:
Univ Nacl Autonoma Mexico, Inst Biol, Dept Zool, Ave Univ 3000,Ciudad Univ, Mexico City 04510, DF, Mexico
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