scholarly journals STUDY OF MOLLUSCS’ INFESTATION WITH FASCIOLA HEPATICA IN BRYANSK REGION

2019 ◽  
pp. 481-486
Author(s):  
Postevoy ◽  
Andreyanov ◽  
Puzanova
Keyword(s):  
Intermediate Host ◽  
Infection Rate ◽  
Fasciola Hepatica ◽  
Pond Snail ◽  
Stages Of Development ◽  
Larval Stages ◽  
Development Cycle ◽  
Lymnaea Truncatula

The intermediate host of Fasciola hepatica is Lymnaea truncatula mollusk. However, participation of other species of mollusks (L. stagnalis, Galba palustris, etc.) in the development cycle of F. hepatica is not excluded. In this connection, we have studied the distribution of mollusks of these species in the territory of the Bryansk region. The aim of the work was to carry out a study on the invasion of fasciol larvae of mollusks on pastures of trematodiasis-unfriendly farms of the Bryansk region. On farms, the density of mollusks and their species, as well as the dynamics of the infection of mollusks by the partenite stages of F. hepatica, were determined. The work was carried out from May to October 2018 on 3 pastures with an area of 2 to 5 hectares. The study was subjected to mollusks: small pond snail L. truncatula in the amount of from 149 to 151 specimens, ordinary pond snail – L. stagnalis from 10 to 18 specimens, marsh pond snail – L. palustris from 30 to 85 specimens, iushkoviy pond snail – L. auricularia from 4 to 21 specimens. Mollusks were examined every month during the pasture period (May-October) for infection with fasciol larvae by the compressor method. It was revealed that only small pond snail L. truncatula was infested by the larval stages of development of fasciol. The rest of the limneids were free from this trematodase invasion. The small pond snail was infected more intensely in September. The fasciol larvae of the small pond snail were recorded in May, June, August and September; the infection rate was 1.3%, 2.6%, 6.6% and 8%, respectively.

Fasciola hepatica: the infection rate and the development of redial generations in Lymnaea truncatula exposed to miracidia after experimental desiccation and activation in water

1994 ◽  
Vol 68 (1) ◽  
pp. 63-66 ◽  
Author(s):  
D. Rondelaud
Keyword(s):  
Infection Rate ◽  
First Generation ◽  
Second Generation ◽  
Fasciola Hepatica ◽  
The Other ◽  
Lymnaea Truncatula

AbstractAdult Lymnaea truncatula were subjected to 10 days of experimental desiccation and then remained in water for 1 or 8 days before each was exposed to a single miracidium. The infection rate was lower in these snails than in infected controls that were not exposed to stress (52–54% vs 73%). The redial burden clearly decreased in stressed snails (18–25 rediae per snail) than in controls (43 rediae). This numerical decrease concerned essentially: i) live independent rediae of the first generation and the first cohort of the second generation, and ii) dependent rediae of subsequent generations. Mature rediae were more numerous in the first cohort of the second generation than in the other generations. Desiccation before exposure limited the size of the redial burden but placement in water for 8 days just after the stress attenuated the effects of this factor.

The distribution ofFasciola hepaticaandFasciola giganticawithin southern Tanzania – constraints associated with the intermediate host

Parasitology ◽  
2008 ◽  
Vol 135 (4) ◽  
pp. 495-503 ◽  
Author(s):  
S. M. WALKER ◽  
A. E. MAKUNDI ◽  
F. V. NAMUBA ◽  
A. A. KASSUKU ◽  
J. KEYYU ◽  
...  
Keyword(s):  
High Altitude ◽  
Intermediate Host ◽  
East Africa ◽  
Fasciola Hepatica ◽  
Molecular Data ◽  
Climatic Conditions ◽  
Fasciola Gigantica ◽  
Rrna Gene ◽  
28S Rrna ◽  
Lymnaea Truncatula

SUMMARYIn East Africa,Fasciola giganticais generally the causative agent of fasciolosis but there have been reports ofF. hepaticain cattle from highland regions of Kenya, Ethiopia, Uganda and Zaire. The topography of the Southern Highlands of Tanzania provides an environment where the climatic conditions exist for the sustenance of lymnaeid species capable of supporting bothFasciola hepaticaandF. gigantica. Theoretically this would allow interaction between fasciolid species and the possible creation of hybrids. In this report we present molecular data confirming the existence of the snail,Lymnaea truncatula, at high altitude on the Kitulo Plateau of the Southern Highlands, Tanzania, along with morphometric and molecular data confirming the presence ofF. hepaticain the corresponding area. At lower altitudes, where climatic conditions were unfavourable for the existence ofL. truncatula, the presence of its sister speciesL. natalensiswas confirmed by molecular data along with its preferred fasciolid parasite,F. gigantica. Analysis based on a 618 bp sequence of the 28S rRNA gene did not reveal the presence of hybrid fasciolids in our fluke samples.

Microsatellites in the hermaphroditic snail,Lymnaea truncatula, intermediate host of the liver fluke,Fasciola hepatica

2000 ◽  
Vol 9 (10) ◽  
pp. 1662-1664 ◽  
Author(s):  
S. Trouvé ◽  
L. Degen ◽  
C. Meunier ◽  
C. Tirard ◽  
S. Hurtrez-Boussès ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Liver Fluke ◽  
Fasciola Hepatica ◽  
Lymnaea Truncatula

Molluscs interfering with the capacity of Fasciola hepatica miracidia to infect Lymnaea truncatula

Parasitology ◽  
1976 ◽  
Vol 73 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Niels Ørnbjerg Christensen ◽  
Peter Nansen ◽  
Flemming Frandsen
Keyword(s):  
Infection Rate ◽  
Fasciola Hepatica ◽  
Host Finding ◽  
Decoy Effect ◽  
Bithynia Tentaculata ◽  
Lymnaea Truncatula

Fasciola hepatica miracidia labelled with radioselenium were used to study aspects of their host-finding capacity by determining radioactivity subsequently taken up by exposed ‘target’ snails (Lymnaea truncatula). Possible interfering effects exercised by a number of non-host snails and bivalves were examined in linear test channels. The infection rate (radioactivity) among ‘target’ snails was markedly lowered when non-host Lymnaea species (L. pereger, L. palustris, L. stagnalis) were interposed as ‘decoys’. The prosobranch Bithynia tentaculata and the bivalve Sphaeriwm corneum exhibited a slight decoy effect whereas pulmonate species like Anisus vortex, Gyraulus albus, Planorbis planorbis, Physa fontinalis did not interfere with miracidial host-finding.Other experiments showed that miracidia are more strongly attracted towards L. truncatula than L. pereger. Miracidia are not able to penetrate intact egg clusters of L. truncatula.

Methodical guidelines on the control of fasciolosis in cattle in the Kaluga region

2018 ◽  
Vol 12 (2) ◽  
pp. 108-116
Author(s):  
A.M. Ustinov ◽  
R.T. Safiullin ◽  
R.R. Safiullin
Keyword(s):  
Infected Animal ◽  
Fasciola Hepatica ◽  
Adult Stage ◽  
Federal District ◽  
Dosage Forms ◽  
Pond Snail ◽  
Meat Processing ◽  
Processing Plants ◽  
Causative Agents ◽  
Kaluga Region

Information is provided on the causative agents of fasciolosis and the developmental biology of Fasciola hepatica. Fasciolosis of cattle is widespread in the conditions of the Kaluga Region and the Central Federal District on farms of different forms of ownership. The greatest number of F. hepatica eggs in 1 g of feces in cattle is established in JSC "Iskra" - 175,4 specimens, the lowest - in the samples from cows from private farms - 87,6 sp. At the opening slaughter of cattle at meat processing plants region and slaughterhouses invasion of their fasciolae was 34.8%. The average number fascial one infected animal was 32.1 specimens, including adult - and larval specimens of 25.2 and 6.9 copies At veterinary-sanitary expertise and helminthological autopsy of the liver, gallbladder and bile ducts installed year-round invasion fasciolae mainly in the adult stage. Young animals of the current year are infected with fasciola in the pasture massly in August-September, and the extent of invasion in November was 4.3%, for winter-stabling months an average of 12.6%, in March - 17.9% and in April after de-worming - 5.9%.The data obtained in the study of the distribution of the small pond has shown that in the Kaluga region these mollusks are widespread. In this case, the invasion of the small pond snail by larval forms of fasciolae in different years has its own peculiarities, which are influenced by climatic factors.The different dosage forms of clozantel - Rolenol and Santel and Genamectin with mixed fascioliasis and hypodermatosis of bovine in the recommended dose against subcutaneous gadfly larvae - provided 100% efficacy. The tested dosage forms of clozantel are similar in effectiveness against subcutaneous gadfly larvae (EE-100%) and fasciol (EE-95 and 90%, IE-97.4 and 96.3%).The therapeutic and economic effectiveness of complex domestic preparations of Helmicide and Fascocida in spontaneous fascioliasis of cattle is studied.

Larval development of the stygobitic shrimp Creaseria morleyi (Creaser, 1936) (Decapoda: Caridea: Palaemonidae) from the Yucatán Peninsula, Mexico

2020 ◽  
Vol 40 (3) ◽  
pp. 221-229
Author(s):  
Sergio A Benítez ◽  
Thomas M Iliffe ◽  
Salvador Martínez ◽  
Juan Carlos Ojeda ◽  
José Luis Villalobos ◽  
...  
Keyword(s):  
Larval Development ◽  
Yucatan Peninsula ◽  
Juvenile Stage ◽  
Quintana Roo ◽  
Stages Of Development ◽  
Larval Stages ◽  
Yucatán Peninsula ◽  
Anchialine Caves

Abstract Although the larval development of epigean palaemonid shrimps has been studied extensively, only a few investigations deal with stygobitic species. We present the larval development of the cave-adapted Creaseria morleyi (Creaser, 1936) from anchialine caves in the Tulum area, Quintana Roo, Yucatán Peninsula, Mexico. Through the discovery of a series of larvae at different stages of development, we constructed a sequence extending through the juvenile stage. The larvae (41) were captured in plankton tows above the halocline at depths ranging between 11 and 15 m during eight surveys conducted between 2013 and 2016. Six larval stages and the first juvenile were identified; however, it is clear from the gradual modification of structures and appendages that more stages exist. The first larvae have a large quantity of vitellum and do not feed, since they have only rudimentary, and possibly non-functional, mouthparts. In the sixth stage and the juvenile, when the stages have no vitellum left, the mouthparts, chelae, and pleopods develop entirely. A comparison with other palaemonid shrimps suggests that C. morleyi has a greater affinity with those palaemonid species possessing extended larval development as is seen in species of MacrobrachiumSpence Bate, 1868.

The effects of Fasciola hepatica on Lymnaea truncatula

Parasitology ◽  
1972 ◽  
Vol 65 (2) ◽  
pp. 359-369 ◽  
Author(s):  
J. K. M. Hodasi
Keyword(s):  
Rapid Growth ◽  
Egg Production ◽  
Fasciola Hepatica ◽  
Age Groups ◽  
Sharp Decline ◽  
General Belief ◽  
Functional Changes ◽  
Complete Cessation ◽  
Lymnaea Truncatula ◽  
Accelerated Growth

Among the functional changes observed in L. truncatula infected with F. hepatica were those of growth, reproduction and mortality. For the first 3 weeks after infection there was no difference between the growth of infected and uninfected groups of snails. Thereafter there was a temporary accelerated growth which occurred between the fourth and seventh weeks after infection. The onset of this period of rapid growth in the different age groups of infected snails coincided with the time of migration of the rediae into the hepatopancreas. Of more significance was the influence of infection on the reproduction of the snail. There was a sharp decline in oviposition 2–3 weeks after infection, followed by a complete cessation of egg production at the end of the fifth week. Once oviposition ceased, it was not resumed and there was no self-cure. Contrary to general belief, infected groups of L. truncatula have been found to live longer than the uninfected controls. With isolated snails, however, there was a tendency for the uninfected snails to live longer than the infected ones. The possible interpretation of the discrepancies between isolated and mass cultured snails are discussed. The hepatopancreas and the gonad (ovotestis) were the two structures directly affected by the infection. Establishment of the rediae in the hepatopancreas invariably resulted in parasitic castration.

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