Parasites of the Brazilian flathead Percophis brasiliensis reflect West Atlantic biogeographic regions

Parasitology ◽  
2016 ◽  
Vol 144 (2) ◽  
pp. 169-178 ◽  
Author(s):  
PAOLA E. BRAICOVICH ◽  
CAMILA PANTOJA ◽  
ALDENICE N. PEREIRA ◽  
JOSE L. LUQUE ◽  
JUAN T. TIMI
Keyword(s):  
Distance Decay ◽  
Component Community ◽  
Significant Similarity ◽  
Marine Parasites ◽  
Latitudinal Patterns ◽  
Biogeographic Regions ◽  
Predicted Values ◽  
Fish Hosts ◽  
Parasite Assemblages ◽  
Percophis Brasiliensis

SUMMARYWith the aim of evaluating the utility of marine parasites as indicators of zoogeographical regions in the South West Atlantic, we analyzed data on assemblages of long-lived larval parasites of 488 specimens of Percophis brasiliensis distributed in 11 samples from nine localities covering the entire distribution of the species in the Argentine biogeographical Province. Near half a million long-lived parasite individuals belonging to 17 species present in the whole sample displayed clear latitudinal patterns. Data for parasite assemblages at infracommunity and component community levels were analysed in relation to the geographical distance. Significant similarity decay of parasite assemblages over distance was observed, with those based on abundances and mean abundances showing departures from predicted values of regressions. These departures were represented by higher dissimilarities between samples coming from different zoogeographical regions than between those caught within the same region, independently of the distance separating them. Consequently, zoogeographical regions were identified in a distance-decay context. Multivariate analyses corroborated a close fit of similarity between assemblages to existing zoogeographical classifications. Regressions representing distance decay of similarity, and the identification of their outliers, can therefore shed light on the existence of discontinuities or uniformities in the geographic distribution of parasite assemblages and, in turn, in the zoogeography of their fish hosts.

Patterns of variation in parasite component communities and infracommunities of a littoral fish species from the northern coast of Chile

2012 ◽  
Vol 88 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Vania Henríquez ◽  
M. Teresa González
Keyword(s):  
Fish Population ◽  
Host Population ◽  
Northern Coast ◽  
Component Community ◽  
Geographic Scale ◽  
Parasite Communities ◽  
Individual Host ◽  
Hierarchical Levels ◽  
Geographical Scale ◽  
Parasite Assemblages

AbstractThe structure and similarity of the parasite communities of fish can be evaluated at the component community (CC) and infracommunity (IC) levels. Both hierarchical levels have been used to assess parasite variations in fish at large (biogeographic) scales. However, studies evaluating the consistency between these two hierarchical levels at smaller geographical scales are scarce. In this study, the parasite assemblages of 124 Paralabrax humeralis collected by local fishermen by spear fishing at four sites (El Fierro, EF; P. Angamos, PA; Santa María, ISM; San Jorge, BSJ) in northern Chile were compared to assess the variability (or similarity) of their CCs and ICs at a limited geographical scale using multivariate analysis. At the IC level, discriminant analyses showed that P. humeralis parasite communities varied significantly among sites; 70% of ectoparasite ICs were correctly assigned to each site, but only 55% of helminth parasite ICs were correctly classified. At the CC level, the composition of parasite communities as assessed by correspondence analyses varied significantly between sites. Tagia sp., Neobenedenia sp. and Philometra sp. were associated with BSJ, ISM and PA, respectively; Corynosoma sp. and most digeneans were associated with both ISM and EF. Analysis of similarities (ANOSIM) showed significant variations in the degree of similarity between P. humeralis CCs from different sites, but not between ICs. Variations between CCs from different sites reflect fish population processes (e.g., population age, reproductive segregation) and the particular conditions of their respective habitats, whereas ICs reflect individual host movements. This study demonstrated that, when examined at a limited geographical scale, IC is better than CC at capturing the local pool of parasite assemblages when host populations are spatially segregated. Therefore, in this study, it is demonstrated that at a small geographic scale, CC variations are not reflected by IC, when host population is spatially segregated.

Eels at the Edge: Science, Status, and Conservation Concerns

2009 ◽  
Keyword(s):  
Environmental Changes ◽  
Ecological Integrity ◽  
Anguilla Anguilla ◽  
Current Status ◽  
Economic Damage ◽  
Intermediate Hosts ◽  
Fish Introductions ◽  
Individual Host ◽  
Fish Hosts ◽  
Parasite Assemblages

<em>Abstract.</em>—A new checklist of 36 metazoan parasites recorded in European eels <em>Anguilla anguilla </em>in Ireland is presented and reviewed. Some of these parasite taxa are eel specialists but most utilize a range of fish hosts. Many were accidentally brought to Ireland during fish introductions. Changing distributions of preferred intermediate hosts have affected some parasite species. Commercial transport of eels has been implicated in the introduction and spread of several potentially pathogenic parasites, including the Asian nematode <em>Anguillicola crassus</em>. The current status of this and two <em>Pseudodactylogyrus </em>species, similarly introduced to Ireland, is discussed. Analysis of parasite assemblages of Irish eel populations indicates that individual host characteristics, such as size and diet, are important at the infra-community level. Likewise, variation in biotic and abiotic features of ecosystems is reflected in composition and structure of eel parasite component communities. Environmental changes, such as eutrophication and species introductions, were found to affect eel parasite assemblages. Better regulation of fish introductions and translocations is needed to protect the ecological integrity of Ireland’s freshwater systems and to avoid economic damage by nonindigenous parasites. Restrictions on live eel transport and on eel stocking programs may be necessary to protect recreational fisheries and the Irish aquaculture industry.

Parasite Assemblages Infecting Native Versus An Introduced Population of Yellow Bass

2016 ◽  
Vol 123 (1-4) ◽  
pp. 1-2
Author(s):  
Rick Klann
Keyword(s):  
Mississippi River ◽  
Alimentary Canal ◽  
The Other ◽  
Fish Parasites ◽  
Native Range ◽  
Native Population ◽  
Metazoan Parasites ◽  
Fish Hosts ◽  
Parasite Assemblages ◽  
Introduced Population

The parasite assemblage infecting yellow bass (Morone mississippiensis) inhabiting their native range was compared to the assemblage infecting an introduced population. The gills and alimentary canal of 47 yellow bass collected from the Mississippi River (native) and 41 yellow bass collected from Otter Creek Lake in Tama County, Iowa, (introduced) were examined for metazoan parasites. Species richness was higher in the sample from the native population compared to the introduced sample (8 versus 3, respectively). Yellow bass from the introduced sample hosted species that were generalist fish parasites, and these infections were at low intensities. On the other hand, yellow bass from the native sample were infected with high numbers of Allacanthochasmus varius and Neochasmus umbellus, which have been reported from a smaller number of fish hosts, and in the case of A. varius, primarily in genus Morone.

Parasite assemblages in fish hosts

Bio-Research ◽  
2010 ◽  
Vol 7 (2) ◽  
Author(s):  
F Iyaji ◽  
L Etim ◽  
J Eyo
Keyword(s):  
Fish Hosts ◽  
Parasite Assemblages

Influence of stable iodine on the uptake of the thyroid – model vs. experiment

2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber
Keyword(s):  
Time Course ◽  
Compartment Model ◽  
The Body ◽  
Iodine Uptake ◽  
Model Calculations ◽  
Physiological Conditions ◽  
Iodine Supply ◽  
Predicted Values ◽  
The Individual ◽  
Stable Iodine

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.

Status of same-sex partnerships in Ukraine

2020 ◽  
pp. 143-166
Author(s):  
MAKSYM KASIANZUK ◽  
SVIATOSLAV SHEREMET ◽  
OLESIA TROFYMENKO
Keyword(s):  
National Level ◽  
Quantitative Information ◽  
Academic Community ◽  
Small Sample ◽  
Bisexual Men ◽  
Same Sex ◽  
Significant Similarity ◽  
Male Couples ◽  
Same Sex Couples ◽  
And Bisexual

The proposed article aims to summarize available quantitative and qualitative data on same-sex partnerships in Ukraine, including data on the presence of children in such partnerships, over the last twenty years (1999–2018). The increasing number of publications on various aspects of the existence of same-sex couples in English demonstrates the relevance of the topic. The information available in Ukraine is the richest in comparison with other post-Soviet countries of the Central and Eastern Europe and Central Asia region. At the same time, LGBT families remain out of the academic community in Ukraine, and the data collected are mostly contained in the so-called "gray literature" (mainly research reports by public organizations), and are not introduced into scientific circulation. It is shown that, depending on the composition of the sample and the definition of same-sex partnership used by the researchers, this percentage most often falls within the range of 16–28% of surveyed homosexual and bisexual men residing in the capital and regional centers of Ukraine. Quantitative information on women partnerships is extremely limited (one survey of a small sample), and there is no quantitative data for the couples, where one or both partners are transgenders. Quantitative information on children in same-sex partnerships is also very limited, and the data in the literature (with all the methodological disadvantages indicated) ranges from 14% to 29% of LGB, which have children, but it is unknown whether these children were raised in same-sex couples. With regard to quality information, the situation is different — a little bit more is known about the status of women and partly transgender partnerships (including the issue of children in such families) than about male couples. Separate data demonstrates a significant similarity in the same-sex partnership structure to the typical heterosexual egalitarian family model (two partners and their children), taking into account more egalitarian marriage roles, lack of formal status, and associated socio-economic risks. Further research (including national level) should be based on a common understanding of what constitutes “same-sex partnership”, what are the characteristics of same-sex partnership (civil, family), what characteristics of civil partnership turn it into a“family”, etc.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

Metazoan Parasites and Health State of European Eel, Anguilla Anguilla (Anguilliformes, Anguillidae), From Tonga Lake and El Mellah Lagoon in the Northeast of Algeria

2018 ◽  
Vol 52 (4) ◽  
pp. 279-288 ◽  
Author(s):  
F. Bakaria ◽  
S. Belhaoues ◽  
N. Djebbari ◽  
M. Tahri ◽  
I. Ladjama ◽  
...  
Keyword(s):  
Brackish Water ◽  
Parasite Species ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Health State ◽  
Component Community ◽  
Metazoan Parasites ◽  
Parasite Communities ◽  
High Dominance ◽  
Argulus Foliaceus

Abstract The aim of the study was to examine metazoans parasite communities of European eels (Anguilla anguilla) in freshwater (Tonga Lake) and brackish water (El Mellah lagoon) in the northeast of Algeria. Six parasite taxa were collected: one monogenean, Pseudodactylogyrus sp.; two crustaceans, Ergasilus sp. and Argulus foliaceus; two nematodes, Cucullanus sp. and Anguillicola crassus; one cestode, Bothriocephalus claviceps. Th e most prevalent parasite taxa in freshwater were Pseudodactylogyrus sp., A. crassus and Bothriocephalus claviceps; whereas in the brackish water, eels were infected mainly with A. crassus. Th e characteristics of the parasite component community structure revealed low parasite species diversity and high dominance values in eels from the two localities. Both communities were dominated by a single parasite species: Tonga eels by the monogenean Pseudodactylogyrus sp. and El Mellah lagoon eels by the nematode A. crassus, verified by high Berger-Parker dominance values of 0.76 and 0.87 respectively.

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