Evaluating the Biological and Ecological Factors Influencing Transmission of Larval Digenetic Trematodes: A Test of Second Intermediate Host Specificity of Two North AmericanHalipegusSpecies

2016 ◽  
Vol 102 (6) ◽  
pp. 613-621 ◽  
Author(s):  
Heather A. Stigge ◽  
Matthew G. Bolek
Keyword(s):  
Intermediate Host ◽  
Host Specificity ◽  
Ecological Factors ◽  
Factors Influencing ◽  
Digenetic Trematodes ◽  
Second Intermediate Host

SOME MICRO-ECOLOGICAL FACTORS INFLUENCING THE POPULATION DYNAMICS OF SCHISTOSOMIASIS INTERMEDIATE HOST SNAILS IN KHARTOUM STATE, SUDA

2016 ◽  
Vol 4 (8) ◽  
pp. 147-151
Author(s):  
A. Zakaria Mohamed ◽  
Azzam Afifi ◽  
Yassir Sulieman ◽  
Theerakamol Pengsakul
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Growth ◽  
Intermediate Host ◽  
Population Growth Rate ◽  
Ecological Factors ◽  
Water Bodies ◽  
Snail Population ◽  
Factors Influencing ◽  
High Turbidity

This study was conducted to determine the role of some micro-ecological factors influencing the population dynamics of schistosomiasis intermediate host snails in the water bodies of Khartoum State, Sudan. The results show that the air and water temperature play a significant role in the determination of snail growth, a gradual increase of air and water temperate causing an increase in the snail population growth rate with the peak in summer. Water of high turbidity and high current speed caused a drop in the snail population. Vegetation cover in water bodies showed a significant effect on the snail population, the denser the cover the higher the snail population growth rate.

Development and infectivity of the procercoid of Triaenophorus crassus Forel and mortality of the first intermediate host

1983 ◽  
Vol 61 (9) ◽  
pp. 2120-2128 ◽  
Author(s):  
R. Rosen ◽  
T. A. Dick
Keyword(s):  
Intermediate Host ◽  
Negative Binomial ◽  
Coregonus Clupeaformis ◽  
Factors Influencing ◽  
Percent Recovery ◽  
Second Intermediate Host ◽  
The Mean ◽  
Coregonus Artedii ◽  
First Intermediate Host ◽  
Over Time

Mortality of Cyclops bicuspidatus thomasi infected with the procercoid of Triaenophorus crassus was assessed and factors influencing the infectivity of the procercoid to the second intermediate host were evaluated. Over 80% of C. b. thomasi infected with T. crassus died after 28 days, and there was a bimodal pattern to cyclopid mortality. A decrease in the mean intensity over time indicated that this mortality was related to parasite numbers. The frequency of T. crassus in C. b. thomasi after 28 days fitted the negative binomial distribution. A higher proportion of lightly infected cyclopids at this time resulted from mortality of heavily infected hosts. Female cyclopids had larger procercoids than males, but the ratio of differentiated to undifferentiated procercoids did not vary between sexes. Procercoid size was smaller and the proportion of differentiated procercoids decreased with increasing intensities of infection. Exposure of laboratory-reared whitefish, Coregonus clupeaformis, and cisco, Coregonus artedii, to procercoids from crowded infections resulted in a low percent recovery of plerocercoids, while less crowded infections of procercoids produced a high percent recovery of plerocercoids in fish. The number of procercoids to which fish were exposed affected the percent recovery of plerocercoids.

The life-cycle of Bucephaloides gracilescens (Rudolphi, 1819) Hopkins, 1954 (Digenea: Gasterostomata)

Parasitology ◽  
1974 ◽  
Vol 68 (1) ◽  
pp. 1-12 ◽  
Author(s):  
R. A. Matthews
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Host Specificity ◽  
Comparative Morphology ◽  
Rock Pools ◽  
Second Intermediate Host ◽  
High Degree ◽  
First Time ◽  
First Intermediate Host

The cercaria and sporocyst of Bucephaloides gracilescens are described from Abra alba (Wood). Observations were made on the behaviour of the cercaria and the mechanism of release from the first intermediate host. The metacercaria was obtained experimentally for the first time using Ciliata mustela (L.), a species of Gadidae from rock pools, as second intermediate host. It has not previously been recorded from this fish. Unsuccessful attempts were made to infect species of fishes from three other families, namely, Bothidae, Pleuronectidae and Gobiidae, confirming the high degree of host specificity of the metacercaria to Gadidae. The metacercaria, its development and effect on the host are briefly discussed. It was linked with the adult on the basis of comparative morphology and ecology of the hosts.

scholarly journals The Effect of Trematode Parasites on the Growth of Littorina Neritoides (L.)

1941 ◽  
Vol 25 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Miriam Rothschild
Keyword(s):  
Intermediate Host ◽  
Large Size ◽  
Size Groups ◽  
Second Intermediate Host ◽  
Upward Slope ◽  
Accelerated Growth ◽  
The Difference ◽  
First Intermediate Host ◽  
Low Rate ◽  
Trematode Parasites

If the number of infections with (a) trematode parthenitae and cercariae using Littorina neritoides as first intermediate host only, and (b) encysted metacercariae using L. neritoides as second intermediate host only, are plotted against the size of the snails, two different curves result. The first shows a low rate of infection in the small size groups, but a steep upward slope rising to 91% in the large size groups. The second shows a curve increasing uniformly to 87% infection.Possible interpretations are discussed, and it is concluded that the difference is probably due to the fact that primary infections cause accelerated growth in the host.

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