CONTRACAECUM AUSTRALE N. SP. (NEMATODA: ANISAKIDAE) IN PHALACROCORAX BRASILIANUS (GMELIN) (PHALACROCORACIDAE) FROM OFF CHILE COAST: MOLECULAR AND MORPHOLOGICAL CHARACTERS

LUCAS GARBIN; SIMONETTA MATTIUCCI; MICHELA PAOLETTI; D. GONZALEZ ACUÑA; GIUSEPPE NASCETTI

JOURNAL OF PARASITOLOGY

Allen Press

Año: 2009

0022-3395

ABSTRACT: Contracaecum australe n. sp. is described from the Neotropical cormorant,Phalacrocorax brasilianus (Gmelin) in Chile, based on morphology and mtDNA cox-2sequence analysis (519bp). Moreover, genetic relationships between the new taxon and therelated congeners from fish-eating birds, previously characterized genetically on the samegenetic marker (i.e. C. rudolphii A and C. rudolphii B of Bullini et al., (1986), C.septentrionale Kreis, 1955, C. microcephalum (Rudolphii, 1809), C. bioccai Mattiucci etal., 2008, C. pelagicum Johston and Mawson, 1942, C. micropapillatum (Stossich, 1890),C. gibsoni Mattiucci et al., 2010 and C. overstreeti Mattiucci et al., 2010) are presented asinferred from mtDNA cox-2 analysis. The MP, NJ and ML trees were congruent indepicting C. australe n. sp. as forming a distinct clade, highly supported, from the otherContracaecum spp., thus it validates its specific status. Phylogenetic tree inferred from ML,highly supports C. australe n. sp. as a sister taxon to the previously detected species fromcormorants of the Boreal hemisphere (i.e. C. rudolphii A, C. rudolphii B and C.septentrionale). Morphological analysis and the differential diagnosis of male specimensenabled the detection of differences in a number of characters, including spicule length, thepeculiar construction in male tail, male spicule length. According to the genetic andmorphological results obtained, the erection of a new taxon from fish-eating birds of theAustral region is given and its formal description is presented. The findings of C. australen. sp., a parasite of a cormorant, as forming a supported clade with the other species ofContracaecum parasites of other Phalacrocorax spp. which, on the other hand, are forminga well supported clade in a phylogenetic analysis suggested for seabird species, appear tosupport a host-parasite association between the C. rudolphii A, C. rudolphii B, C.septentrionale and C. australe n. sp. and the fish-eating birds of the familyPhalacrocoracidae.