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.

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.

Metazoan parasites in an intermediate host population near its southern border: the common cockle (Cerastoderma edule) and its trematodes in a Moroccan coastal lagoon (Merja Zerga)

2008 ◽  
Vol 88 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Mériame Gam ◽  
Hocein Bazaïri ◽  
K. Thomas Jensen ◽  
Xavier de Montaudouin
Keyword(s):  
Species Composition ◽  
Intermediate Host ◽  
Coastal Lagoon ◽  
Life Cycles ◽  
Geographical Range ◽  
Trematode Species ◽  
Intermediate Hosts ◽  
Metazoan Parasites ◽  
Cerastoderma Edule ◽  
Second Intermediate Host

The metazoan parasite community of Cerastoderma edule was studied in the southern geographical range of the host (the coastal lagoon Merja Zerga, Morocco). A total of 11 metazoan species was found in cockles. Nine of these were trematodes using cockles as either first intermediate host (three species) or second intermediate host (six species). In addition, two other endo-metazoan species (Pinnotheres pisum and Paravortex cardii) were recorded from cockles in the studied lagoon. All the observed metazoans in cockles from Merja Zerga have previously been recorded at sites north of Africa.Up to 10% of the cockles in the studied size-groups were first intermediate hosts to castrating parasites (Gymnophallus choledochus, Labratrema minimus and Monorchis parvus). Among trematodes having metacercariae in cockles (second intermediate host) Meiogymnophallus minutus was the most widespread as it was observed in all cockles from all the examined habitats in the lagoon and it occurred in record high intensities. Different sub-communities of the trematode fauna using cockles as second intermediate host could be identified (subtidal vs intertidal associations).The richness and species composition of the macroparasite community in cockles from Morocco are discussed in relation to patterns seen in cockles from other sites along their geographical range. Migratory fish and waterbirds (final hosts) are generally responsible for the large scale spread (latitudinal spread) of trematodes. However, the distributional patterns of involved intermediate hosts in the life-cycles of the different trematode species in cockles are determining the richness and species composition patterns seen in cockles at shallow water sites along the east Atlantic shoreline.

Evidence of an altered protective effect of metallothioneins after cadmium exposure in the digenean parasite-infected cockle (Cerastoderma edule)

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 237-245 ◽  
Author(s):  
M. BAUDRIMONT ◽  
X. de MONTAUDOUIN
Keyword(s):  
Protective Effect ◽  
Intermediate Host ◽  
Healthy Individuals ◽  
Experimental Exposure ◽  
Cd Accumulation ◽  
Cerastoderma Edule ◽  
Digenean Species ◽  
Second Intermediate Host ◽  
Cd Exposure ◽  
First Intermediate Host

The aim of the present study was to analyse the relation between parasitism and subsequent metallothioneins (MT) in the case of metal contamination. Experimental exposure of parasitized and unparasitized cockles (Cerastoderma edule) to cadmium (Cd) was performed, with the cockle as first or second intermediate host of 2 digenean species. After 7 days of Cd exposure in microcosms, cockles infected as first intermediate host byLabratrema minimusexhibited metal concentrations in tissues double that in uninfected cockles. Jointly, MT concentrations of parasitized cockles were not modified in comparison with uninfected individuals in which concentrations were increased 4·3-fold compared with controls. In cockles experimentally infected as the second intermediate host byHimasthla elongata, cadmium concentrations significantly increased again in parasitized cockles compared with uninfected individuals in contaminated conditions. Simultaneously, MT concentrations in healthy cockles increased, whereas they significantly decreased in parasitized individuals. Therefore, the presence of digenean parasites in Cd-exposed cockles leads to a maintenance or a decrease in MT concentrations compared with healthy individuals, whereas Cd accumulation in tissues is significantly increased. These experiments indicate a significant alteration of the protective effect of metallothioneins towards metals which could consequently enhance cockle vulnerability. Moreover, these results highlight the limit of the use of MT as a biomarker of metal pollution in field monitoring if parasitism is not taken into account.

Digenean metacercariae (Timoniellaspp.,Labratrema minimusandCryptocotyle concava) from the flounder,platichthys flesus, in the tidal Thames

1999 ◽  
Vol 73 (2) ◽  
pp. 103-113 ◽  
Author(s):  
H.E.M. El-Darsh ◽  
P.J. Whitfield
Keyword(s):  
Intermediate Host ◽  
Detailed Examination ◽  
Nursery Ground ◽  
Intermediate Hosts ◽  
Thames Estuary ◽  
Platichthys Flesus ◽  
Second Intermediate Host ◽  
Temporal And Spatial Characteristics ◽  
First Time ◽  
First Intermediate Host

A detailed examination of the abundant flatfish speciesPlatichthys flesus, the flounder, in the tidal Thames has revealed the presence of four digenean metacercarial parasites,Cryptocotyle concava(Creplin, 1825),Timoniella imbutiforme(Molin, 1859),T. praeterita(Looss, 1901) andLabratrema minimus(Stossich, 1887). Flounders were recorded as a new second intermediate host forT. praeteritaandL. minimus. They were also recorded as second intermediate hosts for the first time in British waters forT. imbutiforme. The temporal and spatial characteristics of these infections were examined and were believed to provide indirect parasitological evidence of the movement patterns of flounders during their utilization of the Thames Estuary as a nursery ground. From these data it was also surmised that the first intermediate host ofT. imbutiforme,T. praeteritaandC. concavawas probably the molluscan speciesHydrobia ulvaein the lower Thames Estuary, whereasL. minimuswas most likely to occur in the molluscan hostCerastoderma edule, also present in the lower estuary.

The Life Cycle and Biology of Opecoelus Variabilis, Sp.nov. (Digenea: Opecoelidae).

1985 ◽  
Vol 33 (5) ◽  
pp. 715 ◽  
Author(s):  
TH Cribb
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Intermediate Hosts ◽  
Full Size ◽  
Second Intermediate Host ◽  
New Diagnosis ◽  
Australian Freshwater ◽  
Further Development ◽  
First Intermediate Host ◽  
Prosobranch Snail

Opecoelus variabilis, sp. nov., is described from the intestine of 17 species of Australian freshwater fish. The highly variable anatomy of this species highlights the closeness of Opecoelus and Opegaster. Opegaster is made a synonym of Opecoelus and a new diagnosis is proposed for Opecoelus. The first intermediate host of O. variabilis is the prosobranch snail Posticobia brazieri, and the second intermediate hosts are five species of atyid, palaemonid and parastacid Crustacea. Features of the life cycle are the production of daughter sporocysts by the mother sporocyst when only one-quarter of its full size, and the further development of the metacercaria in the second intermediate host after becoming infective to the definitive host.

scholarly journals Do three-spined sticklebacks avoid consuming copepods, the first intermediate host ofSchistocephalus solidus? — an experimental analysis of behavioural resistance

Parasitology ◽  
1996 ◽  
Vol 112 (4) ◽  
pp. 371-383 ◽  
Author(s):  
C. Wedekind ◽  
M. Milinski
Keyword(s):  
Intermediate Host ◽  
Gasterosteus Aculeatus ◽  
Alternative Prey ◽  
Intermediate Hosts ◽  
Predator Prey ◽  
High Prevalence ◽  
Behavioural Resistance ◽  
Prey Interaction ◽  
Second Intermediate Host ◽  
First Intermediate Host

SUMMARYMany parasites that use intermediate hosts are transmitted to the next host through predation. If the next host's fitness is strongly reduced by the parasite, it is under selection either to recognize and avoid infected intermediate hosts or to exclude that prey species from its diet when alternative prey are available. We investigated the predator-prey interaction between laboratory bred three-spined sticklebacks (Gasterosteus aculeatus), the second intermediate host of the cestodeSchistocephalus solidus, from 2 parasitized and 1 unparasitized population, and different prey types: infected and uninfected copepods and size-matchedDaphniaas alternative prey. Copepods with infective procercoids were more active, had a lower swimming ability and were easier to catch than uninfected controls. The sticklebacks preferred moving copepods. Therefore parasitized copepods were preferentially attacked and consumed. There was no effect of the sticklebacks' parent population being parasitized or not. The sticklebacks switched fromDaphniato (uninfected) copepods in the course of a hunting sequence; this switch occurred earlier in smaller fish. With this strategy the fish maximized their feeding rate:Daphniawere easier to catch than copepods but increasingly difficult to swallow when the stomach was filling up especially for smaller fish. However, there was no indication that sticklebacks from infected populations either consumedDaphniarather than copepods or switched later in the hunting sequence to consuming copepods than fish from an uninfected population. Thus, sticklebacks did not avoid parasitized prey althoughS. solidususually has a high prevalence and causes a strong fitness reduction in its stickleback host.

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.

The influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum

1999 ◽  
Vol 73 (2) ◽  
pp. 143-145 ◽  
Author(s):  
A.M. McCarthy
Keyword(s):  
Intermediate Host ◽  
Definitive Host ◽  
Host Species ◽  
Post Infection ◽  
Rana Temporaria ◽  
Biomphalaria Glabrata ◽  
Reproductive Status ◽  
Intermediate Hosts ◽  
Potential Influence ◽  
Second Intermediate Host

The potential influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum to the definitive host Anas platyrhynchos was examined experimentally. Echinoparyphium recurvatum metacercarial cysts were obtained from the following experimentally infected second intermediate hosts 14 days post expsoure to cercariae: Lymnaea peregra; Physa fontinalis; L. stagnalis;Planorbis planorbis; Biomphalaria glabrata; tadpoles of the amphibian Rana temporaria. Metacercarial cysts from each of these hosts were fed, in doses of 50 cysts per individual, to separate groups composed of between four and eight, 3-day-old A. platyrhynchos ducklings. All A. platyrhynchos were necropsied 15 days post-infection and the number, size, and reproductive status of E. recurvatum worms in the intestine was recorded. Analyses of variance on the number (transformed log (x + 1)) and size of worms revealed no significant differences in worms originating from metacercariae formed in the different second intermediate hosts (worm number P > 0.05, and worm size P > 0.05). All worms recovered were found to be gravid. It is therefore concluded that the species of second intermediate host utilized does not influence the infectivity of the metacercarial cyst of E. recurvatum, nor the subsequent establishment and reproductive status of the parasite in A. platyrhynchos.

Observations on the field transmission dynamics of Schistosoma mansoni and S. mattheei in southern Natal, South Africa

Parasitology ◽  
1985 ◽  
Vol 91 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Fiona A. Donnelly ◽  
C. C. Appleton
Keyword(s):  
South Africa ◽  
Schistosoma Mansoni ◽  
Transmission Dynamics ◽  
Small Rivers ◽  
Seasonal Patterns ◽  
Infection Rates ◽  
Intermediate Hosts ◽  
Low Oxygen ◽  
Transmission Season ◽  
Extensive Growth

Cercarial transmission of Schistosoma mansoni and S. mattheei was monitored in two small rivers near Durban, South Africa. The seasonal patterns recorded corresponded to those already documented for these parasites. Tn the case of S. mansoni, however, this was interrupted at the height of the transmission season. The reason for this was believed to be very low oxygen concentrations in the snail habitat due to unusually extensive growth of the plant Ludwigia stolonifera over the water. The failure of the spring rains, which would normally have flushed the system is seen as contributing to this phenomenon. Infection rates in the snail intermediate hosts were low ( > 10%). A preponderance of male worms of both schistosome species was noted.

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