How have fisheries affected parasite communities?

Parasitology ◽  
2014 ◽  
Vol 142 (1) ◽  
pp. 134-144 ◽  
Author(s):  
CHELSEA L. WOOD ◽  
KEVIN D. LAFFERTY
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Parasite Species ◽  
Meta Analysis ◽  
Complex Life Cycle ◽  
Parasite Diversity ◽  
Parasite Abundance ◽  
Parasite Communities ◽  
Or Groups ◽  
Parasite Assemblages

SUMMARYTo understand how fisheries affect parasites, we conducted a meta-analysis of studies that contrasted parasite assemblages in fished and unfished areas. Parasite diversity was lower in hosts from fished areas. Larger hosts had a greater abundance of parasites, suggesting that fishing might reduce the abundance of parasites by selectively removing the largest, most heavily parasitized individuals. After controlling for size, the effect of fishing on parasite abundance varied according to whether the host was fished and the parasite's life cycle. Parasites of unfished hosts were more likely to increase in abundance in response to fishing than were parasites of fished hosts, possibly due to compensatory increases in the abundance of unfished hosts. While complex life cycle parasites tended to decline in abundance in response to fishing, directly transmitted parasites tended to increase. Among complex life cycle parasites, those with fished hosts tended to decline in abundance in response to fishing, while those with unfished hosts tended to increase. However, among directly transmitted parasites, responses did not differ between parasites with and without fished hosts. This work suggests that parasite assemblages are likely to change substantially in composition in increasingly fished ecosystems, and that parasite life history and fishing status of the host are important in predicting the response of individual parasite species or groups to fishing.

scholarly journals Malaria Parasite Stress Tolerance Is Regulated by DNMT2-Mediated tRNA Cytosine Methylation

mBio ◽  
2021 ◽  
Author(s):  
Elie Hammam ◽  
Ameya Sinha ◽  
Sebastian Baumgarten ◽  
Flore Nardella ◽  
Jiaqi Liang ◽  
...  
Keyword(s):  
Life Cycle ◽  
Malaria Parasite ◽  
Cytosine Methylation ◽  
Parasite Species ◽  
Environmental Stressors ◽  
Complex Life Cycle ◽  
Content Type ◽  
Mortality And Morbidity ◽  
Disease Mortality ◽  
New Strategies

P. falciparum is the most virulent malaria parasite species, accounting for the majority of the disease mortality and morbidity. Understanding how this pathogen is able to adapt to different cellular and environmental stressors during its complex life cycle is crucial in order to develop new strategies to tackle the disease.

scholarly journals Diversification dynamics of hypermetamorphic blister beetles (Meloidae): Are homoplastic host shifts and phoresy key factors of a rushing forward strategy to escape extinction?

2021 ◽  
Author(s):  
E.K. López-Estrada ◽  
I. Sanmartín ◽  
J.E. Uribe ◽  
S. Abalde ◽  
M. García-París
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Life History Traits ◽  
Complex Life Cycle ◽  
Life Strategies ◽  
Diversification Rates ◽  
Host Shifts ◽  
Extinction Rates ◽  
State Dependent ◽  
History Of

ABSTRACTChanges in life history traits, including reproductive strategies or host shifts, are often considered triggers of speciation, affecting diversification rates. Subsequently, these shifts can have dramatic effects on the evolutionary history of a lineage. In this study, we examine the consequences of changes in life history traits, in particular host-type and phoresy, within the hypermetamorphic clade of blister beetles (Meloidae). This clade exhibits a complex life cycle involving multiple metamorphoses and parasitoidism. Most tribes within the clade are bee-parasitoids, phoretic or non-phoretic, while two tribes feed on grasshopper eggs. Species richness differs greatly between bee and grasshopper specialist clades, and between phoretic and non-phoretic genera. We generated a mitogenomic phylogeny of the hypermetamorphic clade of Meloidae, including 21 newly generated complete mitogenomes. The phylogeny and estimated lineage divergence times were used to explore the association between diversification rates and changes in host specificity and phoresy, using State-Dependent Speciation and Extinction (SSE) models, while accounting for hidden factors and phylogenetic uncertainty within a Bayesian framework. The ancestor of the hypermetamorphic Meloidae was a non-phoretic bee-parasitoid, and independent transitions towards phoretic bee-parasitoidism or grasshopper specialization occurred multiple times. Bee-parasitoid lineages that are non-phoretic have significantly higher relative extinction rates and lower diversification rates than grasshopper specialists or phoretic bee-parasitoids, while no significant differences were found between the latter two strategies. This suggests that these two life strategies contributed independently to the evolutionary success of Nemognathinae and Meloinae, allowing them to escape from the evolutionary constraints imposed by their hypermetamorphic life-cycle, and that the “bee-by-crawling” strategy may be an evolutionary “dead end”. We show how SSE models can be used not only for testing diversification dependence in relation to the focal character but to identify hidden traits contributing to the diversification dynamics. The ability of blister beetles to explore new evolutionary scenarios including the development of homoplastic life strategies, are extraordinary outcomes along the evolution of a single lineage: the hypermetamorphic Meloidae.

scholarly journals Latitudinal gradient in the taxonomic composition of parasite communities

2010 ◽  
Vol 85 (3) ◽  
pp. 228-233 ◽  
Author(s):  
R. Poulin ◽  
T.L.F Leung
Keyword(s):  
Species Richness ◽  
Parasite Species ◽  
Parasite Community ◽  
Taxonomic Composition ◽  
Latitudinal Gradients ◽  
Latitudinal Variation ◽  
Parasite Communities ◽  
Helminth Communities ◽  
Vertebrate Hosts ◽  
Parasite Assemblages

AbstractAlthough latitudinal gradients in diversity have been well studied, latitudinal variation in the taxonomic composition of communities has received less attention. Here, we use a large dataset including 950 surveys of helminth endoparasite communities in 650 species of vertebrate hosts to test for latitudinal changes in the relative contributions of trematodes, cestodes, nematodes and acanthocephalans to parasite assemblages. Although the species richness of helminth communities showed no consistent latitudinal variation, their taxonomic composition varied as a function of both host type and latitude. First, trematodes and acanthocephalans accounted for a higher proportion of species in helminth communities of fish, whereas nematodes achieved a higher proportion of the species in communities of bird and especially mammal hosts. Second, the proportion of trematodes in helminth communities of birds and mammals increased toward higher latitudes. Finally, the proportion of nematodes per community increased toward lower latitudes regardless of the type of host. We present tentative explanations for these patterns, and argue that new insights in parasite community ecology can be gained by searching for latitudinal gradients not only in parasite species richness, but also in the taxonomic composition of parasite assemblages.

Similarity and structure of the ectoparasite communities of rockfish species from the southern Chilean coast in a temporal scale

Parasitology ◽  
2006 ◽  
Vol 133 (3) ◽  
pp. 335-343 ◽  
Author(s):  
M. T. GONZÁLEZ ◽  
M. E. OLIVA
Keyword(s):  
Species Richness ◽  
Parasite Species ◽  
Parasite Community ◽  
Temporal Scale ◽  
Parasite Abundance ◽  
Parasite Communities ◽  
Chilean Coast ◽  
Patterns And Processes ◽  
Prevalent Species

The understanding of the patterns and processes underlying the structure of parasite communities has progressed significantly in the last years; however, much of the evidence available to date on parasite community comes from unconfirmed studies. In this study the ectoparasite communities of 2 related rockfishes, Sebastes capensis and Helicolenus lengerichi, from the southern Chilean coast (ca. 40 °S) were examined to determine whether their specific compositions are similar, structured in non-random ways, and repeatable among years. From 2001 to 2004, 189 specimens of S. capensis and 101 of H. lengerichi were examined, 10 and 9 parasite species were recorded in S. capensis and H. lengerichi, respectively. Component ectoparasite communities of these hosts were taxonomically similar (60%), but the abundances and prevalences of their parasites differed significantly among years and between hosts. The most prevalent species were Lepeophtheirus chilensis, and Microcotyle sp. for S. capensis, and Microcotyle sp., Juanetia continentalis, and Interniloculus chilensis for H. lengerichi. Infracommunities of S. capensis showed higher species richness and parasite numbers than those of H. lengerichi. The similarity among infracommunities (measured as parasite abundance) varied significantly among years both within and between hosts. Despite this, temporal nestedness patterns were observed in infracommunities of these hosts, suggesting that their ectoparasite communities are structured and might be predictable in time, at least in the southern Chilean coast where they share the same habitat.

Order in ectoparasite communities of marine fish is explained by epidemiological processes

Parasitology ◽  
2002 ◽  
Vol 124 (7) ◽  
pp. 57-63 ◽  
Author(s):  
S. MORAND ◽  
K. ROHDE ◽  
C. HAYWARD
Keyword(s):  
Community Structure ◽  
Interspecific Competition ◽  
Marine Fish ◽  
Positive Relationship ◽  
Parasite Species ◽  
Holistic Approach ◽  
Bimodal Distribution ◽  
Parasite Communities ◽  
The Mean ◽  
Parasite Assemblages

Two kinds of community structure referred to, nestedness and bimodal distribution, have been observed or were searched for in parasite communities. We investigate here the relation between these two kinds of organisation, using marine fishes as a model, in order to show that parasite population dynamics may parsimoniously explain the patterns of ectoparasite species distribution and abundance. Thirty six assemblages of metazoan ectoparasites on the gills and heads of marine fish showed the following patterns: a positive relationship between abundance and the variance of abundance; a positive relationship between abundance and prevalence of infection; a bimodal pattern of the frequency distribution of prevalence of infection; nestedness as indicated by Atmar and Patterson's thermodynamic measure (a mean of 7.9°C); a unimodal distribution of prevalence in parasite assemblages with a temperature lower than the mean, and a bimodal distribution in assemblages with a temperature higher than the mean. We conclude that patterns are the result of characteristics of the parasite species themselves and that interspecific competition is not necessary to explain them. We emphasize that a holistic approach, taking all evidence jointly into account, is necessary to explain patterns of community structure. Ectoparasite assemblages of marine fish are among the animal groups that have been most thoroughly examined using many different methods, and all evidence supports the view that these animals live under non-equilibrium conditions, in largely non-saturated niche space in which interspecific competition occurs but is of little evolutionary importance.

scholarly journals Compilation of 29-year postmortem examinations identifies major shifts in equine parasite prevalence from 2000 onwards

2019 ◽  
Author(s):  
G. Sallé ◽  
J. Guillot ◽  
J. Tapprest ◽  
N. Foucher ◽  
C. Sevin ◽  
...  
Keyword(s):  
Parasite Species ◽  
Temporal Trend ◽  
Parasitic Infection ◽  
Parasite Prevalence ◽  
Form Complex ◽  
Parasite Abundance ◽  
Parasite Communities ◽  
Wide Range ◽  
Year 2000 ◽  
Death Cases

AbstractHorses are infected by a wide range of parasite species that form complex communities. Parasite control imposes significant constraints on parasite communities whose monitoring remains however difficult to track through time. Postmortem examination is a reliable method to quantify parasite communities. Here, we compiled 1,673 necropsy reports accumulated over 29 years, in the reference necropsy centre from Normandy (France). The burden of non-strongylid species was quantified and the presence of strongylid species was noted. Details of horse deworming history and the cause of death were registered. Building on these data, we investigated the temporal trend in non-strongylids epidemiology and we determined the contribution of parasites to the death of horses throughout the study period. Data analyses revealed the seasonal variations of non-strongylid parasite abundance and reduced worm burden in race horses. Beyond these observations, we found a shift in the species responsible for fatal parasitic infection from the year 2000 onward, whereby fatal cyathostominosis and Parascaris spp. infection have replaced death cases caused by S. vulgaris and tapeworms. Concomitant break in the temporal trend of parasite species prevalence was also found within a 10-year window (1998-2007) that has seen the rise of Parascaris spp. and the decline of both Gasterophilus spp. and tapeworms. A few cases of parasite persistence following deworming were identified that all occurred after 2000. Altogether, these findings provide insights into major shifts in non-strongylid parasite prevalence and abundance over the last 29 years. They also underscore the critical importance of Parascaris spp. in young equids.

scholarly journals Compensating for a bad start: compensatory growth across life stages in an organism with a complex life cycle

2016 ◽  
Vol 94 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Lee Hyeun-Ji ◽  
Frank Johansson
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Adult Stage ◽  
Mass Gain ◽  
High Mass ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Use Of Resources ◽  
Low Mass ◽  
Lestes Sponsa

Organisms with a complex life cycle are characterized by a life-history shift through metamorphosis and include organisms such as insects and amphibians. They must optimize their use of resources and behaviour across different life stages to maximize their fitness. An interesting question with regard to such life-history shifts is whether growth in the juvenile stage can be compensated for in the adult stage. Here we ask whether emerald damselflies (Lestes sponsa (Hansemann, 1823)) are able to compensate for depressed growth during the juvenile aquatic stage in their terrestrial adult stage. Lestes sponsa emerge at a fixed adult body size, but feed during the adult stage and are thus able to gain mass as adults. We performed a mark–recapture study to answer whether individuals that emerge from metamorphosis with a low mass are able to compensate by subsequent mass gain during the adult stage. Results showed that compensatory mass gain occurred in the adult stage such that small individuals gained more mass than large individuals. We also found that females gained more mass than males. However, individuals that emerged at a low mass still had lower mass as mature adults than individuals that emerged at a high mass, suggesting that compensation was not complete. This suggests that larval ecology and adult fitness are tightly linked and future research should focus more on elucidating the nature of this relationship.

Disentangling the beta-diversity in anuran parasite communities

Parasitology ◽  
2020 ◽  
pp. 1-6
Author(s):  
Elvira D'Bastiani ◽  
Karla M. Campião
Keyword(s):  
Beta Diversity ◽  
Parasite Species ◽  
Random Pattern ◽  
Phylogenetic Species ◽  
Parasite Communities ◽  
Anuran Species ◽  
Great Heterogeneity ◽  
Main Component ◽  
Scientific Quest ◽  
Parasite Assemblages

Abstract There is great heterogeneity in parasite communities among hosts, understanding the nature and drivers of such variations is still a great scientific quest. Here, we analyse the variation in parasite communities by addressing the following questions: (i) What is the beta-diversity component (nestedness or turnover) that most contributes to beta diversity in parasite communities among anuran species? (ii) Does the beta diversity of parasite communities follow a non-random pattern? (iii) Is the dissimilarity in composition of parasite communities related to the phylogenetic or functional dissimilarity among hosts? We found that turnover in parasite assemblages was the main component of beta diversity, but the variation observed both in the total beta diversity and in its components did not differ from the respective null models. The dissimilarity among parasite communities was not related to the phylogenetic species variability or functional dissimilarity among anuran species for most localities. In short, our findings may indicate a process of resource tracking by the parasite species, in which the resource may not necessarily be conserved phylogenetically in their hosts.

Alternative life-history and transmission strategies in a parasite: first come, first served?

Parasitology ◽  
2005 ◽  
Vol 132 (1) ◽  
pp. 135-141 ◽  
Author(s):  
R. POULIN ◽  
F. LEFEBVRE
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Intermediate Host ◽  
Host Location ◽  
Parasite Species ◽  
Fish Host ◽  
Transmission Strategy ◽  
External Cues ◽  
Host Life ◽  
Host Tissues

Alternative transmission strategies are common in many parasitic organisms, often representing discrete phenotypes adopted in response to external cues. The facultative truncation of the normal 3-host life-cycle to a 2-host cycle in many trematodes provides an example: some individuals mature precociously, via progenesis, in their intermediate host and produce eggs without the need to reach a definitive host. The factors that determine how many and which individuals adopt the truncated life-cycle within a parasite population remain unknown. We investigated the occurrence of progenesis in the trematode Stegodexamene anguillae within its fish intermediate host. Location within the host was a key determinant of progenesis. Although the size and egg output of progenetic metacercariae encysted in host gonads did not differ from those of the few progenetic metacercariae in other host tissues, the likelihood of metacercariae becoming progenetic was much higher for those in the gonads than those elsewhere in the host. Progenetic parasites can only evacuate their eggs along with host eggs or sperm, providing a link between the parasite's transmission strategy and its location in the host. Host size and sex, and the presence of other parasite species in the host, did not affect the occurrence of progenesis in S. anguillae. However, the proportion of metacercariae in host gonads and the proportion of progenetic metacercariae both decreased with increasing numbers of S. anguillae per host. These results suggest that progenesis is adopted mostly by the parasites that successfully establish in host gonads. These are generally the first to infect a fish; subsequent arrivals settle in other tissues as the gonads quickly become saturated with parasites. In this system, the site of encystment within the fish host both promotes and constrains the adoption of a facultative, truncated life-cycle by the parasite.

Sign in / Sign up

Export Citation Format

Share Document