A new species of Hysterothylacium (Ascaridoidea, Anisakidae) parasitic in Zenopsis conchifer (Zeiformes, Zeidae) from Argentinean waters

ROSSIN M. ALEJANDRA; LUCIANA L. DATRI; INÉS S. INCORVAIA; JUAN T. TIMI

ACTA PARASITOLOGICA

VERSITA

Año: 2011 p. 310 - 314

1230-2821

A new species of parasitic nematode, Hysterothylacium spirale sp. nov. (Ascaridoidea, Anisakidae), is described based on specimenscollected from the intestine and pyloric caeca of the silvery john dory Zenopsis conchifer (Lowe) (Zeiformes, Zeidae),from the Argentinean Shelf (35°05΄-40°46΄S, 53°03΄-58°07΄W). Among the 66 valid species described so far in the genus, thenew species most closely resembles H. zenis (Baylis, 1929). Both species, apparently specific for fishes of the family Zeidae,share the shape of the dorsal lip, the long expanded lateral alae originating from subventral interlabia and the ornamentation ofthe tail tip, as well as general morphometry. The combination of these shared features distinguishes both species from all congenersso far known. However, the new species is distinguishable from H. zenis by having shorter interlabia, and consequentlythe lateral alae originating more posteriorly, shorter spicules, a smaller number of postcloacal papillae and the presence of twopairs of double postcloacal papillae.