RESUMO
A new species, Stephanoprora aylacostoma is described and its life cycle was resolved experimentally. The prosobranch snail Aylacostoma chloroticum Hylton Scott, collected in the Yacyretá dam, Province of Misiones, Argentina, was found naturally infected with large-tailed cercariae possessing a prepharyngeal body and corpuscles in the excretory system but lacking collar spines. Metacercariae, which encysted on the gills of experimentally infected fishes Cnesterodon decemmaculatus (Jenyns) and Poecilia reticulata (Peters) (Poecilidae), developed collar spines after 10 days. Tetragonopterid fishes Moenckhausia dichroura (Kner), Astyanax erythropterus (Holmberg) and Hyphesobrycon serpae (Durbin in Eigenmann) were found infected naturally. Sexually mature adults were recovered from domestic chicks at day 7 post-exposure. Eggs shed in chick faeces developed to miracidia within 13-15 days; sporocysts were found on the gills of snails. The new species differs from other species of the genus in its larger eggs, in the smaller, slender body and smaller collar spines of the adult and in the morphological and biological features of the larval stages.
Assuntos
Galinhas/parasitologia , Echinostomatidae/crescimento & desenvolvimento , Peixes/parasitologia , Interações Hospedeiro-Parasita , Estágios do Ciclo de Vida , Caramujos/parasitologia , Animais , Argentina , Echinostomatidae/anatomia & histologia , Echinostomatidae/classificação , Echinostomatidae/fisiologia , Fezes/parasitologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Contagem de Ovos de Parasitas , Doenças das Aves Domésticas/parasitologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/veterináriaRESUMO
Biomphalaria peregrina was found to be naturally infected with cercariae of Zygocotyle lunata in a pond of the Zoological Garden of Buenos Aires. Mice and chicks were fed metacercariae and gravid adults recovered. Eggs recovered from mice feces were used for experimental infections. Laboratory-reared B. peregrina and 4 other Biomphaluria spp. were successfully infected with Z. lunata miracidia. Biomphaleria glabrata was refractory. Species of Helisoma, the only intermediate hosts of Z. lunata so far reported, have never been found in Argentina. Species of Biomphalaria may be intermediate hosts of Z lunata in the southern region of the Parana River Basin.
Assuntos
Biomphalaria/parasitologia , Doenças das Aves/transmissão , Vetores de Doenças , Paramphistomatidae/fisiologia , Infecções por Trematódeos/veterinária , Animais , Argentina , Doenças das Aves/parasitologia , Aves , Galinhas , Camundongos , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/transmissãoRESUMO
Two species of Digenea are recorded from the intestine of Percichthys trucha (Percichthydae) from Patagonian water bodies. Polylekithum percai n. sp. (Allocreadiidae) is distinguished by its body size, the relative size of the suckers, the anterior extension of the vitelline fields, the number of eggs in the uterus and the different species of fish host from the two previously described species of Polylekithum. Homalometron (= Austrocreadium) papilliferum (Szidat, 1956) n. comb. is redescribed. Due to its spined tegument and the absence of a cirrus-sac, this species is considered a member of the family Apocreadiidae.
Assuntos
Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Argentina , Trematódeos/anatomia & histologia , Infecções por Trematódeos/parasitologiaRESUMO
Steganoderma szidati n. sp. is described from the intestine of two freshwater fishes, Galaxias maculatus and G. platei (Galaxiidae), from Andean lakes in Patagonia, Argentina. This freshwater zoogonid species fits in the genus Steganoderma (sensu Bray, 1987) because of the length of the caeca and the position of the vitelline follicles. The new species is characterised by possessing 6-13 vitelline follicles situated between the anterior margin of the ventral sucker and the posterior margin of the testis. The gonads are in the anterior hindbody and the ovary is anterior to the right testis. The cirrus has two conspicuous spines at its distal end, and the seminal vesicle always exhibits a constriction. The excretory vesicle never reaches the level of the posterior margin of the testes.
Assuntos
Peixes/parasitologia , Trematódeos/classificação , Animais , Argentina , Água Doce , Intestinos/parasitologia , Trematódeos/anatomia & histologiaRESUMO
The life cycle of Pygidiopsis crassus n. sp. was experimentally reproduced, starting from cercariae from naturally infected Littoridina parchappei collected from Lujan River and different ponds in Buenos Aires Province, Argentina. Metacercariae were found encysted in the body cavity of experimentally and naturally infected fishes Cnesterodon decemmaculatus and naturally infected Jenynsia lineata. Adults were obtained experimentally in chicks and mice. The natural host is unknown. The new species is compared with Pygidiopsis macrostomum Travassos 1928, from Rattus norvegicus and from Noctilio leporinus mastivus, differing in body and egg sizes, in the size relation of oral and ventral sucker and the shape of excretory vesicle.
Assuntos
Peixes/parasitologia , Heterophyidae/crescimento & desenvolvimento , Animais , Argentina , Interações Hospedeiro-Parasita , Camundongos , RatosRESUMO
The characteristics of the population dynamics of Posthodiplostomum nanum have been studied in two of its intermediate hosts, using prevalence, intensity and maturity of the metacercariae, considering the influence of the water temperature. In addition to this some ecological implications are described. There were made 18 samples monthly or bimonthly from may 1986 until march 1989, 1113 fishes were captured out of which 956 metacercariae were obtained. P. nanum was present along the year, having significant seasonal variation in prevalence and intensity of infestation. It was observed that the water temperature is a relevant factor in the maturation of the parasite. The values of the prevalence and intensity of infestation were higher in Jenynsia lineata than in Cnesterodon decemmaculatus. This could be explained by various factors: a) distribution of the first intermediate host; b) behavior of the second intermediate host and c) individual physiological differences of each host, specially in relation to reproduction. The relation S2/X fluctuated during the whole year, indicating the recruitment-period (autumn, spring) and the nonrecruitment-period (winter, summer) of metacercariae.
Assuntos
Peixes/parasitologia , Trematódeos/fisiologia , Animais , Argentina , Distribuição de Qui-Quadrado , Feminino , Água Doce , Masculino , Dinâmica Populacional , Estações do AnoRESUMO
The life cycle of Ascocotyle (Leighia) hadra n. sp. was experimentally reproduced, starting from cercariae from naturally infected Littoridina parchappei, collected from Los Ranchos stream, near Mercedes city, Buenos Aires Province, Argentina. Metacercariae were found encysted in the liver and mesentery of experimentally and naturally infected fishes Cnesterodon decemmaculatus and Jenynsia lineata. Adults were obtained experimentally in chicks and mice. The natural host is unknown. The new species is compared with Ascocotyle (Leighia) mcintoshi Price 1936 as described by Leigh, 1974, differing in behavior and morphology of cercarial, metacercarial and adult stages.
Assuntos
Doenças dos Peixes/parasitologia , Peixes/parasitologia , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/veterinária , Animais , Argentina , Galinhas/parasitologia , Feminino , Larva , Masculino , Camundongos , Caramujos/parasitologia , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/classificação , Trematódeos/isolamento & purificação , Infecções por Trematódeos/parasitologiaRESUMO
In overflowed areas from the Lujan-River near Zelaya, province of Buenos Aires, Argentina, a xiphidiocercaria with stenostome excretory system and 2 [(4 + 4 + 4) + (4 + 4 + 4 +)] = 48 flame cells was found in Ampullaria canaliculata. The cercaria encyst experimentally in the skin and internal organs of tadpoles. Natural infections were found in Hyla pulchella. The metacercaria, excepting the excretory system, is similar to Travtrema stenocotyle Cohn, 1902 from snakes.--In Leimadophis poecilogyrus 4 Trematode specimens were found and provisionally classified as Travtrema stenocotyle. A revision of the excretory system of Travtrema stenocotyle is suggested.
Assuntos
Moluscos/parasitologia , Trematódeos/anatomia & histologia , Animais , Argentina , Ecologia , Trematódeos/classificação , Trematódeos/crescimento & desenvolvimentoRESUMO
With metacercariae encysted naturally in the visceral cavity of Megadytes glauca-larvae (Dityscidae), day old unfed chicken and a Belonopterus cayennensis were infected and adults of Stomylotrema vicarium Braun, 1901 obtained. Metacercariae and adults have an excretory bladder with lateral ramifications and 4 groups of 10, exceptionally 12 flame cells on each body side. Very young metacercariae without cysts presented a big stylet. A corresponding virgula-cercaria in Ampullaria canaliculata is supposed.