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At least 19 recordsLinked to original sources
PubMed1983

[Sensillae of cercariae of Haplorchis taichui (Digenea, Heterophyidae). Discussion of the systematics of the Opisthorchioidea].

Cercarial chaetotaxy of Haplorchis taichui (Haplorchiinae, Heterophyidae) is described and compared to that of ten other Opisthorchioidea: three belonging to the Acanthostomidae (Acanthostominae), one to the Opisthorchiidae (Opisthorchiinae) and six to the Heterophyidae (among these, two Centrocestinae, two Apophallinae, one Euryhelminthinae and one Haplorchiinae). Cercarial chaetotaxy allow us to distinguish the considered species and genera, but does not support division of the Opisthorchioidea into families as these have been defined based on morphology of adults; it suggests that the Heterophyidae is heterogenous; it allows us to recognize the Opisthorchioidea characterized by a loss of hexaradial symmetry on the first cephalic cycle of sensillae and by the presence of two to five pairs of sensillae on a tail with proximal excretory apertures.

Animals↗
PubMed1982

[Sensillae and protonephridia of cercaria of Centrocestus formosanus and Centrocestus sp. (Centrocestinae, Heterophyidae)].

A description is given of cercarial chaetotaxy of two Centrocestinae (Heterophyidae, Opisthorchioidea) from Malaysia: Centrocestus formosanus and Centrocestus sp.--Comparison with cercarial chaetotaxy of taxonomically related groups indicates that 1. The chaetotaxy of the Centrocestinae agrees with that of other Opisthorchioidea, 2. There is an important difference between chaetotaxy of Centrocestinae and other Heterophyidae which suggest that the family is heterogeneous.

Animals↗
PubMed1992

Scanning electron microscopy of cercariae, metacercariae and adults of Pygidiopsis ardeae Køie, 1990 (Digenea, Heterophyidae).

The penetration apparatus of the cercaria of Pygidiopsis ardeae Køie, 1990 (Heterophyidae) is provided with five large preoral hooklets. Various types of presumably sensory structures surround the small oral aperture. Small, pointed spines protrude throughout the cercarial body. After parasite penetration and encystment in the fish intermediate host, the metacercarial tegument increases its absorptive area by developing irregular projections. Concurrently the pointed spines become scale-like and serrated. The tegumental outgrowths appear to have regressed in infective metacercariae. The external surface of mature worms removed from the intestine of domestic chickens does not differ from that of infective excysted metacercariae. Adults taken from experimentally infected chickens were identical to specimens obtained from naturally infected herons.

Animals↗
PubMed1981

Studies on trematodes of the family Heterophyidae (Odhner, 1914) in Iran: 1. Preliminary epidemiological surveys in man and carnivores in Khuzestan.

Trematodes of the family Heterophyidae in man and carnivores were studied in Khuzestan, south-west Iran. Eight hundred and eleven stool samples from a population of 3400 in 13 villages in a swampy area located in central Khuzestan were examined by the formalin-ether concentration technique. The following helminths were found: Ascaris lumbricoides 7%, Trichostrongylus spp. 53%, hookworms 4+, Trichuris trichiura 5%, Hymenolepis nana 12% and heterophyid spp. 8%. Post-mortem examination of carnivores revealed that 14.2% of jackals, 33.3% of foxes and 2.5% of dogs were infected with heterophyids, namely Metagonimus yokogawai, Heterophyes heterophyes and H. katsuradai. The freshwater snails Melanoides and Melanopsis spp. and brackish water fishes Barbus spp. and Mugil spp. were thought to be the intermediate hosts of these flukes in this area. This is the first report of heterophyid infection in man and carnivores in Iran.

Adolescent↗
PubMed1989

Identification of Stictodora lari (Heterophyidae) metacercariae encysted in the brackish water fish, Acanthogobius flavimanus.

Metacercariae of the genus Stictodora encysted in the head tissue of Acanthogobius flavimanus (the gobies) caught at Sachun-gun, Kyongnam Province, were identified to be Stictodora lari Yamaguti, 1939 (Trematoda: Heterophyidae), a new parasite fauna in Korea. The metacercariae were 0.39-0.43 mm by 0.32-0.35 mm in size, long elliptical, and with a thin and transparent cyst wall. Total 200 metacercariae were collected from 50 gobies. In order to obtain adult worms two kittens and a puppy were infected each with 34-100 metacercariae, and total 33 adults were recovered between the day 4 and day 8 post-infection. The S. lari adults measured 0.95-1.18 mm long and 0.26-0.32 mm wide and the eggs in uteri 0.028-0.033 mm by 0.017-0.020 mm. The most characteristic morphological feature of these flukes was the presence of a gonotyl and gonotyl spines arranged in two groups; densely crowded group of 30-40 spines and linearly-arranged one of 30-40 spines, together of which made a comma (or reversed comma) shape along the lateral margin of the gonotyl. It has been proved by this study that S. lari is distributed in southern coasts of Korea.

Animals↗
PubMed1992

Surface ultrastructure of Heterophyes nocens (Trematoda: Heterophyidae).

The surface ultrastructure of Heterophyes nocens (Trematoda: Heterophyidae) was studied by scanning electron microscopy(SEM). The adult worms were recovered from experimentally infected cats and from a naturally infected patient. They were leaf-like, ventrally concave, and ovoid or pyriform in shape. Ciliated knob-like sensory papillae (type I) were observed in single or grouped forms on and around the oral sucker, whereas non-ciliated round swellings (type II papillae) were seen on the lip of the ventral sucker. The tegumental spines around the oral sucker were 5-9 pointed, whereas those between the two suckers were 12-17 pointed. Ventrolaterally, three groups of 5-6 type I papillae were located between the oral and ventral suckers, with single ones alternating between them. The genital sucker was protruded or depressed, depending on the contraction state of the flukes, and the gonotyl spine number ranged 50-60. The number of tip points of tegumental spines was decreased posteriorly; finally they became 1-3 pointed. On the dorsal surface, 4 groups of 4-5 type I papillae were symmetrically located on both lateral sides, and the shape and distribution of tegumental spines were similar to those of the ventral surface. Although the tegumental ultrastructure of H. nocens was generally similar to those of other heterophyids, the genital sucker morphology including the number of gonotyl spines and/or the distribution pattern of tegumental spines and sensory papillae were suggested to be the characteristic features of H. nocens.

Animals↗
PubMed1994

The first discovery of an endemic focus of Heterophyes nocens (Heterophyidae) infection in Korea.

A highly endemic focus of human infection with Heterophyes nocens (Heterophyidae) was discovered from a small coastal village of Shinan-gun, Chollanam-do, for the first time in Korea. Fecal examinations by cellophane thick smear and formalin-ether sedimentation techniques revealed 42.9% heterophyid egg positive rate out of 98 inhabitants examined. It was difficult to confirm the species of heterophyids only by eggs. In order to collect the adult flukes, the egg positive cases were treated with 10 mg/kg single dose of praziquantel and purged with magnesium sulfate, and the adult worms were collected from the diarrheic stools. From each of 18 cooperative patients 1 to 1,124 (total 4,730) H. nocens worms were recovered, together with a few to large numbers of heterophyids (Pygidiopsis summa, Stictodora fuscatum) and/or gymnophallids (Gymnophalloides seoi). It is speculated that H. nocens might be widely distributed along the southwestern coastal areas where the brackish water fish such as the mullets or gobies are popularly eaten raw.

Adult↗
PubMedDate not supplied

Human parasitism by Phagicola sp (Trematoda, Heterophyidae) in Cananéia, São Paulo state, Brazil.

We report one case of parasitism by Phagicola sp. (Trematoda, Heterophyidae) in a 31 year-old woman who, in 1987, travelled and stayed several months in the municipality of Cananéia (SP), where she ingested, in various occasions, raw mullet (Mugil sp.). The patient referred mild intestinal pain and laboratory examinations showed eggs of Phagicola sp. in the stools and a slight increase in eosinophil blood levels (8%). After treatment with praziquantel (75 mg/kg per day for three days) all the symptoms and signs disappeared. This is, certainly, the first record of human infection by Phagicola sp. in Brazil and, perhaps, in countries other than the U.S.A. where unclear references to a few human cases were reported in the South-eastern region.

Adult↗
PubMed1990

The life cycle of Pygidiopsis ardeae Køie, 1990 (Digenea, Heterophyidae).

Ocellate cercariae, consistent with the description of Cercaria angularis Honer, 1961, developing in rediae in Hydrobia ulvae (Pennant) and Hydrobia ventrosa (Montagu) (Prosobranchia, Hydrobiidae) from Denmark, were shown to be larvae of Pygidiopsis ardeae Køie, 1990 (Heterophyidae, Pygidiopsinae). Euryhaline fishes such as the sticklebacks Gasterosteus aculeatus Linnaeus and Pungitius pungitius (Linnaeus), and the common goby Pomatoschistus microps (Krøyer) are second intermediate hosts in Danish inlets. These species and the flatfishes Platichthys flesus (Linnaeus) and Limanda limanda (Linnaeus) were laboratory infected. Cercariae penetrated the gills where some encysted, but most scattered throughout the body via efferent branchial arteries and the dorsal aorta to encyst mostly in the mesenteries, spleen, and on the surface of other viscera. Twelve-week-old (15 C) metacercariae fed to domestic chickens and pigeons developed to adults of P. ardeae in less than 4 days. Grey herons, Ardea cinerea Linnaeus, were naturally infected with P. ardeae, which was not found in gulls or cormorants from the same area and feeding on similar fishes.

Animals↗
PubMed1991

Behavioural responses of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae) to computer-controlled shadow sequences.

The cercariae of Cryptocotyle lingua have a brief but active life during which they do not feed. In order to maximize the probability of infection they must respond to a variety of host-related stimuli yet conserve their finite energy reserves by minimizing unnecessary muscular activity. In laboratory experiments, simulated shadows representing the passage of a fish host were found to increase population activity levels. Evidence was also found for a relationship between shadow duration and the duration of subsequent bursts of swimming activity. Adaptation to continuous shadowing was recorded, its onset and magnitude being dependent on both the frequency and duration of shadows delivered. As cercariae aged they became less responsive to shadow stimuli, especially those of short duration.

Animals↗
PubMed1992

The effects of age, temperature, light quantity and wavelength on the swimming behaviour of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae).

Laboratory experiments indicated that the active life-span of the cercariae of Cryptocotyle lingua was temperature-dependent. An increase in water temperature and population age both correlated with a tendency for the organisms to become decaudate. The larvae were strongly photoresponsive to lateral light but with time, horizontal swimming rates (HSRs) from release point to light source progressively declined. When measured over a range of light quantities, HSRs peaked at 30 microM/m2/s. HSRs were also influenced by water temperature. A rapid increase occurred up to 15 degrees C after which there was a precipitous decline. HSRs to coloured light were negatively correlated with increasing wavelength. When offered a choice between colours, cercariae favoured the shorter wavelengths. The implications of these responses for successful transmission are discussed.

Animals↗
PubMed1992

The effects of computer-controlled shadow stimuli on the success of cercarial transmission by Cryptocotyle lingua (Digenea: Heterophyidae).

Pectoral fins from juvenile rainbow trout (Oncorhynchus mykiss) were used in a bioassay, the object of which was to quantify the effect of simulated shadow stimuli on the transmission success of the cercariae. For a period of 60 min, parasites and fins were exposed to a sequence of computer-controlled shadow stimuli, continuous light or total darkness, and subsequently the number of infections was counted. Trials were conducted with cercariae 1, 12 and 24 h old. Within the constraints of the experimental procedure, shadows were found to increase significantly the number of infections achieved by the 12-h-old parasites. As the cercariae aged, their ability to infect host tissue declined. The relevance of these results to transmission in the natural environment is discussed.

Animals↗
PubMedDate not supplied

Life history of Pygidiopsis crassus n. sp. (Trematoda, Digenea, Heterophyidae) in the neotropical region.

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.

Animals↗
PubMed1994

Stictodora fuscatum (Heterophyidae) metacercariae encysted in gobies, Acanthogobius flavimanus.

The metacercariae of the genus Stictodora encysted in gobies, Acanthogobius flavimanus, purchased from a local market of Haenam-gun, Chollanam-do, were identified as those of S. fuscatum. A total of 1,437 metacercariae were collected from 30 gobies and some of them were orally fed to cats in order to obtain the adult worms. The metacercariae were 0.194-0.301 mm by 0.168-0.270 mm in size, yellowish brown, round to elliptical, and with a thin and transparent cyst wall. The excysted larvae were 0.280-0.423 mm long and 0.150-0.184 mm wide, beset with numerous tegumental spines on the anterior half of the body, and equipped with a characteristic ventrogenital sac. Total 21 adult worms were recovered from 2 cats 7 days after infection. The adult worms were small, leaf-like, 0.514-0.918 mm long and 0.235-0.377 mm wide. The ventrogenital sac was elliptical and its gonotyl was armed with 13-18 spines which were radially arranged and appeared as fan-shape. It has been confirmed that A. flavimanus is a second intermediate host of S. fuscatum in Korea.

Animals↗
PubMed1989

Phagicola angrense (Digenea: Heterophyidae) as a cause of enteritis in a raccoon (Procyon lotor).

Numerous Phagicola angrense were associated with enteritis in a single male juvenile raccoon (Procyon lotor) live-trapped on Parramore Island, Virginia (USA). The raccoon was weak, ataxic and had melenic soft feces. The carcass was emaciated, pale and had ascites. Mesenteric vessels appeared prominent and the stomach and the intestines contained fetid bloody material. The small intestinal mucosa contained three locally extensive sites of necrosis. Histopathologically, there were numerous small digeneans both attached to the mucosa and free within the lumen. Digeneans were usually found deep within the crypts where the epithelium was markedly attenuated and devoid of epithelial cells at the point of parasite attachment. In the lamina propria there were areas of acute hemorrhage and infiltration with plasma cells and eosinophils. This appears to be the first record of severe enteritis in the raccoon caused by this digenean.

Animals↗
PubMed1975

The sensory receptors of two cercariae from Malaysia: Trichobilharzia brevis (Schistosomatidae) and Haplorchis Pumilio (Heterophyidae).

A description of sensory receptors of Trichobilharzia brevis is given. They are compared with the five Schistosomatidae described by Richard (1971), namely, Trichobilharzia ocellata, schistosoma mansoni, S. bovis, S; haematobium and S. rodhaini. All these species display very similar chaetotaxic characters. In the study of the cercaria of Haplorchis pumilio, comparison with the few Opisthorchioidea cercarial sensory organs already known has enabled the authors to characterise the chaetotaxy for this superfamily.

Animals↗