scholarly journals Helminth community dynamics in a population of Pseudopaludicola pocoto (Leptodactylidae: Leiuperinae) from Northeast-Brazilian

2018 ◽  
Vol 55 (4) ◽  
pp. 292-305 ◽  
Author(s):  
C. De S. Silva ◽  
R. W. Ávila ◽  
D. H. Morais
Keyword(s):  
Rainy Season ◽  
Community Dynamics ◽  
Environmental Changes ◽  
Infection Intensity ◽  
Environmental Parameters ◽  
Parasite Community ◽  
Helminth Community ◽  
Parasite Communities ◽  
Low Latitudes ◽  
Dry And Rainy Seasons

Abstract Climatic variation in low latitudes influences the dynamics and structure of parasite communities. Environmental changes caused by dry and rainy seasons alter prevalence and abundance of endoparasite communities. In addition to providing a list of the helminth species associated with the swamp frog Pseudopaludicola pocoto, this study aimed to investigate the effects of rainfall and temperature on parasitological descriptors of helminths associated with P. pocoto in an area of the semiarid zone. A total of 817 swamp frog specimens were collected between 2013 and 2017, with four sampling expeditions during the dry season and four during the rainy season. Environmental parameters of temperature and rainfall were compared to the parasitological descriptors of prevalence, abundance and mean infection intensity of the parasite community using a multivariate linear regression. A richness of eight parasite species was identified, including Nematoda (Rhabdias sp., Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp., Brevimulticaecum sp., Spiroxys sp. and unidentified nematode) and Acanthocephala (cystacanths). Rainfall levels had a significant effect on the infection intensity of Rhabdias sp. being the presence of this species higher during the rainy season, whereas no influence of temperature was observed on the helminth community.

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 Bovine tuberculosis disturbs parasite functional trait composition in African buffalo

2019 ◽  
Vol 116 (29) ◽  
pp. 14645-14650 ◽  
Author(s):  
Brianna R. Beechler ◽  
Kate S. Boersma ◽  
Peter E. Buss ◽  
Courtney A. C. Coon ◽  
Erin E. Gorsich ◽  
...  
Keyword(s):  
Community Composition ◽  
Bovine Tuberculosis ◽  
Community Dynamics ◽  
Parasite Community ◽  
Functional Trait ◽  
Taxonomic Composition ◽  
African Buffalo ◽  
Emerging Infections ◽  
Parasite Communities ◽  
Parasite Richness

Novel parasites can have wide-ranging impacts, not only on host populations, but also on the resident parasite community. Historically, impacts of novel parasites have been assessed by examining pairwise interactions between parasite species. However, parasite communities are complex networks of interacting species. Here we used multivariate taxonomic and trait-based approaches to determine how parasite community composition changed when African buffalo (Syncerus caffer) acquired an emerging disease, bovine tuberculosis (BTB). Both taxonomic and functional parasite richness increased significantly in animals that acquired BTB than in those that did not. Thus, the presence of BTB seems to catalyze extraordinary shifts in community composition. There were no differences in overall parasite taxonomic composition between infected and uninfected individuals, however. The trait-based analysis revealed an increase in direct-transmitted, quickly replicating parasites following BTB infection. This study demonstrates that trait-based approaches provide insight into parasite community dynamics in the context of emerging infections.

scholarly journals Seasonal variability of the composition and structure of parasite communities of red porgy, Pagrus pagrus (Perciformes: Sparidae) off Brazil

2015 ◽  
Vol 52 (3) ◽  
pp. 236-243 ◽  
Author(s):  
I. A. Soares ◽  
J. L. Luque
Keyword(s):  
Rainy Season ◽  
Dominant Species ◽  
Parasite Community ◽  
Reproductive Activity ◽  
Metazoan Parasites ◽  
Parasite Communities ◽  
Four Seasons ◽  
Composition And Structure ◽  
Pagrus Pagrus ◽  
Autumn And Winter

Abstract A study of seasonal variation of metazoan parasite community of Pagrus pagrus was conducted between January and December 2012. Two hundred forty specimens of Pagrus pagrus were collected in four seasons (autumn and winter in dry season and spring and summer in rainy season) from off the state of Rio de Janeiro, Brazil. Twenty one species of metazoan parasites were found, with larvae of Hysterothylacium sp. being the dominant species. The highest values of prevalence and abundance was during the rainy season with peak prevalence of monogeneans and nematodes, period of action of the South Atlantic Central Waters (SACW) and reproductive activity of the host, suggesting that the sasonal variation in the parasites community was influenced for these phenomena.

Spatial variation in helminth community structure in the red-legged partridge (Alectoris rufaL.): effects of definitive host density

Parasitology ◽  
2004 ◽  
Vol 129 (1) ◽  
pp. 101-113 ◽  
Author(s):  
C. CALVETE ◽  
J. A. BLANCO-AGUIAR ◽  
E. VIRGÓS ◽  
S. CABEZAS-DÍAZ ◽  
R. VILLAFUERTE
Keyword(s):  
Parasite Community ◽  
Local Scale ◽  
Helminth Species ◽  
Population Abundance ◽  
Helminth Community ◽  
Intensity Of Infection ◽  
Component Community ◽  
Abundance Index ◽  
Mean Intensity ◽  
Parasite Communities

Parasite community ecology has recently focused on understanding the forces structuring these communities. There are few surveys, however, designed to study the spatial repeatability and predictability of parasite communities at the local scale in one host. The purpose of our study was to address the relationship between infracommunity and component community richness, and to describe spatial variations on the local scale, of helminth parasite communities in an avian host, the red-legged partridge (Alectoris rufa). We sampled 235 wild partridges from 8 separate localities, with different partridge population densities, in the Ciudad Real and Toledo provinces of central Spain, and we determined their overall and intestinal helminth species. We found that habitat variables (mean temperature and land use) were not significantly associated with any component community. The partridge population abundance index was directly correlated with the prevalence and mean intensity of infection but not with component community species richness. There was a curvilinear relationship between infracommunity and component community species richness, as well as negative interspecific associations, for the helminth species assemblage parasitizing the intestine. A nestedness/anti-nestedness pattern, considered as part of a continuum, was associated with prevalence, mean intensity and partridge population abundance index, but not with component community richness. Increases in the partridge population abundance index and the prevalence and mean intensity of infection were associated with increases in helminth community nestedness. Although negative interactions between helminth species could not be ruled out as forces structuring helminth communities, our results suggest that parasite community structure in the red-legged partridge was primarily determined by the extrinsic influence of parasite habitat heterogeneity and its amplification of the differing probabilities of colonization of parasite species.

scholarly journals Spatial and temporal variation and the influence of environmental parameters in a fish community in the Una River, Paraíba do Sul Valley, São Paulo

2020 ◽  
Vol 15 (7) ◽  
pp. 1
Author(s):  
Juliano Rodrigues Honorio ◽  
Itamar Alves Martins
Keyword(s):  
Rainy Season ◽  
Fish Community ◽  
Environmental Parameters ◽  
Sampling Period ◽  
Spatial And Temporal Variation ◽  
Fish Species Composition ◽  
Study Sites ◽  
Partial Redundancy Analysis ◽  
Partial Redundancy ◽  
Dry And Rainy Seasons

Understanding of aspects of the structure of ichthyological communities and how these relate to the environment and its natural variation has been one of the principal objectives of ecological studies conducted in freshwater environments. The objective of this study was to evaluate the relationship between fish species composition in the Una River and environmental variables during dry and rainy seasons. Data collection was done along three stretches of the main channel of the Una River between April 2016 and March 2017. In general, the riverbed presented a high degree of silting in all study sites. A total of 1,534 fish specimens from thirty species were collected. There was greater richness and abundance of species during the rainy season in all sampled areas. A Partial Redundancy Analysis (pRDA) showed a significant correlation between the fish community, substrate composition, and concentrations of dissolved oxygen in the water. The qualitative structure of the ichthyofauna indicated a greater association with environmental structure than with seasonality, since there was a clear tendency for the three stretches of river to group together independent of the sampling period. There were no significant differences between the indices of diversity registered for the dry and rainy seasons. This is due to the dominance of the species Astyanax aff. bimaculatus (two spot Astyanax | lambari-do-rabo-amarelo) and Hypostomus cf. luetkeni (armoured catfish | cascudo), which represented more than half of the collected specimens during the rainy season.

scholarly journals Helminth community structure and diet of three Afrotropical anuran species: a test of the interactive-versus-isolationist parasite communities hypothesis

Web Ecology ◽  
2011 ◽  
Vol 11 (1) ◽  
pp. 11-19 ◽  
Author(s):  
G. C. Akani ◽  
L. Luiselli ◽  
C. C. Amuzie ◽  
G. N. Wokem
Keyword(s):  
Interspecific Competition ◽  
Dietary Habits ◽  
Parasite Community ◽  
Helminth Community ◽  
Parasite Communities ◽  
Anuran Species ◽  
Infection Parameters ◽  
Parasitological Survey ◽  
Competition For Food ◽  
Species Specific

Abstract. The interactive-versus-isolationist hypothesis predicts that parasite communities should be depauperated and weakly structured by interspecific competition in amphibians. A parasitological survey was carried out to test this hypothesis using three anuran species from Nigeria, tropical Africa (one Bufonidae; two Ranidae). High values of parasite infection parameters were found in all three species, which were infected by nematodes, cestodes and trematodes. Nonetheless, the parasite communities of the three anurans were very depauperated in terms of number of species (4 to 6). Interspecific competition was irrelevant in all species, as revealed by null models and Monte Carlo permutations. Cluster analyses revealed that, in terms of parasite community composition, the two Ranidae were similar, whereas the Bufonidae was more different. However, when prevalence, intensity, and abundance of parasites are combined into a multivariate analysis, each anuran species was clearly spaced apart from the others, thus revealing considerable species-specific differences in terms of their parasite communities. All anurans were generalists and probably opportunistic in terms of dietary habits, and showed no evidence of interspecific competition for food. Overall, our data are widely consistent with expectations driven from the interactive-versus-isolationist parasite communities hypothesis.

STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk
Keyword(s):  
Land Use ◽  
Malaria Vector ◽  
Rainy Season ◽  
Dry Season ◽  
Physical Factors ◽  
Mosquito Vector ◽  
Anopheles Species ◽  
Commercial Farming ◽  
Study Results ◽  
Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

Interactions between parasites of the cockleAustrovenus stutchburyi: hitch-hikers, resident-cleaners, and habitat-facilitators

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 247-255 ◽  
Author(s):  
T. L. F. LEUNG ◽  
R. POULIN
Keyword(s):  
New Zealand ◽  
Parasite Species ◽  
Infection Intensity ◽  
Positive Association ◽  
Parasite Community ◽  
Transmission Route ◽  
Interspecific Associations ◽  
Number Of Factors ◽  
Austrovenus Stutchburyi ◽  
Rate Of Accumulation

The patterns of association between parasites within a particular host are determined by a number of factors. One of these factors is whether or not infection by one parasite influences the probability of acquiring other parasite species. This study investigates the pattern of association between various parasites of the New Zealand cockleAustrovenus stutchburyi. Hundreds of cockles were collected from one locality within Otago Harbour, New Zealand and examined for trematode metacercariae and other symbionts. Two interspecific associations emerged from the study. First, the presence of the myicolid copepodPseudomyicola spinosuswas positively associated with higher infection intensity by echinostomes. The side-effect of the copepod's activities within the cockle is suggested as the proximate mechanism that facilitates infection by echinostome cercariae, leading to a greater rate of accumulation of metacercariae in cockles harbouring the copepod. Second, a positive association was also found between infection intensity of the metacercariae of foot-encysting echinostomes and that of gymnophallid metacercariae. This supports earlier findings and suggests that the gymnophallid is a hitch-hiker parasite because, in addition to the pattern of positive association, it (a) shares the same transmission route as the echinostomes, and (b) unlike the echinostomes, it is not capable of increasing the host's susceptibility to avian predation. Thus, both active hitch-hiking and incidental facilitation lead to non-random infection patterns in this parasite community.

scholarly journals Transpiration and stomatal resistance variations of perennial tropical crops under soil water availability conditions and water deficit

2007 ◽  
Vol 50 (2) ◽  
pp. 225-230 ◽  
Author(s):  
José Ozinaldo Alves de Sena ◽  
Humberto Actis Zaidan ◽  
Paulo Roberto de Camargo e Castro
Keyword(s):  
Water Availability ◽  
Rainy Season ◽  
Rubber Tree ◽  
Psidium Guajava ◽  
Stomatal Resistance ◽  
Paullinia Cupana ◽  
Tropical Crops ◽  
Water Transpiration ◽  
Coffea Arabica L ◽  
Dry And Rainy Seasons

During the dry and rainy seasons, determinations of stomatal resistance and transpiration of five tropical crops were carried out: guarana (Paullinia cupana Kunth), coffee (Coffea arabica L.), cashew (Anacardium occidentale L.), guava (Psidium guajava L.) and rubber (Hevea brasiliensis Muell. - Arg.) trees. Experimental design was done at randomized complete blocks with five replications. During the dry season there was a decrease in values of stomatal resistance in the following order: guarana > coffee> cashew> guava > rubber, with values from 2.5 to 30.0 s.cm-1. During the rainy season the stomatal resistance values varied from 1.5 to 3.0 s.cm-1. The guarana and coffee crops showed higher resistance to water transpiration when compared to other crops. During the rainy season, the rubber tree continued to present lower stomatal resistance and, consequently, higher transpiration.

Helminth Parasite Communities of the Water-rat, Hydromys chrysogaster, from Queensland

1997 ◽  
Vol 24 (4) ◽  
pp. 445 ◽  
Author(s):  
L. R. Smales ◽  
T. H. Cribb
Keyword(s):  
Bimodal Distribution ◽  
Helminth Fauna ◽  
Helminth Community ◽  
Parasite Communities ◽  
Far North ◽  
Core Species ◽  
Helminth Communities ◽  
Eastern Australia ◽  
Hydromys Chrysogaster ◽  
High Diversity

The helminth fauna from 124 water-rats, Hydromys chrysogaster, collected from 33 localities in Queensland was analysed. A total of 45 species of helminths was found, comprising 2 acanthocephalans, 2 cestodes, 13 nematodes and 28 trematodes. The helminth community of the water-rats in the region north of latitude 18˚ (far north) was different from that of water-rats south of 18˚ (central); Sorensen’s Index 45·8% similarity, whereas Holmes and Podesta’s Index gave 32·1% similarity. Comparisons with data from water-rats from southern and Tasmanian regions showed that they were different from each other and from both Queensland regions. The helminth communities were characterised by high diversity, dominated by trematodes in the central and Tasmanian regions, but with nematodes becoming more prominent in the far northern and southern regions. No core or secondary species were found in the Queensland helminth communities, the southern community was suggestive of a bimodal distribution and the Tasmanian had two core species. A checklist of helminth species occurring in water-rats from eastern Australia is provided.

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