Description and microhabitat characterization of the third stage larvae of Pseudoterranova cattani George-Nascimento and Urrutia, 2000 (Ascaridoidea: Anisakidae) from the red searobin Prionotus nudigula (Scorpaeniformes: Triglidae) off Patagonia, Argentin

HERNANDEZ-ORTS JESÚS SERVANDO; AZNAR FRANCISCO J.; BLANCO-COSTA ISABEL; GARCÍA NÉSTOR ANÍBAL; VILLORA-MONTERO MARIA; CRESPO ENRIQUE ALBERTO; RAGA JUAN ANTONIO; MONTERO FRANCISCO E.

PARASITES AND VECTORS

BIOMED CENTRAL LTD

Lugar: Londres; Año: 2013 vol. 6 p. 1 - 15

1756-3305

AbstractBackground: Third-stage larvae of the Pseudoterranova decipiens species complex (also known as sealworms) havebeen reported in at least 40 marine fish species belonging to 21 families and 10 orders along the South Americancoast. Sealworms are a cause for concern because they can infect humans who consume raw or undercooked fish.However, despite their economic and zoonotic importance, morphological and molecular characterization ofspecies of Pseudoterranova in South America is still scarce.Methods: A total of 542 individual fish from 20 species from the Patagonian coast of Argentina were examined forsealworms. The body cavity, the muscles, internal organs, and the mesenteries were examined to detectnematodes. Sealworm larvae were removed from their capsules and fixed in 70% ethanol. For molecularidentification, partial fragments of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) were amplified for10 isolates from 4 fish species. Morphological and morphometric data of sealworms were also obtained.Results: A total of 635 larvae were collected from 12 fish species. The most infected fish was Prionotus nudigula,followed by Percophis brasiliensis, Acanthistius patachonicus, Paralichthys isosceles, and Pseudopercis semifasciata.Sequences obtained for the cox1 of sealworms from A. patachonicus, P. isosceles, P. brasiliensis and P. nudigulaformed a reciprocally monophyletic lineage with published sequences of adult specimens of Pseudoterranovacattani from the South American sea lion Otaria flavescens, and distinct from the remaining 5 species ofPseudoterranova. A morphological description, including drawings and scanning electron microscopyphotomicrographs of these larvae is provided. Sealworms collected from Argentinean fishes did not differ in theirdiagnostic traits from the previously described larvae of P. cattani. However a discriminant analysis suggests thatspecimens from P. nudigula were significantly larger than those from other fishes. Most of the sealworms werecollected encapsulated from the muscles and, to a lesser degree, from the mesenteries and the liver.Conclusions: We provided the first molecular identification, morphological description and microhabitatcharacterization of sealworm larvae from the Argentinean Patagonian coast. We also reported the infection levels ofsealworms on 20 fish species in order to elucidate the life cycle of these nematodes in this area.