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.

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.

THE MORPHOLOGY, TAXONOMY, AND LIFE HISTORY OF METORCHIS CONJUNCTUS (COBBOLD, 1860)

1944 ◽  
Vol 22d (1) ◽  
pp. 6-16 ◽  
Author(s):  
Thomas W. M. Cameron
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Intermediate Host ◽  
Larval Stages ◽  
History Of ◽  
Second Intermediate Host ◽  
The Common ◽  
First Intermediate Host

A trematode, widely distributed in Canada, and occurring in man and other fish-eating mammals, is described and its taxonomy discussed. Its life cycle has been worked out and it is shown to involve a snail, Amnicola limosa porata as first intermediate host and a fish, the common sucker (Catostomus commersonii) as the second intermediate host. The larval stages are described.

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.

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.

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.

scholarly journals Potamopyrgus antipodarum (Gray, 1843) in Polish waters − its mitochondrial haplotype and role as intermediate host for trematodes

2020 ◽  
pp. 48
Author(s):  
Anna Stanicka ◽  
Kamila Stefania Zając ◽  
Dorota Lachowska-Cierlik ◽  
Anna Cichy ◽  
Janusz Żbikowski ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Potamopyrgus Antipodarum ◽  
Mitochondrial Haplotype ◽  
Main Role ◽  
Larval Stages ◽  
Mitochondrial Haplotypes ◽  
Second Intermediate Host ◽  
Haplotype 1 ◽  
New Zealand Mud Snail

The New Zealand mud snail (Potamopyrgus antipodarum (Gray, 1843)) is on the list of one hundred worst invasive species. Researchers point out that genetic variation between populations of P. antipodarum manifested in differences in life-history traits. The main objective of our investigation was to gain pioneer knowledge about mitochondrial haplotypes of P. antipodarum in Polish waters on the background of these haplotypes recorded in the world and confirmation of the main role of P. antipodarum in the life cycle of digenean trematodes. We examined 1000 individuals of P. antipodarum from five water bodies in three different parts of Poland for the presence of larval stages of digenean trematodes. For several randomly selected individuals we carried out DNA sequencing of the 16S ribosomal RNA gene as marker of this non-indigenous mollusk. Only one 16S rRNA haplotype of P. antipodarum was recorded in Polish waters, defined in this study as haplotype 1 which turned out to be the most widespread in Europe. Potamopyrgus antipodarum is a source of trematode metacercariae belonging mainly to the family Echinostomatidae. As a result, we can demonstrate that it plays a role as the second intermediate host of digenean trematodes in European waters.

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%).

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.

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