Acta Parasitologica, Vol. 51, No. 1, 2006, 47-50 Lia I. Lunaschi* and Fabiana B. Drago - Description of a new species of Dolichorchis (Digenea,
Diplostomidae) in the cocoi heron, Ardea cocoi (Aves, Ardeidae), from Argentina
Division Zoologia Invertebrados, Museo de La Plata, Paseo del Bosque S/N, 1900 La Plata, Buenos Aires, Argentina
*Corresponding author: lunaschi@museo.fcnym.unlp.edu.ar
ABSTRACT
Dolichorchis lacombeensis sp. nov., a digenean parasite of the gut of the cocoi heron, Ardea cocoi (L.), is described as a new
species from Buenos Aires Province, Argentina. This new species most closely resembles D. buteii and D. tregenna in the distribution
of the vitelline follicles, which reach the intestinal bifurcation in the forebody. D. buteii can be distinguished from
D. lacombeensis sp. nov. by the distribution of the vitelline follicles in the hindbody, which are concentrated in midline, by the
presence of a sphincter in genital pore and by the size of holdfast organ and posterior testis, which are larger, (240-400 ×
176-240 and 315-464 × 240-410 um, respectively). D. tregenna differ from the new species by their larger measurements
(pseudosuckers' length 90-100, pharynx 52-90 × 50-70 and eggs 89-104 × 48-68 um).
KEY WORDS: Dolichorchis lacombeensis sp. nov., Digenea, Diplostomidae, Ardea cocoi, birds, Argentina