Solo Schistocephalus solidus tapeworms are nasty

Parasitology ◽  
2016 ◽  
Vol 143 (10) ◽  
pp. 1301-1309 ◽  
Author(s):  
JARLE TRYTI NORDEIDE ◽  
FELIPE MATOS
Keyword(s):  
Intermediate Host ◽  
Body Condition ◽  
Gasterosteus Aculeatus ◽  
Multiple Infections ◽  
High Latitudes ◽  
Trade Off ◽  
Host Condition ◽  
Schistocephalus Solidus ◽  
Dead End ◽  
Individual Host

SUMMARYTrophically transmitted parasites must trade-off own growth on one hand and energy drain from the intermediate host on the other hand, since killing the host before transmission to the next host is a dead end for both parasites and hosts. This challenge becomes especially intriguing when multiple parasites find themselves within the same individual host. The tapeworm Schistocephalus solidus may gain more than 98% of its final body mass within few months infecting its three-spined stickleback (Gasterosteus aculeatus) intermediate host. During these months the tapeworms may achieve a mass even larger than its host. We studied virulence of single and multiple infections of S. solidus, by comparing body condition of wild stickleback hosts in two perennial stickleback populations located at high latitudes, and each population was studied in two different years. Our results demonstrated multiple compared with single infections to be a highly significant predictor of the condition of stickleback hosts, with multiple-infected hosts having relatively higher body condition. However, this applied only after adjusting for parasite mass, which was another significant predictor for host condition. Thus, our results suggested that, at a given parasite mass, S. solidus was more harmful towards their host's body condition in single compared with multiple infections.

Are solo infections of the diphyllobothriidean cestode Schistocephalus solidus more virulent than multiple infections?

Parasitology ◽  
2018 ◽  
Vol 146 (1) ◽  
pp. 97-104 ◽  
Author(s):  
David C. Heins ◽  
Kristine N. Moody ◽  
Sophia Miller
Keyword(s):  
Body Condition ◽  
Gasterosteus Aculeatus ◽  
Resource Constraints ◽  
Negative Impact ◽  
Life History Strategy ◽  
The Body ◽  
Multiple Infections ◽  
Intermediate Hosts ◽  
Schistocephalus Solidus ◽  
The Impact

AbstractWe performed a long-term natural experiment investigating the impact of the diphyllobotriidean cestode Schistocephalus solidus on the body condition and clutch size (CS) of threespine stickleback Gasterosteus aculeatus, its second intermediate host, and the growth of larval parasites in host fish. We tested the hypothesis that single S. solidus infections were more virulent than multiple infections. We also asked whether the metrics of mean and total parasite mass (proxies for individual and total volume, respectively) were consistent with predictions of the resource constraints or the life history strategy (LHS) hypothesis for the growth of, hence exploitation by, larval helminths in intermediate hosts. The samples were drawn from Walby Lake, Alaska in eight of 11 years. Host body condition and CS (egg number per spawning bout) decreased significantly with intensity after adjustments for host size and parasite index. Thus, infections have an increasingly negative impact on measures of host fitness with greater intensity, in contrast to the hypothesis that single infections are more harmful than multiple infections. We also found that mean parasite mass decreased with intensity while total parasite mass increased with intensity as predicted by the LHS hypothesis.

The consequences of self-fertilization and outcrossing of the cestode Schistocephalus solidus in its second intermediate host

Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 369-378 ◽  
Author(s):  
M. CHRISTEN ◽  
M. MILINSKI
Keyword(s):  
Intermediate Host ◽  
Gasterosteus Aculeatus ◽  
Life Stage ◽  
Life History Strategy ◽  
Body Cavity ◽  
Infected Fish ◽  
Mixed Mating ◽  
Schistocephalus Solidus ◽  
Self Fertilization ◽  
Second Intermediate Host

Many hermaphroditic parasites reproduce by both cross-fertilization and self-fertilization. To understand the maintenance of such mixed mating systems it is necessary to compare the fitness consequences of the two reproductive modes. This has, however, almost never been done in the context of host–parasite coevolution. Here we show the consequences of outcrossing and selfing in an advanced life-stage of the cestode Schistocephalus solidus, i.e. in its second intermediate host, the three-spined stickleback (Gasterosteus aculeatus). Each juvenile stickleback was simultaneously exposed to 2 experimentally infected copepods, one harbouring outcrossed the other selfed parasites. At 60 days p.i. parasites were removed from the fish's body cavity and, with microsatellite markers, assigned to either outcrossed or selfed origin. Prevalence was not significantly higher in outcrossed parasites. However, those fish that were infected contained significantly more outcrossed than selfed parasites. Thus the probability of a selfed parasite to progress in the life-cycle is reduced in the second intermediate host. Furthermore, we found that even the multiply infected fish increased in weight during the experiment. Nevertheless, total worm weight in multiply infected fish was significantly lower than in singly infected ones, which thus might be a parasite life-history strategy.

Infections of the three-spined stickleback, Gasterosteus aculeatus L., with the plerocercoid larvae of Schistocephalus solidus (Müller, 1776), with special reference to pathological effects

Parasitology ◽  
1967 ◽  
Vol 57 (2) ◽  
pp. 301-314 ◽  
Author(s):  
C. Arme ◽  
R. Wynne Owen
Keyword(s):  
Gasterosteus Aculeatus ◽  
Science Research ◽  
Liver Weight ◽  
Infected Fish ◽  
The Body ◽  
Schistocephalus Solidus ◽  
Maximum Value ◽  
Individual Host ◽  
Concurrent Infections ◽  
The Relationship

Infections are described of Gasterosteus aculeatus in a pond at Leeds with the plerocercoid larvae of Schistocephalus solidus.Very heavy infections were found in the summer of 1962 and early 1963; many fish harboured over 50 worms and the maximum was 130.For each individual host the relative percentage parasite-weight to host-weight has been determined (parasitization index). In more than 50% of the fish the P.I. exceeded 25; the maximum value was 68·5. The relationship between P.I., numbers of worms and weight of worms is described.Some effects of parasitization on the host are described; they include gross distension of the body, reduction of liver weight, reduction of packed cell volume of erythrocytes and delay in oocyte maturation. In some heavily parasitized individuals spawning is apparently inhibited.Concurrent infections with the microsporidian Glugea anomala are described.Our thanks are due to Mr A. Rennie, B.Sc., of the Yorkshire Ouse and Hull River Authority for drawing our attention to the source of infected sticklebacks, to Mr A. O. Holliday for the preparation of photographs and to Mr G. R. Standley for assistance in the preparation of the slide shown in PI. 1, fig. 3. We also wish to thank Dr J. N. Ball, Department of Zoology, University of Sheffield, for his helpful comments on the gonads of infected fish, and Professor J. M. Dodd, Department of Zoology, University of Leeds, for providing facilities and much helpful discussion. One of us (C. A.) gratefully acknowledges the receipt of a Science Research Council Research Studentship and Fellowship.

The infectivity, growth, and virulence of the cestode Schistocephalus solidus in its first intermediate host, the copepod Macrocyclops albidus

Parasitology ◽  
1997 ◽  
Vol 115 (3) ◽  
pp. 317-324 ◽  
Author(s):  
C. WEDEKIND
Keyword(s):  
Intermediate Host ◽  
Adult Stage ◽  
Dilution Effect ◽  
Multiple Infections ◽  
Schistocephalus Solidus ◽  
Host Mortality ◽  
Copepodid Stage ◽  
First Intermediate Host ◽  
Observation Period ◽  
Growth And Reproduction

In an experiment to study the infectivity, growth and virulence of Schistocephalus solidus in their first intermediate host, copepods of the species Macrocyclops albidus were kept singly and exposed to up to 9 coracidia. Eleven or 14 days post-infection (p.i.) the presence and growth of the cestode larvae relative to survival, growth and reproduction of their host was determined. As expected, the probability of a copepod becoming infected increased with increasing numbers of parasites administered. However, the chances of a single coracidium establishing in a copepod also increased with increasing numbers of coracidia administered, which indicates that the parasites profit from a dilution effect of the host's defence. Copepod size or developmental stage had no significant effect on the infection, but 14 days p.i., constraining effects of copepod size on the growth of the parasites were apparent. Moreover, procercoids in multiple infections grew smaller and developed their cercomer at a smaller size than those in single infections. No significant effect of the parasite on host mortality was found within the observation period. However, growth between the 5th copepodid stage and adult stage was negatively affected by infection. An infection with S. solidus was also strongly linked with host reproduction: infected females were more likely to bear an egg sac at the end of the experiment than non-infected ones. These egg sacs, however, contained fewer eggs.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

Host mortality and variability in epizootics of Schistocephalus solidus infecting the threespine stickleback, Gasterosteus aculeatus

Parasitology ◽  
2010 ◽  
Vol 137 (11) ◽  
pp. 1681-1686 ◽  
Author(s):  
D. C. HEINS ◽  
E. L. BIRDEN ◽  
J. A. BAKER
Keyword(s):  
Gasterosteus Aculeatus ◽  
Infected Fish ◽  
Threespine Stickleback ◽  
Intensity Of Infection ◽  
Host Fish ◽  
Schistocephalus Solidus ◽  
Second Intermediate Host ◽  
Host Mortality ◽  
Abiotic And Biotic Factors ◽  
Host Behaviour

SUMMARYAn analysis of the metrics of Schistocephalus solidus infection of the threespine stickleback, Gasterosteus aculeatus, in Walby Lake, Alaska, showed that an epizootic ended between 1996 and 1998 and another occurred between 1998 and 2003. The end of the first epizootic was associated with a crash in population size of the stickleback, which serves as the second intermediate host. The likely cause of the end of that epizootic is mass mortality of host fish over winter in 1996–1997. The deleterious impact of the parasite on host reproduction and increased host predation associated with parasitic manipulation of host behaviour and morphology to facilitate transmission might also have played a role, along with unknown environmental factors acting on heavily infected fish or fish in poor condition. The second epizootic was linked to relatively high levels of prevalence and mean intensity of infection, but parasite:host mass ratios were quite low at the peak and there were no apparent mass deaths of the host. A number of abiotic and biotic factors are likely to interact to contribute to the occurrence of epizootics in S. solidus, which appear to be unstable and variable. Epizootics appear to depend on particular and, at times, rare sets of circumstances.

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