Morphological studies of Ancyracanthopsis winegardi Wong Anderson, 1990 (Nematoda: Acuarioidea), and larval stages of acuariid nematodes parasitic in Larus dominicanus Lichtenstein (Aves: Laridae)from Argentina

CREMONTE, FLORENCIA; NAVONE, GRACIELA TERESA; JORGE ALEJANDRO ETCHEGOIN

Systematic Parasitology

Año: 2000 vol. 45 p. 135 - 140

Ancyracanthopsis winegardi Wong & Anderson, 1990 (Nematoda: Acuarioidea) is described from Larus dominicanus Lichtenstein (Aves: Laridae) on the Southwest Atlantic coast (38°42'S, 59°47'W). The main character used to distinguish species of Ancyracanthopsis is the morpho1ogy of the pti1ina. Thus, although the specimens described here have some differences in the morphology and size of the spicules and in the female genitalia, they were referred to A. winegardi because they have a very similar ptilina. This is the first record of a member of Ancyracanthopsis from larid birds and for A. winegardi in the Southwest Atlantic coast. We have also studied acuariid larvae found inhabiting the gizzard alongside adult specimens of A. winegardi. Among those larvae, two morphological groups were clearly distinguished. The first group was characterised by the absence of ptillna and the presence of spicular primordia and rectal cells (third-stage larvae). The second group could be distinguished by the presence of ptilina and partly-developed genitalia (fourth-stage larvae ). In order to identify the larvae, a Principal Component Ana1ysis was applied to morphometric data taken from the third-stage larvae. These results and the morphology of the partly- developed ptilina of the fourth-stage larvae indicated that the larval stages found in L. dominicanus appear to belong to Sciadiocara haematopodi, Cremonte, Navone & Etchegoin, 1999.