Studies on the life-cycle ofHimasthla militaris(Trematoda: Echinostomatidae): influence of temperature and salinity on the life-span of the miracidium and the infection of the first intermediate host,Hydrobia ventrosa

Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 131-135 ◽  
Author(s):  
R. Vanoverschelde
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Intermediate Host ◽  
Half Life ◽  
Snail Host ◽  
Influence Of Temperature ◽  
First Intermediate Host

SUMMARYThe influence of temperature and salinity on miracidial longevity and miracidial infectivity of the digenean,Himasthla militaris, has been examined. At 14, 25 and 30 °C the half-life of the miracidia was 1200, 630 and 420 min respectively, and infection of the first intermediate host,Hydrobia ventrosa, only occurred at 25 and 30 °C, for both temperatures 52% became infected. In the range 2·1 to 34‰ (2·1, 4·2, 8·5, 17 and 34‰) the miracidia had a minimal and maximal half-life of 60 and 630 min in water with a salinity of 2·1 and 17‰ respectively, while the infection of the snail host was possible only in water with a salinity of 8·5 and 17‰.

Observations on the Morphology and Life Cycle ofNeodiplostomum intermedium(Trematoda: Diplostomatidae)

Parasitology ◽  
1961 ◽  
Vol 51 (1-2) ◽  
pp. 133-172 ◽  
Author(s):  
J. C. Pearson
Keyword(s):  
Life Cycle ◽  
Special Reference ◽  
Intermediate Host ◽  
Technical Assistance ◽  
Snail Host ◽  
Tree Frog ◽  
Mother Sporocyst ◽  
Egg Transformation ◽  
Hydromys Chrysogaster ◽  
Paratenic Hosts

1.Neodiplostomum intermediumPearson is recorded from four new hosts; as an adult from the water rat,Hydromys chrysogasterGeoffroy, and as a metacercaria (diplostomulum), from tadpole and adult of an undescribed tree frog,Hylasp., tadpole of (Hyla latopalmata(Günther)Mixophyes fasciolatusGünther and frog of an unidentified leptodactylid.2. The life cycle ofNeodiplostomum intermediumwas followed experimentally; the hosts were:Pettancylus assimilis(Petterd), a fresh-water limpet, as first intermediate host; tadpole ofHyla pearsoniCopland as second intermediate host;Hyla caerulea(Shaw) a tree frog, andHemisphaerodon gerrardiPeters, the pinktongued skink, as paratenic hosts; andRattus assimilis(Gould) and laboratory rats as definitive hosts.3. Descriptions are given of the morphology of the miracidium, mother sporocyst, daughter sporocyst, cercaria, and diplostomulum, with special reference to the structure of the miracidium and of the cercarial tail.4. Observations are given on the embryology of the miracidium, hatching of the egg, transformation of the miracidium into the mother sporocyst with special reference to the germinal cells, the route and manner of escape of cercariae from the snail host, the development of the diplostomulum with special reference to the reserve excretory system, and the movements of diplostomula during metamorphosis of the tadpole host.5. The haploid chromosome number is ten, as determined from squashes of testes. One paratype and a series of experimental adults have been compared with and found different fromNeodiplostomum(Fibricola)sarcophilusn.comb. The orthography and formal proposing of the names of the species ofFibricolatransferred toNeodiplostomumby Pearson (1959b) are corrected.The writer wishes to thank Dr M. J. Mackerras, Queensland Institute for Medical Research, for generously supplying water rats; Professor J. F. A. Sprent, University of Queensland Veterinary School, for his criticism of the manuscript; Mr K. Webber and his sons for their assistance in catching rats and for permission to collect snails, frogs and tadpoles from their streams; and Mr R. J. Ballantyne for technical assistance. This study was supported by a grant from the Rural Credits Fund of the Commonwealth Bank of Australia.

Life cycle studies on two Digenea, Paradistomum geckonum (Dicrocoeliidae) and Mesocoelium sociale (Mesocoeliidae), in geckonid lizards from Indonesia

1987 ◽  
Vol 65 (10) ◽  
pp. 2491-2497 ◽  
Author(s):  
Murray J. Kennedy ◽  
L. M. Killick ◽  
M. Beverley-Burton
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Intermediate Hosts ◽  
Larval Stages ◽  
Hemidactylus Frenatus ◽  
Pulmonate Gastropod ◽  
First Intermediate Host

Life cycle studies of Paradistomum geckonum (Dicrocoeliidae) were attempted experimentally. The pulmonate gastropod Lamellaxis gracilis served as the first intermediate host; geckonid lizards (Cosymbotus platyurus, Gehyra mutilata, and Hemidactylus frenatus) served as definitive hosts. The life cycle of Mesocoelium sociale (Mesocoeliidae) was studied in naturally infected first intermediate hosts (L. gracilis, Huttonella bicolor) and experimentally in geckonid definitive hosts (C. platyurus, G. mutilata, and H. frenatus). Some naturally infected L. gracilis were infected concurrently with larval stages of both digeneans. Second intermediate hosts, presumed to be arthropods, were experimentally unnecessary. Metacercariae of P. geckonum were not found. Cercariae of M. sociale formed encysted metacercariae in the same individual snails.

The Life-Cycle and Morphology of Stemmatostoma-Pearsoni, Gen Et Sp-Nov, With Notes on the Morphology of Telogaster-Opisthorchis Macfarlane (Digenea, Cryptogonimidae)

1986 ◽  
Vol 34 (2) ◽  
pp. 279 ◽  
Author(s):  
TH Cribb
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Freshwater Fish ◽  
Oral Sucker ◽  
Intermediate Hosts ◽  
Redial Generation ◽  
Adult Morphology ◽  
Mother Sporocyst ◽  
First Intermediate Host ◽  
Prosobranch Snail

Stemmatostoma pearsoni, gen. et sp. nov., is described from the intestine of Leiopotherapon unicolor (Gunther) and Macquaria novemaculeata (Steindachner) in Queensland. Stemmatostoma is placed within the Neochasminae and is distinguished by its long oesophagus, compact ovary, short caeca, pre-ovarian vitellaria, simple gonotyl and funnel-shaped oral sucker. The diagnosis of the Neochasminae is emended excluding Parspina Pearse. Telogaster opisthorchis Macfarlane is recorded from the intestine of Anguilla reinhardtii Steindachner from Victoria. The spinose oral suckers of S. pearsoni and T. opisthorchis are capable of being retracted into tegumental pockets. It is postulated that this arrangement may be widespread amongst spinose cryptogonimids. The first intermediate host of S. pearsoni is Posticobia brazieri (Smith), a prosobranch snail. The second intermediate hosts are freshwater fish: Hypseleotris galii (Ogilby), H. compressus (Krefft), Mogurnda mogurnda (Richardson), M. adspersa (Castelnau), Philypnodon grandiceps (Krefft), Gobiomorphus australis (Krefft), and Pseudomugil signifer Kner. Within the snail there is a mother sporocyst generation, a redial generation and a cercarial generation. Development of the mother sporocyst is similar to that described for other opisthorchioids. Cryptogonimid cercariae are characterized by 16 flame-cells, pre-vesicular penetration glands, dorso-ventral caudal finfolds and absence of body pigmentation. On the basis of cercarial and adult morphology it is proposed that Pseudexorchis Yamaguti be excluded from the Cryptogonimidae.

Experimental studies on the transmission dynamics of the cercariae of Echinoparyphium recurvatum (Digenea: Echinostomatidae)

Parasitology ◽  
1983 ◽  
Vol 87 (1) ◽  
pp. 167-174 ◽  
Author(s):  
N. A. Evans ◽  
D. M. Gordon
Keyword(s):  
Life Span ◽  
Intermediate Host ◽  
Experimental Studies ◽  
Intermediate Hosts ◽  
Maximum Life Span ◽  
Age Dependent ◽  
Second Intermediate Host ◽  
The Mean ◽  
The Relationship ◽  
First Intermediate Host

SUMMARYAge-dependent survival and infectivity characteristics are described for the cercariae of Echinoparyphium recurvatum. At 18 °C the maximum life-span of the cercariae was 48 h and 50% survival occurred at 30·5 h. Infectivity of cercariae to the second intermediate host, Lymnaea peregra was maximal approximately 2 h after emission from the first intermediate host and it subsequently declined to zero at 19 h. It is suggested that the period of sub-maximal infectivity at the beginning of the cercarial life-span may represent a phase during which dispersal is an important function of the larvae. The relationship between infective stage density and establishment success was linear up to densities equivalent to 5000 cercariae/1. At higher cercarial densities the proportion of parasites establishing in second intermediate hosts declined progressively with increasing cercarial density. The mean number of parasites establishing/host increased linearly with increasing host size.

Occurrence of the Metacercariae, of Cotylurus erraticus (Rudolphi, 1809) Szidat, 1928 (Digenea: Strigeidae) in Brown Trout Salmo trutta L., and Rainbow Trout S. gairdneri Richardson, 1836, from Hanningfield Reservoir, Essex

1973 ◽  
Vol 47 (4) ◽  
pp. 389-398 ◽  
Author(s):  
R. Wootten
Keyword(s):  
Life Cycle ◽  
Rainbow Trout ◽  
Intermediate Host ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Pericardial Cavity ◽  
Brown Trout Salmo Trutta ◽  
First Intermediate Host

Brown and rainbow trout from Hanningf?eld Reservoir, Essex and rainbow trout from associated raceways were found to be infected with the metacercariae of Cotyluriis erraticus throughout 1968. Both o brown and rainbow trout of age 2+ introduced into the reservoir in the spring became heavily infected with C. erraticus during their first summer in the reservoir. Rainbow trout were more heavily infected than brown trout. Infection increased with age in rainbow trout but this was not apparent in brown trout. The metacercariae are almost completely restricted to the pericardial cavity of the trout. The life-cycle of C. erraticus in Hanningfield possibly involves gulls as final hosts and the gastropod Valvata piscinalis as first intermediate host. C. erraticus has probably been introduced into the reservoir in infected trout from outside sources, or by infected avian final hosts.

The life cycle of Paramphistomum microbothrium Fischoeder, 1901 (Trematoda, Paramphistomidae)

Parasitology ◽  
1954 ◽  
Vol 44 (3-4) ◽  
pp. 285-299 ◽  
Author(s):  
J. A. Dinnik ◽  
N. N. Dinnik
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Intermediate Host ◽  
East Africa ◽  
Laboratory Experiments ◽  
First Generation ◽  
Infected Snail ◽  
Successive Generations ◽  
Whole Life Cycle ◽  
Further Development

The whole life cycle of Paramphistomum microbothrium Fischoeder, 1901, found in cattle of Kenya, East Africa, has been established experimentally.In laboratory conditions, the eggs hatched miracidia on the 14th to 16th day, if they were kept in water at a temperature of 26–28° C.In a snail, Bulinus alluaudi (Dautzenberg), kept at the temperature of 18–20° C., the miracidium developed into a sporocyst, the elongated body of which, containing young rediae, reached a length of 3·6 mm. in about 2 weeks.The first rediae which emerged from a sporocyst were observed on the 14th day, and on the 20th day the first generation rediae began to produce second-generation rediae. From the 28th day onward the first-generation parent rediae ceased to produce daughter rediae and began to develop cercariae only. This period of production of cercariae by the redia lasted about 30 days, and when the life of the first-generation rediae drew to its close, the old rediae developed a few daughter rediae again.Cercariae began to emerge from the first-generation rediae 30 days after exposure of the snail to miracidia. The cercariae left the parent redia in a very immature state and further development occurred in the liver of the snail. The emergence of cercariae from the infected snail began on the 43rd day after exposure to miracidia. Shortly after emerging from the snail, the cercariae attached themselves to vegetation and encysted.Development of rediae of the second, third, fourth and apparently more successive generations followed an identical course to that outlined for the rediae of the first generation. As a result the successive generations of rediae maintain the infection going in an intermediate host and the infected snails were continually shedding cercariae as long as they lived. In the laboratory experiments the life span of some of the infected snails exceeded a year.In cattle infected experimentally P. microbothrium reached maturity and began passing out the eggs about a 100 days after the encysted cercariae were fed to the animals.

The Life History of Gastrodiscoides hominis (Lewis and McConnel, 1876) Leiper, 1913– the Amphistome Parasite of Man and Pig

1972 ◽  
Vol 46 (1) ◽  
pp. 35-46 ◽  
Author(s):  
S. C. Dutt ◽  
H. D. Srivastava
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Intermediate Host ◽  
Definitive Host ◽  
Growth And Development ◽  
Snail Host ◽  
Adult Fluke ◽  
History Of

The life cycle of Gastrodiscoidcs hominis has been described using Helicorbis coenosus as the experimental intermediate host and the pig as the definitive host.The morphology of the miracidium, redia and metacercaria has been described. Data have been furnished on the infection and longevity, of and production of cercariae by the snail host, and the growth and development of the adult-fluke in the definitive host.

Life cycle of Gnathostoma nipponicum Yamaguti, 1941

1992 ◽  
Vol 66 (1) ◽  
pp. 53-61 ◽  
Author(s):  
K. Ando ◽  
H. Tokura ◽  
H. Matsuoka ◽  
D. Taylor ◽  
Y. Chinzei
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Experimental Infection ◽  
Definitive Host ◽  
Field Survey ◽  
Paratenic Host ◽  
Third Stage ◽  
Second Intermediate Host ◽  
First Intermediate Host

ABSTRACTThe life cycle of Gnathostoma nipponicum was examined by field survey and by experimental infection of animals with the larvae. Naturally infected larval G. nipponicum were found in loaches, catfish, and snakes. Experimentally, loaches, killifishes, frogs, salamanders, mice, and rats were successfully infected with the early third-stage larvae of G. nipponicum obtained from copepods (the first intermediate host), whereas snakes, quails, and weasels were not. Frogs, snakes, quails, and rats were experimentally infected with the advanced third-stage larvae (AdL3) from loaches. These results reveal that some species of fishes, amphibians and mammals can act as the second intermediate host and that some species of reptiles, birds and mammals can act as a paratenic host. The life cycle was completed in weasels, the definitive host, which were infected with AdL3 from loaches and started to evacuate eggs of G. nipponicum in faeces on days 65–90 postinfection.

Heterophyes species in Greece: record of H. heterophyes, H. aequalis and H. dispar from the first intermediate host, Pirenella conica

1987 ◽  
Vol 61 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Horst Taraschewski ◽  
Artemis Nicolaidou
Keyword(s):  
Intermediate Host ◽  
Snail Host ◽  
Focus Of Infection ◽  
Human Infections ◽  
First Time ◽  
First Intermediate Host

ABSTRACTHeterophyes heterophyes is reported for the first time from the snail host Pirenella conica in Greece. H. aequalis and H. dispar are reported for the first time from Greece and from Europe. The results presented, together with the available data on necropsies of dogs and cats, human infections and the biotope preference of the snail, suggest that Greece is an important focus of infection in Europe.

The Early Development of Contracaecum osculatum

1969 ◽  
Vol 43 (3-4) ◽  
pp. 293-298 ◽  
Author(s):  
J. T. Davey
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Early Development ◽  
Stage Larva ◽  
Grey Seal ◽  
Second Stage ◽  
Harpacticoid Copepods ◽  
Different Temperatures ◽  
Contracaecum Osculatum ◽  
First Intermediate Host

1. Eggs of Contracaecum osculatum, extracted from grey seal faeces, have been hatched in the laboratory at different temperatures and the morphology and behaviour of the larvae described.2. Artificial exsheathment of the second stage larva from the first stage cuticle has been demonstrated.3. In attempting to establish the first intermediate host of the life cycle, two species of harpacticoid copepods have been successfully infected but no significant developments reported.

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