scholarly journals Helminth parasites in two populations of Astronotus ocellatus (Cichliformes: Cichlidae) from the eastern Amazon, Northern Brazil

2019 ◽  
Vol 28 (3) ◽  
pp. 425-431
Author(s):  
Raul Henrique da Silva Pinheiro ◽  
Marcos Tavares-Dias ◽  
Elane Guerreiro Giese
Keyword(s):  
Diversity Index ◽  
Helminth Parasite ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Component Community ◽  
Parasite Communities ◽  
Shannon Diversity ◽  
Astronotus Ocellatus ◽  
Northern Brazil ◽  
Two Populations

Abstract This study compared the structure of helminth parasite communities in two populations of Astronotus ocellatus from two localities in Pará State, eastern Amazon (Brazil). Hosts from the Tapajós River were infected by Posthodiplostomum sp. metacercarie, larvae of Contracaecum sp. and Pseudoproleptus sp., with predominance of Contracaecum sp. Hosts from Iara Lake were infected by Procamallanus spiculastriatus, Proteocephalus sp. and Acanthocephala gen. sp., with predominance of P. spiculastriatus. Parasites had an aggregated dispersion and there were differences in Shannon diversity index and the evenness between both host populations, because the parasite component community showed no similarity. The existence of variation in infracommunity and community of parasites for A. ocellatus from different localities indicates the presence of an uneven distribution in terms of species and density of parasites, as well as of intermediate hosts in the localities surveyed.

Intestinal helminth parasites in flounderPlatichthys flesusfrom the River Thames: an infracommunity analysis

2004 ◽  
Vol 78 (4) ◽  
pp. 297-303 ◽  
Author(s):  
S. Guillen-Hernandez ◽  
P.J. Whitfield
Keyword(s):  
Parasite Species ◽  
Parasite Community ◽  
Intestinal Helminth ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Component Community ◽  
Parasite Communities ◽  
High Prevalence ◽  
Marine Influence ◽  
River Thames

AbstractAn analysis was undertaken of intestinal helminth communities in flounderPlatichthys flesusfrom two sites on the River Thames. A comparison was made between helminth community richness and diversity from these sites at the component and infracommunity levels. At the component community level, a richer and more diverse parasite community was found in flounder from the Tilbury location (marine influence) than that from the Lots Road location (freshwater influence). At the infracommunity level, more parasite species and parasite individuals per host were found at Lots Road and the percentage of similarity values were low at both locations. Helminth species with high prevalence values in the parasite communities of the flounder are the dominant species in any individual fish, harbouring multi-specific infections. The presence of more invertebrate species, which are intermediate hosts in the helminth life cycle in the Thames, fish vagility and the high prevalence and abundance values ofPomphorhynchus laevisin the flounder, may explain the differences between the two locations.

Helminth parasite communities in four species of sympatric macropodids in western Victoria

2011 ◽  
Vol 33 (1) ◽  
pp. 13 ◽  
Author(s):  
M. Aussavy ◽  
E. Bernardin ◽  
A. Corrigan ◽  
J. Hufschmid ◽  
I. Beveridge
Keyword(s):  
Host Species ◽  
Helminth Parasite ◽  
Helminth Parasites ◽  
Detailed Data ◽  
Sympatric Distribution ◽  
Parasite Communities ◽  
Parasite Specificity ◽  
Wallabia Bicolor ◽  
Western Victoria ◽  
Ecological Differences

Helminth parasites of Macropus fuliginosus, M. giganteus, M. rufogriseus and Wallabia bicolor were examined in a region of western Victoria, Australia, where all four species of hosts are sympatric. M. fuliginosus and M. giganteus shared most of their parasites while the helminth communities of M. rufogriseus and W. bicolor were distinctive. The sympatric distribution of the host species studied provides evidence in support of the hypothesis that the differences between the parasite communities of M. fuliginosus–M. giganteus compared with those of M. rufogriseus and W. bicolor are due to parasite specificity rather than to host ecological differences. However, lack of detailed data on the ecological differences of these hosts in areas of sympatry prevents more precise conclusions being drawn on the reasons for the distinctiveness of the parasite communities.

scholarly journals Communities of metazoan parasites of two fishes of the Proterorhinus genus (Actinopterygii: Gobiidae)

2009 ◽  
Vol 46 (3) ◽  
pp. 168-176 ◽  
Author(s):  
Yuriy Kvach ◽  
Mehmet Oğuz
Keyword(s):  
Parasite Species ◽  
The Black Sea ◽  
Intermediate Hosts ◽  
Great Tendency ◽  
Component Community ◽  
Metazoan Parasites ◽  
Parasite Communities ◽  
Marine Parasite ◽  
Nicolla Skrjabini

AbstractMetazoan parasite communities of two gobiids, Proterorhinus marmoratus and P. semilunaris, which are common small-sized fishes native for the Black Sea basin, were studied. The parasite component community of P. marmoratus is represented by 11 species (one monogenean, one cestode, five digeneans, two nematodes, and two acanthocephalans). P. semilunaris had 5 species (one monogenean, one cestode, one digenean, one nematode, and one acanthocephalan). Acanthocephaloides propinquus has a great tendency to join the infracommunity. The differences between the parasite component communities of two Proterorhinus gobies are explained by different quality of habitats and available intermediate hosts. The component community of parasites of P. marmoratus is formed by brackish-water and marine parasite species, and that of P. semilunaris consists of limnetic parasite species. The euryhaline G. proterorhini is the only parasite species found in both P. marmoratus and P. semilunaris. In both species of gobiids, the main abundant parasite species (A. propinquus in P. marmoratus and Nicolla skrjabini in P. semilunaris) infest the host by feeding on crustaceans.

Occurrence of intermediate hosts and structure of digenean communities of the black-headed gull, Larus ridibundus (L.)

Parasitology ◽  
2003 ◽  
Vol 126 (1) ◽  
pp. 69-78 ◽  
Author(s):  
A. šIMKOVÁ ◽  
J. SITKO ◽  
J. OKULEWICZ ◽  
S. MORAND
Keyword(s):  
Species Diversity ◽  
Water Reservoir ◽  
Life Cycles ◽  
Intermediate Hosts ◽  
Component Community ◽  
Parasite Communities ◽  
Digenean Species ◽  
As Species ◽  
Geographical Distances ◽  
Drying Up

The factors contributing to the similarity between digenean parasite assemblages parasitizing the black-headed gull were investigated. Thirteen different digenean species from the digestive tract and the bursa of Fabricus were found. We predicted that the structure of parasite communities is not random at either component community or infracommunity levels. We searched for nested patterns in the digenean community, and explored the possible factors contributing to nestedness. We found that digenean species which occupy a narrow range of intermediate hosts are placed out of order in the nested matrix. The influence of several variables related to the water reservoir, geographical distances, and the abundance of intermediate hosts on the species diversity and similarity of parasite communities were tested as well. Because of the complexity in bird digenean life-cycles we supposed that intermediate hosts and ecological characters of their environment could play a major role. We showed that the presence of intermediate hosts is the factor limiting the qualitative and quantitative similarity of parasite communities among different host populations as well as influencing the digenean species diversity in the definitive host. The similarity in abundance of intermediate hosts between different localities was facilitated by the presence of vegetation in water reservoir and more diversified type of water bottom. Digenean species diversity was higher when the water reservoir was exposed to temporal drying. We hypothesized that this factor could facilitate the inclusion of molluscs infected by digeneans in the diet of birds. Both species diversity and dominance were influenced by the bottom type of water reservoir and temporal drying up. Geographical distances between localities influenced the quantitative similarity of digenean communities as well as species richness.

scholarly journals Variation in the helminth community structure in bank voles (Clethrionomys glareolus) from three comparable localities in the Mazury Lake District region of Poland

Parasitology ◽  
2001 ◽  
Vol 123 (4) ◽  
pp. 401-414 ◽  
Author(s):  
J. M. BEHNKE ◽  
C. J. BARNARD ◽  
A. BAJER ◽  
D. BRAY ◽  
J. DINMORE ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Habitat Quality ◽  
The Other ◽  
Clethrionomys Glareolus ◽  
Helminth Parasite ◽  
Component Community ◽  
Parasite Communities ◽  
Host Sex ◽  
Index Of Diversity

We tested the null hypothesis that populations of hosts trapped in isolated neighbouring locations showing comparable habitat quality, should support similar helminth parasite communities. The study was undertaken in a 2-week period in late summer in NE Poland in a single year, thereby eliminating seasonal and between-year variation in parasite burdens. A total of 139 Clethrionomys glareolus (bank vole) were sampled from 3 forest sites of similar habitat quality. Total species richness was 11 (6 nematodes and 5 cestodes) with 85·6% of the voles carrying at least 1 species and an overall mean species richness of 1·4. At the component community level, the fewest species of helminths were recorded from site 2 (n = 6, compared with 9 at each of the other sites), but site 3 had the lowest Berger-Parker Dominance Index and the highest Simpson's Index of Diversity. At the infracommunity level, site 3 had the highest mean no. of helminth species/vole, the highest mean Brillouin's Index of Diversity but the lowest mean no. of helminths/vole. Voles from sites 1 and 3 differed in the nematodes that were most common (site 1, Heligmosomum mixtum – 95%; site 3, Heligmosomoides glareoli – 79·3%). At site 2 no species exceeded 50% but prevalence of Syphacia petrusewiczi was higher than at the other sites. The prevalence of cestodes was too low to test reliably (12·9%), but the highest prevalence of adult cestodes was recorded at site 1 (22·5% compared with 4·9 and 1·7% for sites 2 and 3 respectively). Host sex did not influence infection, but mean species richness increased with age. The different sites were responsible for most of the variation in our data, and the intrinsic factors (sex and age) were less important in shaping the component community structure of helminths. We conclude that even locations in relative close proximity to one another (13–25 km), selected on the basis of similar habitat quality, have rodent populations that differ in their helminth parasite communities, although for reasons other than the factors quantified in the present study.

New records of helminth parasites of nine species of waterfowl in Mexico, and a checklist of the helminth fauna of Anatidae occurring in Mexican wetlands

2020 ◽  
Vol 94 ◽  
Author(s):  
P. Padilla-Aguilar ◽  
E. Romero-Callejas ◽  
D. Osorio-Sarabia ◽  
G. Pérez–Ponce de León ◽  
Y. Alcalá-Canto
Keyword(s):  
Migratory Birds ◽  
Economic Benefits ◽  
Parasite Fauna ◽  
Helminth Parasite ◽  
Human Consumption ◽  
Freshwater Ecosystem ◽  
Helminth Parasites ◽  
Habitat Conditions ◽  
Parasite Communities ◽  
The Family

Abstract Wild and domestic populations of waterfowl garner economic benefits, as they are hunted for human consumption or as a recreational activity. Waterfowl migrate to their wintering grounds in Mexican wetlands where habitat conditions are more favourable. In this study, we present a list of helminth species sampled from the gastrointestinal tract of 59 wild birds belonging to the family Anatidae in three localities of Mexico, and a checklist of the helminth parasite fauna of the members of the family in the whole country, built from literature records. After helminthological examination, 25 taxa were identified: eight trematodes; four cestodes; 12 nematodes; and one acanthocephalan. Obtained records dated from 1943 to 2019. Our literature search yielded 563 records corresponding to 95 parasite taxa: 38 trematodes, 24 cestodes, 23 nematodes and ten acanthocephalans. In Mexico, 17 anatid species have been studied for helminths. Records correspond to 55 locations from 20 Mexican states. An insight gained from the collated literature and recent records was that trematodes represent the most diverse parasite group in anatids in Mexico. We briefly discuss that the information about helminths parasitizing waterfowl will be useful for understanding the effect of habitat loss and pollution of wetlands where migratory birds spend the breeding season, for addressing ecological programs aimed to guarantee the health and conservation of North American migratory birds or the effect of bird migration in the composition of the helminth parasite communities, and for freshwater biologists interested in the understanding of freshwater ecosystem health.

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.

scholarly journals On a Variational Definition for the Jensen-Shannon Symmetrization of Distances Based on the Information Radius

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 464
Author(s):  
Frank Nielsen
Keyword(s):  
Diversity Index ◽  
Diversity Indices ◽  
Shannon Diversity Index ◽  
Probability Measures ◽  
Variational Optimization ◽  
Shannon Diversity ◽  
Concept Of Information ◽  
Jensen Shannon Divergence

We generalize the Jensen-Shannon divergence and the Jensen-Shannon diversity index by considering a variational definition with respect to a generic mean, thereby extending the notion of Sibson’s information radius. The variational definition applies to any arbitrary distance and yields a new way to define a Jensen-Shannon symmetrization of distances. When the variational optimization is further constrained to belong to prescribed families of probability measures, we get relative Jensen-Shannon divergences and their equivalent Jensen-Shannon symmetrizations of distances that generalize the concept of information projections. Finally, we touch upon applications of these variational Jensen-Shannon divergences and diversity indices to clustering and quantization tasks of probability measures, including statistical mixtures.

The ecology of parasites of freshwater fishes: the search for patterns

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1653-1662 ◽  
Author(s):  
C. R. KENNEDY
Keyword(s):  
Community Dynamics ◽  
Parasite Community ◽  
Freshwater Fishes ◽  
Convincing Evidence ◽  
Helminth Parasites ◽  
Parasite Communities ◽  
Space And Time ◽  
Long Time ◽  
Population And Community Dynamics ◽  
Parasite Populations

SUMMARYDevelopments in the study of the ecology of helminth parasites of freshwater fishes over the last half century are reviewed. Most research has of necessity been field based and has involved the search for patterns in population and community dynamics that are repeatable in space and time. Mathematical models predict that under certain conditions host and parasite populations can attain equilibrial levels through operation of regulatory factors. Such factors have been identified in several host-parasite systems and some parasite populations have been shown to persist over long time-periods. However, there is no convincing evidence that fish parasite populations are stable and regulated since in all cases alternative explanations are equally acceptable and it appears that they are non-equilibrial systems. It has proved particularly difficult to detect replicable patterns in parasite communities. Inter-specific competition, evidenced by functional and numerical responses, has been detected in several communities but its occurrence is erratic and its significance unclear. Some studies have failed to find any nested patterns in parasite community structure and richness, whereas others have identified such patterns although they are seldom constant over space and time. Departures from randomness appear to be the exception and then only temporary. It appears that parasite communities are non-equilibrial, stochastic assemblages rather than structured and organized.

scholarly journals Species richness and diversity in shrub savanna using ordinary kriging

2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Diversity Index ◽  
Spatial Models ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Species Richness And Diversity ◽  
Number Of Species

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.

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