The stimulation of daughter redia production during the larval development of Fasciola hepatica

SummaryIn snails maintained at 20 °C rediae of Fasciola hepatica emerge from sporocysts from 11 days after infection onwards. The number of mother rediae rises steadily thereafter until at least 40 days after infection. Daughter rediae are seldom observed in mother rediae dissected from snails maintained at 20 °C. Their production can, however, be stimulated by subjecting the snail host to starvation, to low, and to high temperature shocks. The parasite is susceptible to stress from immediately after infection for about 16 days, when maintained at 20 °C. In general, the more extreme the shock, the greater is daughter redial production. Increasing the length of the period of stress from 12 h up to 9 days does not increase the production of daughter rediae, nor does repeated on/off cold shocks or continuous maintenance at 10 °C. Daughter rediae develop more rapidly than cercariae and leave the mother rediae several days earlier. There is no evidence that presence of daughter rediae coincides with the suppression of cercarial production. The findings are discussed with reference to possible mechanisms by which parasite development might be controlled.

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The influence of temperature on the succession of redial and cercarial generations of Fasciola gigantica in a snail host

Parasitology ◽

10.1017/s0031182000074321 ◽

1964 ◽

Vol 54 (1) ◽

pp. 59-65 ◽

Cited By ~ 27

Author(s):

J. A. Dinnik ◽

N. N. Diknik

Keyword(s):

Larval Development ◽

Low Temperatures ◽

First Generation ◽

Cold Season ◽

Snail Host ◽

Fasciola Gigantica ◽

Natural Conditions ◽

Influence Of Temperature ◽

Cercarial Production ◽

Influence Of Temperature On

Experiments on the larval development of Fasciola gigantica carried out under natural conditions have shown that at temperatures of 16° C. or less the rediae did not produce cercariae. The first-generation rediae, developed from the sporocyst, and all the rediae of subsequent generations produced only daughter rediae and did not change over to the production of cercariae as long as the low temperatures of the cold season lasted.As soon as the cold season ended and the temperature of the water in the aquaria containing the infected snails rose to a mean maximum of 20° C. all the rediae switched from redial to cercarial production.

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Dynamics of the intramolluscan larval development of Schistosoma haematobium: replication of daughter sporocysts and cercarial production

Journal of Helminthology ◽

10.1017/s0022149x00008634 ◽

1989 ◽

Vol 63 (1) ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

N. Kechemir ◽

A. Théron

Keyword(s):

Larval Development ◽

Schistosoma Haematobium ◽

Snail Host ◽

Bulinus Truncatus ◽

Cercarial Production

ABSTRACTDuring the intramolluscan larval development of Schistosoma haematobium (Algerian strain) in Bulinus truncatus, two replication processes of daughter sporocysts occur. Replication by direct sporocystogenesis appears more important than sporocystogenesis post cercariogenesis. These mechanisms assure a periodic renewal of the sporocyst stock in the snail host and seem to be synchronized with the development of cercarial generations. The succession of several generations of cercariae is responsible for the alternation of high and low periods of productivity.The scheme proposed for the intramolluscan development of S. haematobium is compared with those described for S. mansoni and S. bovis and interpreted in terms of demographic strategies adapted to a better exploitation of the snail host.

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Larval development of Fasciola hepatica in experimental infections: variations with populations of Lymnaea truncatula

Journal of Helminthology ◽

10.1079/joh2002112 ◽

2002 ◽

Vol 76 (2) ◽

pp. 179-183 ◽

Cited By ~ 13

Author(s):

P. Vignoles ◽

G. Dreyfuss ◽

D. Rondelaud

Keyword(s):

Retrospective Study ◽

Genetic Variability ◽

Larval Development ◽

Experimental Infection ◽

Fasciola Hepatica ◽

The Other ◽

Mammalian Host ◽

Cercarial Production ◽

Lymnaea Truncatula ◽

Low Prevalence

AbstractA retrospective study was undertaken on 70 French populations of Lymnaea truncatula experimentally infected with Fasciola hepatica to determine whether or not susceptibility of snails to infection influenced redial and cercarial production. Results were compared with those obtained from two control populations, known for prevalences higher than 60% when experimentally infected with F. hepatica. In the 70 other populations examined, the prevalences ranged from 2 to 75%. In 55 of these populations, where the prevalence was more than 20%, a high proportion (50.1–56.8%) of snails died after cercarial shedding, whereas in the other groups (non-shedding snails with the most differentiated larvae being free cercariae, rediae containing cercariae, immature rediae, or sporocysts, respectively), snail death was significantly less. In 11 populations, where the prevalence values were 5–19%, only 14% of snails died after cercarial shedding, whereas snails with free cercariae, rediae with cercariae, or immature rediae showed significant increases in snail mortality. In the remaining four snail populations, with prevalences of less than 5%, the most differentiated larval forms were only immature rediae and/or sporocysts. Overall, the number of rediae containing cercariae significantly decreased with decreasing prevalence values. The low prevalence of experimental infection in several populations of snails might be explained by the occurrence of natural infections with miracidia originating from a mammalian host other than cattle, and/or by genetic variability in the susceptibility of snails to infection.

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Prevalence and intensity of infections in the lymnaeid snail Omphiscola glabra experimentally infected with Fasciola hepatica, Fascioloides magna and Paramphistomum daubneyi

Journal of Helminthology ◽

10.1017/s0022149x07161162 ◽

2007 ◽

Vol 81 (1) ◽

pp. 7-12 ◽

Cited By ~ 4

Author(s):

G. Dreyfuss ◽

A. Novobilský ◽

P. Vignoles ◽

V. Bellet ◽

B. Koudela ◽

...

Keyword(s):

Intermediate Host ◽

Larval Development ◽

Fasciola Hepatica ◽

Fascioloides Magna ◽

Post Exposure ◽

Cercarial Production ◽

Lymnaeid Snail

AbstractSingle and double infections of juvenile Omphiscola glabra (Gastropoda: Lymnaeidae) with Paramphistomum daubneyi and/or Fasciola hepatica were carried out to determine the redial burden and cercarial production in snails dissected at day 60 or at day 75 post-exposure (p.e.) in the laboratory at 20°C. The results were compared with those obtained with single-miracidium infections by Fascioloides magna. Compared to F. hepatica, low values were noted at day 75 p.e. for the prevalence of snail infections with P. daubneyi (4.6–8.3% instead of 23.6–25.9%), the total number of free rediae (10.7–17.9 per snail instead of 26.3–34.7), and that of free cercariae (112.8–136.9 per snail instead of 177.8–248.5). Despite a greater number of free rediae at day 75 p.e. (36.2–45.6 per snail), the prevalences of snail infections with F. magna and cercarial production were similar to those noted for F. hepatica. The results concerning F. hepatica and P. daubneyi might partly be explained by a progressive adaptation of O. glabra to sustain the larval development of these digeneans over the years, as this snail is a natural intermediate host of F. hepatica and P. daubneyi in central France since 1995. Compared with the high number of fully-grown rediae of F. magna in O. glabra, cercarial production seemed limited and this might be explained by the presence of high numbers of rediae which reduced the avaibility of nutrients for cercarial differentiation within the snail.

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Studies of the relationships between Schistosoma nasale and S. spindale and their snail host Indoplanorbis exustus

Journal of Helminthology ◽

10.1017/s0022149x00010361 ◽

1991 ◽

Vol 65 (1) ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

J. de Bont ◽

J. Vercruysse ◽

D. van Aken ◽

V. R. Southgate ◽

D. Rollinson

Keyword(s):

Sri Lanka ◽

Intermediate Host ◽

Snail Host ◽

Infection Rates ◽

Death Rates ◽

Cercarial Production ◽

Indoplanorbis Exustus ◽

Level 1 ◽

Host Parasite ◽

Opposite Tendency

ABSTRACTInfectivity and cercarial production of Indoplanorbis exustus related to variation of miracidial dose (1, 4, 10 or 20) with Schistosoma nasale and S. spindale from Sri Lanka were studied. The intermediate host-parasite relationships of the two schistosome species showed marked differences under the conditions of observation recorded in this study. Prepatent death rates (PDR) were on average higher for S. spindale (30%) than for S. nasale (10%). The size of the miracidial dose to which snails had been exposed had no effect on PDR. The infection rates (IR) were on average higher for S. nasale (41%) compared with S. spindale (27%). Highest IR occurred after exposure to 4 miracidia in S. nasale infections (79%) and after exposure to 10 miracidia in S. spindale infections (6O%). The highest daily average cercarial production per snail was recorded for S. nasale at a level of 4 miracidia (1311), and for S. spindale at a level of 10 miracidia (1615). At low level (1 or 4 miracidia) of exposure, I. exustus showed a better compatibility with S. nasale than with S. spindale. An opposite tendency was observed at higher levels (10 or 20 miracidia) of exposure. Unsuccessful infections of Lymnaea luteola with either S. nasale or S. spindale indicate that this species is not involved in transmission.

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Pseudosuccinea columella (Say 1817) (Gastropoda, Lymnaeidae), snail host of Fasciola hepatica: first record for France in the wild

Parasitology Research ◽

10.1007/s00436-007-0656-y ◽

2007 ◽

Vol 101 (5) ◽

pp. 1389-1392 ◽

Cited By ~ 24

Author(s):

Jean-Pierre Pointier ◽

Christine Coustau ◽

Daniel Rondelaud ◽

André Theron

Keyword(s):

Fasciola Hepatica ◽

First Record ◽

Snail Host ◽

In The Wild

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Fasciola hepatica larval development within the intermediate host.

10.1079/9781789246162.0002 ◽

2021 ◽

pp. 23-64

Author(s):

Gilles Dreyfuss ◽

Philippe Sindou ◽

Philippe Hourdin ◽

Philippe Vignoles ◽

Daniel Rondelaud

Keyword(s):

Intermediate Host ◽

Larval Development ◽

Fasciola Hepatica ◽

Parasitic Infections ◽

Snail Species ◽

Larval Behavior ◽

Host Snail

Abstract This book chapter focuses on host snail species and larval behavior forms in snails, and features of parasitic infections in naturally or experimentally infected snails, or in coinfected snails.

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Development ofFasciola hepaticainLymnaea columellainfected with miracidia derived from cattle and marmoset infections

Journal of Helminthology ◽

10.1017/s0022149x07873585 ◽

2008 ◽

Vol 82 (1) ◽

pp. 81-84 ◽

Cited By ~ 6

Author(s):

E.A. Mendes ◽

W.S. Lima ◽

A.L. de Melo

Keyword(s):

Survival Rate ◽

Intermediate Host ◽

Post Infection ◽

Fasciola Hepatica ◽

Bos Taurus ◽

Snail Host ◽

Vertebrate Host ◽

Infection Rates ◽

Host Origin ◽

Cattle Faeces

AbstractThe development ofFasciola hepaticafrom two species of definitive hosts, i.e. cattle (Bos taurus) and a marmoset (Callithrix penicillata) in the snailLymnaea columellawas determined based on the production of rediae and cercariae and snail survival rate. More rediae and cercariae at 60–74 days post-infection were produced by snails infected by cattle-derived miracidia (cattle group) than by those infected by marmoset-derived miracidia (marmoset group). Among theL. columellaparasitized by the marmoset group, the survival rate and the percentage of positive snails were higher than among those parasitized by the cattle group. Eggs ofF. hepaticareleased in cattle faeces were significantly bigger than those released in marmoset faeces. Miracidia originating from parasites that completed their development in cattle were more efficient in infecting the intermediate host. These results suggest that vertebrate-host origin influences the eggs produced by the parasite and the infection rates in the snail hostL. columella.

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