MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
The development from metacercaria to adult of Gymnophallus australis Szidat, 1962 (Digenea: Gymnophallidae) from Patagonian coast (Argentina), with an emended diagnosis of the genus Gymnophallus Odhner, 1905
CREMONTE, F.; VAZQUEZ, N.; ITUARTE, C.
Año: 2008 vol. 69 p. 23 - 23
Parvatrema australis (Szidat, 1962) was described based on larval stages found in specimens of the mussel Mytilus edulis from Buenos Aires province (Argentina). Despite hundreds of mussels were later examined by Szidat himself, this parasite was never found again until now. In the present study, larval stages including germinal sacs found in mytilids from Patagonian coast (Argentina) were identified as P. australis. Metacercariae were incubated at in physiological solution at 39º C for 18-20 hours; after this time, 80% of specimens had eggs. P. australis is redescribed on the basis on infective metacercariae and adults obtained in laboratory, and reassigned to the genus Gymnophallus Odhner, 1900. The generic diagnosis of Gymnophallus is here emended to include as diagnostic characters the presence or absence of lateral lips, disposition and form [C.I.1] of vitellaria (paired or not, compact or follicular, paired or not) and presence of pars prostatica (i.e., prostatic cells are not opening into the prostatic duct). The validity as diagnostic characers (presence of lateral lips in [C.I.2] the oral sucker, form of vitellaria and excretory vesicle, extent of uterus) at genus level within the family Gymnophallidae is discussed. It is proposed that main unambiguous characters that could successfully used to distinguish among genera include ovary position, presence of ventral pit, pars prostatica and caecal pockets.