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.

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.

Parasite utilization of a host community: the distribution and occurrence of metacercarial cysts of Echinoparyphium recurvatum (Digenea: Echinostomatidae) in seven species of mollusc at Harting Pond, Sussex

Parasitology ◽  
1981 ◽  
Vol 83 (1) ◽  
pp. 1-12 ◽  
Author(s):  
N. A. Evans ◽  
P. J. Whitfield ◽  
A. P. Dobson
Keyword(s):  
Intermediate Host ◽  
Host Community ◽  
Population Estimates ◽  
Sphaerium Corneum ◽  
Mollusc Species ◽  
Second Intermediate Host ◽  
The Mean ◽  
Over Dispersion ◽  
First Intermediate Host ◽  
Potamopyrgus Jenkinsi

SUMMARYThe occurrence, in September 1979, of Echinoparyphium recurvatum metacercarial cysts in a community of molluscan hosts at Harting Pond, West Sussex, was investigated. The parasite exhibited broad host specificity with all 7 species comprising the molluscan community being infected. There were marked differences, however, in the extent to which each host species was utilized and using the mean number of parasites/ individual mollusc as a parameter of infection the mollusc species may be ranked in descending order of utilization as follows: Sphaerium corneum, Lymnaea peregra, Valvata piscinalis, planorbids, Pisidium subtruncatum and Potamopyrgus jenkinsi. Combination of basic infection data with population estimates for each mollusc species in the study area showed that the bivalve P. subtruncatum and the prosobranch V. piscinalis were the most important hosts because they contained approximately 90% of the total number of cysts. In both of these hosts the cyst population was over-dispersed and the degree of over-dispersion increased with host size. The pattern of second intermediate host utilization is discussed in relation to the likely flow of E. recurvatum between the first intermediate host (L. peregra) and wildfowl definitive hosts at Harting.

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.

STUDIES ON CESTODES OF THE GENUS TRIAENOPHORUS FROM FISH OF LESSER SLAVE LAKE, ALBERTA: IV. THE LIFE OF TRIAENOPHORUS CRASSUS FOREL IN THE SECOND INTERMEDIATE HOST

1945 ◽  
Vol 23d (4) ◽  
pp. 105-115 ◽  
Author(s):  
Richard B. Miller
Keyword(s):  
Intermediate Host ◽  
Lake Trout ◽  
Body Cavity ◽  
The Body ◽  
Coregonus Clupeaformis ◽  
Alternative Hosts ◽  
Pyloric Caeca ◽  
Drying Up ◽  
Second Intermediate Host

The plerocercoids of Triaenophorus crassus encyst normally in the flesh of fishes of the genus Leucichthys; the whitefishes, Coregonus clupeaformis and Prosopium oregonium, are common alternative hosts in Lesser Slave Lake. Elsewhere lake trout, Cristivomer namaycush, and possibly the inconnu, Stenodus leucichthys, may occasionally serve as hosts.The procercoids arrive in the stomach of their second intermediate host while in the body cavity of Cyclops bicuspidatus. When they are liberated by digestion, the majority apparently enter pyloric caeca, penetrate these, cross the body cavity, and enter the flesh, where encystment as the plerocercoid takes place. The evidence for these movements is only partial. The plerocercoids encyst in the flesh in July each year. They remain three or four years and then disappear by drying up or being reduced to small calcareous nodules.The number of plerocercoids per fish increases with the age of the fish up to five or six years.

One snail – three Digenea species, different strategies in host-parasite interaction

2011 ◽  
Vol 61 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Elżbieta Żbikowska
Keyword(s):  
Intermediate Host ◽  
Parasite Species ◽  
Lymnaea Stagnalis ◽  
Behavioral Changes ◽  
Diplostomum Pseudospathaceum ◽  
Second Intermediate Host ◽  
Host Parasite ◽  
The Impact ◽  
Plagiorchis Elegans ◽  
First Intermediate Host

AbstractThe mostly lab-based studies on snail-trematode interactions should be complemented by research on naturally invaded hosts. In this mini-review, three different ways of snail exploitation by Digenea larvae are presented. Morphological, physiological and behavioral changes caused by three parasites in the same naturally infected host – Lymnaea stagnalis – differ in species-dependent fashion. The impact of a snail-trematode interaction depends on parasite virulence (i.e. parasite induced lost of fitness of the host). The pathogenicity varies with the survival strategy of the invader. Sporocyst-born Plagiorchis elegans, which uses the same Lymnaea stagnalis individual as a first but also as a second intermediate host, does not disturb host processes as strongly as redia-born Echinoparyphium aconiatum. The third parasite species – Diplostomum pseudospathaceum, also sporocyst-born – is more virulent than P. elegans, but it can modify and relax host exploitation to overwinter in the snail. The data presented demonstrate that successful use of first intermediate host can be arranged in different ways.

The structure of the adult and larval stages of Plagiorchis (Multiglandularis) megalorchis n.nom. from the turkey and an experimental demonstration of the life history

Parasitology ◽  
1952 ◽  
Vol 42 (1-2) ◽  
pp. 92-113 ◽  
Author(s):  
Gwendolen Rees
Keyword(s):  
Intermediate Host ◽  
Wild Bird ◽  
Experimental Demonstration ◽  
Insect Larvae ◽  
Larval Stages ◽  
Turkey Poults ◽  
Large Numbers ◽  
Second Intermediate Host ◽  
Culicoides Nubeculosus ◽  
First Intermediate Host

1. Large numbers of Plagiorchis (M.) megalorchis n.nom. were found in the intestine of four turkey poults of a total of thirteen which had died on a farm in Radnorshire. Presumably the presence of the parasites was the cause of death.2. The anatomy of the adult worm is described.3. The first intermediate host of the parasite is Lymnaea pereger, and the second intermediate host any of the following species of insect larvae: Chironomus riparius Meigen, Culicoides stigma Meigen, Culicoides nubeculosus Meigen and Anatopynia (Psectrotanypus) varius Fabr.4. The larval stages of the worm are described.5. The life cycle has been demonstrated experimentally by the feeding of insect larvae containing encysted cercariae to turkey poults.6. The turkey is probably not the normal host of Plagiorchis (M.) megalorchis. It is most likely that it occurs naturally in some species of wild bird, but this is not yet known.

Studies on the life-cycle of Himasthla militaris(Trematoda: Echinostomatidae)

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 609-617 ◽  
Author(s):  
R. Vanoverschelde ◽  
F. Vaes
Keyword(s):  
Intermediate Host ◽  
The Body ◽  
Exogenous Factor ◽  
Specific Distribution ◽  
Temperature Environment ◽  
Second Intermediate Host ◽  
Anterior Segments ◽  
External Migration ◽  
First Intermediate Host ◽  
Cercarial Emergence

SUMMARYIn this study two aspects of the biology of the cercaria of Himasthla militaris were examined. Firstly, the cercarial emergence from the first intermediate host, Hydrobia stagnorum, was studied. On a 9 h light (9L)/15 h dark (15D) schedule cercariae of Himasthla militaris emerged from naturally infected Hydrobia stagnorum predominantly during darkness. Inversion of the photo-period resulted in an immediate reversal of the emergence pattern. A comparison between the cercarial release patterns under natural conditions and in a constant light/temperature environment showed that an endogenous as well as an exogenous factor is controlling this process. Secondly, the penetration of the cercaria in Nereis diversicolor and the site-finding of the larva within this second intermediate host was investigated. After a short external migration on the body of N. diversicolor the cercaria enters the polychaete via the anus opening, perforates the gut-wall and moves through the coelom to the anterior segments to encyst in the muscle tissue. This internal migration results in a specific distribution pattern of the metacercariae, with more than 50% of the cysts localized in the first 12 segments and a maximum in segment number 9 (13·8%).

Temporal variation of Meiogymnophallus minutus infections in the first and second intermediate host

2010 ◽  
Vol 84 (4) ◽  
pp. 362-368 ◽  
Author(s):  
J. Fermer ◽  
S.C. Culloty ◽  
T.C. Kelly ◽  
R.M. O'Riordan
Keyword(s):  
Temporal Variation ◽  
Intermediate Host ◽  
Seasonal Patterns ◽  
Intertidal Flat ◽  
Infection Rates ◽  
Intermediate Hosts ◽  
Cerastoderma Edule ◽  
Scrobicularia Plana ◽  
Second Intermediate Host ◽  
First Intermediate Host

AbstractIn order to study seasonal patterns of Meiogymnophallus minutus infections in its intermediate hosts, bivalve samples were collected monthly between April 2008 and March 2009 from a high intertidal flat at Courtmacsherry Bay, Ireland. Infection rates in the first intermediate host Scrobicularia plana did not fluctuate significantly with season. Completely developed M. minutus cercariae appeared in daughter sporocysts from June and prevailed from July to October, indicating that transmission of M. minutus from its first to its second intermediate host is confined to this period of the year. All analysed individuals of the second intermediate host Cerastoderma edule were found to be infected with metacercariae. Infection levels significantly increased in September, suggesting recent cercarial invasions. Throughout the year, the majority of metacercariae were hyperinfected by the pathogenic microsporidian Unikaryon legeri. Spreading of hyperinfections was confined to spring and summer. Newly settled metacercariae were not affected by hyperparasitism and presumably retained their infectivity for half a year. Our findings suggest that the spreading of hyperinfections is correlated with higher water temperatures and that the entire metacercarial population has to rebuild every year as a consequence of hyperparasite-induced mortality.

First molecular identification of Ascocotyle (Phagicola) longa in its first intermediate host the mud snail Heleobia australis

2015 ◽  
Vol 60 (4) ◽  
Author(s):  
Pilar Alda ◽  
Nicolás Bonel ◽  
Carlos J. Panei ◽  
Néstor J. Cazzaniga ◽  
Sergio R. Martorelli
Keyword(s):  
Intermediate Host ◽  
Bahía Blanca Estuary ◽  
Larval Stages ◽  
Mud Snail ◽  
Total Prevalence ◽  
Second Intermediate Host ◽  
Species Specific ◽  
Dna Primers ◽  
First Intermediate Host ◽  
Blanca Estuary

AbstractThis is the first study that used species-specific DNA primers to confirm the presence of the heterophyid Ascocotyle (Phagicola) longa Ransom, 1920 in its first intermediate host. The larval stages (rediae and cercariae) of this parasite were morphologically and genetically identified in the gonad of the intertidal mud snail Heleobia australis (d’Orbigny, 1835) (Cochliopidae) in the Bahía Blanca estuary, Argentina. In addition, we asked whether the prevalence in H. australis varied between seasons. Mullets - the second intermediate host of this heterophyid - migrate in estuaries during the warmer seasons and it is expected that piscivorous birds and mammals - the definitive hosts - prey more intensively on this species at those times. Thus, the number of parasite eggs released into the tidal flat within their feces should be higher, thereby increasing the ingestion of the parasite by H. australis.We therefore expected a higher prevalence of A. (P.) longa in H. australis in the Bahía Blanca estuary during spring and summer than autumn and winter. We found that 16 out of 2,744 specimens of H. australis had been infected with A. (P.) longa (total prevalence of 0.58%). Nonetheless, the prevalence showed no significant variation between seasons. Hence, we discuss an alternative scenario where the lack of seasonal changes might be mostly related to the permanent residence of definitive hosts in the estuary and not to the seasonal recruitment of mullets. Finally, we highlight the need for more experimental and comparative approaches in order to understand the diagnosis and geographical distribution of this worldwide heterophyid.

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