Non-random patterns of host use by the different parasite species exploiting a cockle population

Parasitology ◽  
2000 ◽  
Vol 121 (3) ◽  
pp. 289-295 ◽  
Author(s):  
R. POULIN ◽  
M. J. STEEPER ◽  
A. A. MILLER
Keyword(s):  
Life Cycle ◽  
Definitive Host ◽  
Parasite Species ◽  
Parasitic Copepod ◽  
Sediment Surface ◽  
Host Use ◽  
Shell Size ◽  
Digenean Species ◽  
Conflicting Interests ◽  
Random Patterns

Different parasite species sharing the same intermediate host species may have similar or conflicting interests, depending on whether they are at the same stage in their life-cycle or whether they share the same definitive host. In the New Zealand cockle, Austrovenus stutchburyi, metacercariae of the digenean Meiogymnophallus sp. are positively associated with metacercariae of Curtuteria australis. This relationship is found in different cockle samples, and is independent of cockle shell size, which suggests that it is not merely the product of metacercariae accumulation over time. Both digenean species have the same definitive host, oystercatchers. Metacercariae of C. australis manipulate the phenotype of cockles, impairing the cockle's ability to burrow in the sediments. This makes the host more susceptible to oystercatcher predation. Thus Meiogymnophallus sp. can benefit by associating with C. australis and may hitch a ride with the manipulator parasite. This is supported by the finding that cockles impaired by C. australis and lying at the sediment surface harbour greater numbers of Meiogymnophallus than buried cockles. A third digenean species, whose sporocysts are found in cockles and which is not transmitted by predation, occurred only in surface cockles. Finally, a parasitic copepod with a direct life-cycle was found evenly distributed among buried and surface cockles, independently of their metacercarial loads. These results show that different parasite species do not use cockles in a random fashion, and that not all patterns of host use are consistent with shared or conflicting interests among parasites.

A comparative study of the life-histories of mammalian schistosomes

Parasitology ◽  
1983 ◽  
Vol 87 (2) ◽  
pp. 343-369 ◽  
Author(s):  
Eric S. Loker
Keyword(s):  
Life Cycle ◽  
Adult Worm ◽  
Intermediate Host ◽  
Definitive Host ◽  
Life Histories ◽  
Egg Production ◽  
Patent Period ◽  
Shell Size ◽  
Progeny Size ◽  
Facultative Parthenogenesis

SUMMARYAvailable data in the literature pertaining to the life-history characteristics of all known species of mammalian schistosomes have been gathered, and correlations between such variables as length of pre-patent period, adult worm size, rate of progeny production and progeny size have been explored. Accommodation of the schistosome life-cycle to the constraints imposed by certain host characteristics such as life-expectancy and size is discussed. Of the 23 known species of mammalian schistosomes, 20 species apparently rely to a major extent on relatively large-bodied and long-lived mammals such as primates, ungulates and proboscideans for their transmission. Only 1 species,Schistosomatium douthitti, is exclusively dependent on rodents for its transmission.S. douthittiattains maturity within its definitive host faster than any other mammalian schistosome, and is the only species known to be capable of producing viable eggs by facultative parthenogenesis. For all species of mammalian schistosomes, adult worm size, as estimated by female length, is positively correlated with the number of uterine eggs contained within the female (r= 0·682). For the 7 species for which data exist, rate of egg production/worm pair/day is positively correlated with uterine egg counts (r= 0·873) and inversely correlated with egg length (r= −0·787) and miracidium length (r= −0·953). Length of the pre-patent period is positively correlated with egg length (r= 0·503). With respect to the molluscan host, the number of cercariae produced by snails is positively correlated with the shell size of the snail (r= 0·657). For the 5 species for which data exist, the rate of egg production is inversely correlated with shell size of the intermediate host (r= −0·955) and the common logarithm of the number of cercariae produced (r= −0·893). Comparisons between species suggest that exceptionally low rates of cercariae production in the intermediate host may be compensated for by rapid rates of egg production in the definitive host, implying a degree of integration in the schistosome life-cycle not previously appreciated. Most species of mammalian schistosomes have long-lived definitive hosts, and snail hosts capable of producing many cercariae; compensatory relationships are therefore less obvious in such species. Additional quantitative data on all aspects of schistosome life-histories, particularly rate and duration of egg production, are needed to confirm or refute the relationships discussed above.

Checklist of digenean parasites of amphibians and reptiles from Argentina

Zootaxa ◽  
2007 ◽  
Vol 1476 (1) ◽  
pp. 51 ◽  
Author(s):  
LÍA I. LUNASCHI ◽  
FABIANA B. DRAGO
Keyword(s):  
New Species ◽  
Life Cycle ◽  
Geographical Distribution ◽  
Native Species ◽  
Parasite Species ◽  
Present Review ◽  
Digenean Species ◽  
Host Parasite

A summary of the literature on the digeneans of amphibians and reptiles in Argentina is presented. This is the first compilation of 32 parasitological papers published from 1940 through 2006. This review includes 49 native species (11 frogs, 1 toad, 33 snakes, 2 turtles, 1 lizard and 1 crocodilian) and contains 42 species of adult digeneans belonging to 24 genera and 14 families as well as 5 genera of larval digeneans (metacercariae). Twenty-eight digenean species have been reported from reptiles and 14 from amphibians, of which 6 species (14.3%) were recorded as new species. The present review provides data on hosts, geographical distribution, site of infection, life cycle, the location of material deposited in Helminthological Collections and references for the parasite species arranged by Superfamilies. A host/parasite list is also provided.

Taeniasis in a German Shepherd Pup: A Case Report

2019 ◽  
Vol 15 (01) ◽  
pp. 83-84
Author(s):  
B J Thakre ◽  
Joice P Joseph ◽  
Binod Kumar ◽  
Nilima Brahmbhatt ◽  
Krishna Gamit
Keyword(s):  
Case Report ◽  
Life Cycle ◽  
Definitive Host ◽  
Gastrointestinal Diseases ◽  
Intermediate Hosts ◽  
German Shepherd ◽  
Taenia Hydatigena ◽  
Taenia Multiceps ◽  
Taenia Crassiceps ◽  
Dipylidium Caninum

Taenia spp. are long, segmented, parasitic tapeworms and are relatively uncommon in canine gastrointestinal diseases compared to other tapeworms like Dipylidium caninum. These parasites have an indirect life cycle, cycling between definitive and intermediate hosts. Dogs act as definitive hosts of different species of Taenia including Taenia multiceps, Taenia serialis, Taenia crassiceps, Taenia hydatigena, Taenia pisiformis, etc. Taenia multiceps is of greatest zoonotic relevance in human. In the definitive host, it causes only mild infection. Larvae are more likely to cause disease than adult tapeworms. Taeniasis in pets should be cautiously handled because of its zoonotic importance. This communication reports a case of 3 months old pup suffering from Taenia infection that was successfully managed with a combination of praziquantel and fenbendazole.

The developmental stages of Neobrachiella robusta (Wilson, 1912), a parasitic copepod of Sebastes (Teleostei: Scorpaeniformes)

1987 ◽  
Vol 65 (6) ◽  
pp. 1331-1336
Author(s):  
Z. Kabata
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Parasitic Copepod ◽  
Gill Arch ◽  
Gill Rakers ◽  
Copepodid Stage

The morphology of the developmental stages of Neobrachiella robusta (Wilson, 1912) (Copepoda: Siphonostomatoida) is described. The copepod is parasitic on the gill rakers of Sebastes alutus (Gilbert, 1890) (Teleostei: Scorpaeniformes). The life cycle of this copepod consists of a copepodid stage, followed by four chalimus stages and a relatively long preadult stage, which undergoes extensive metamorphosis. The copepods aggregate on the outer row of long gill rakers of the first gill arch, as many as 97% of them being attached to these rakers. Some of the rakers become distorted, but a connection between the presence of N. robusta and these abnormalities could not be established.

Speciation of cestoda. Evidence for two sibling species in the complex Bothrimonus nylandicus (Schneider 1902) (Cestoda: Cyathocephalidea)

Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 139-147 ◽  
Author(s):  
F. Renaud ◽  
C. Gabrion
Keyword(s):  
Sibling Species ◽  
Definitive Host ◽  
Parasite Species ◽  
Adult Stage ◽  
Life Cycles ◽  
The Other ◽  
Congeneric Species ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
Biological Differences

SUMMARYUsing biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.

scholarly journals Contrasting associations between breeding coloration and parasitism of male Arctic charr relate to parasite species and life cycle stage

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
I. B. Johansen ◽  
E. H. Henriksen ◽  
J. C. Shaw ◽  
I. Mayer ◽  
P.-A. Amundsen ◽  
...  
Keyword(s):  
Life Cycle ◽  
Parasite Species ◽  
Arctic Charr ◽  
Life Cycle Stage ◽  
Breeding Coloration

Comparative migration, growth and development of Typhlocoelum cucumerinum sisowi in dabbling ducks and Typhlocoelum cucumerinum cucumerinum in diving ducks

Parasitology ◽  
1982 ◽  
Vol 84 (2) ◽  
pp. 333-350 ◽  
Author(s):  
Marilyn E. Scott ◽  
M. E. Rau ◽  
J. D. McLaughlin
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Definitive Host ◽  
Host Species ◽  
Growth And Development ◽  
Abdominal Cavity ◽  
Dabbling Ducks ◽  
Diving Ducks ◽  
Air Sacs ◽  
Aythya Valisineria

SUMMARYExperimental infections of mallards (Anas platyrhynchos L.) with Typhlocoelum cucumerinum sisowi (Skrjabin, 1913) and of canvasbacks (Aythya valisineria (Wilson)) with Typhlocoelum cucumerinum cucumerinum (Rudolphi, 1809) revealed significant differences in various parameters of the life-cycle in the definitive host. Both T. c. sisowi and T. c. cucumerinum migrate to the trachea via the abdominal cavity, air sacs and lungs, although T. c. cucumerinum migrate more quickly and more synchronously than T. c. sisowi. Typhlocoelum c. sisowi has a shorter expected life-span than T. c. cucumerinum but grows and reaches maturity more quickly than T. c. cucumerinum. Evidence suggests that T. c. cucumerinum has a higher fecundity than T. c. sisowi. These differences in the patterns of migration, growth and development are related not only to differences between the two host species but also to differences intrinsic to the parasites, and serve to provide biological support for considering them as separate sub-species.

Some Observations on the Transmission of Bacteria by Infective Larvae of Nippostrongylus brasiliensis

1955 ◽  
Vol 29 (1-2) ◽  
pp. 27-32 ◽  
Author(s):  
H. M. Gharib
Keyword(s):  
Life Cycle ◽  
Definitive Host ◽  
Infected Host ◽  
Nippostrongylus Brasiliensis ◽  
Infective Stage ◽  
Natural Conditions ◽  
Larval Stages ◽  
Infective Larvae ◽  
External Development

It is well known that the first two larval stages in the life cycle of nematodes belonging to the superfamily Strongloidea, have a freeliving existence. During this time, the larva which hatches from the egg feeds actively, undergoes two moults and grows considerably before reaching the infective stage, when it is ready to invade a definitive host. Under natural conditions this external development takes place in the faeces, which have been deposited by the infected host on ground likely to be contaminated with various bacteria.

A review of the infectious agents, parasites, pathogens and commensals of European cockles (Cerastoderma eduleandC. glaucum)

2012 ◽  
Vol 93 (1) ◽  
pp. 227-247 ◽  
Author(s):  
Matt Longshaw ◽  
Shelagh K. Malham
Keyword(s):  
Systematic Review ◽  
Life Cycle ◽  
Parasite Species ◽  
Future Research ◽  
Infectious Agents ◽  
Cerastoderma Edule ◽  
Cerastoderma Glaucum ◽  
Burrowing Behaviour ◽  
The Individual ◽  
Population Effects

A systematic review of the parasites, pathogens and commensals of the edible cockle (Cerastoderma edule) and of the lagoon cockle (Cerastoderma glaucum) has been completed. A total of 59 different conditions have been reported throughout the range of both of these hosts; of these 50 have been reported in edible cockles, and 28 in lagoon cockles. Cockles are hosts to viruses, bacteria, fungi (including Microsporidia), Apicomplexa, Amoeba, Ciliophora, Perkinsozoa, Haplosporidia, Cercozoa, Turbellaria, Digenea, Cestoda, Nematoda, Crustacea and Nemertea. A number of these have been reported sporadically although they may be associated with mortalities. In particular, mortalities have been associated predominately with digeneans and some protistan infections. In many cases pathology is marked in affected animals and parasites have been shown to reduce fecundity, alter burrowing behaviour and limit growth. This review provides information on the individual and population effects of these conditions as well as providing suggestions for future research. In particular, there has been a lack of taxonomic rigour applied to many studies and as a result there are a number of erroneous host records. There is a need to re-describe a number of parasite species and to determine the life cycle of those considered to be important mortality drivers.

Transmission dynamics of Echinococcus multilocularis; its reproduction number, persistence in an area of low rodent prevalence, and effectiveness of control

Parasitology ◽  
2005 ◽  
Vol 131 (1) ◽  
pp. 133-140 ◽  
Author(s):  
K. TAKUMI ◽  
J. VAN DER GIESSEN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Central Europe ◽  
Definitive Host ◽  
Echinococcus Multilocularis ◽  
Reproduction Number ◽  
Parasite Burden ◽  
Host Population ◽  
Total Biomass ◽  
Control Campaign

On the basis of high prevalences of Echinococcus multilocularis in the growing fox populations in Central Europe, its total biomass may have increased significantly in the past 20 years. E. multilocularis is now also found in areas outside the known endemic area in Central Europe. Therefore, E. multilocularis, the causative agent of a serious parasitic zoonosis, might be of major concern for public health and a challenge to control. Some experimental field trials to control E. multilocularis using an anti-worm drug reduced parasite burden in a contaminated region during the control campaign, but failed to eradicate the parasite completely. It was our aim to develop a mathematical model describing the biomass of egg, larval, and adult worm stages of the E. multilocularis life-cycle, and simulate a hypothetical control campaign. Additionally, we derived the reproduction number of this parasite and explored conditions for the persistence of the parasite's life-cycle. Our model shows that while control campaigns rapidly reduce the worm burden in the definitive host, and consequently eggs in the environment, the pool of larvae in the intermediate host remains large. The parasite's life-cycle persists in a region where prevalence in the intermediate host is low (∼1%). Therefore, we conclude that the parasite is likely to re-emerge if control is discontinued on the basis of reduced worm population. Continued treatment of the definitive host is required to eradicate the larval stage of the parasite from the intermediate host population.

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