scholarly journals Raillietiella mottae (Pentastomida: Raillietiellidae) parasitizing four species of Gekkota lizards (Gekkonidae and Phyllodactylidae) in the Brazilian Caatinga

2018 ◽  
Vol 55 (2) ◽  
pp. 140-145 ◽  
Author(s):  
V. F. Lima ◽  
S. V. Brito ◽  
J. A. Araujo Filho ◽  
D. A. Teles ◽  
S. C. Ribeiro ◽  
...  
Keyword(s):  
Body Size ◽  
New Host ◽  
Parasite Abundance ◽  
Host Body ◽  
Host Sex ◽  
New Host Records ◽  
Host Body Size

Summary We tested the role of sex, size, and mass of the lizards Phyllopezus pollicaris, Gymnodactylus geckoides, Hemidactylus agrius, Lygodactylus klugei, and Hemidactylus brasilianus on the rates of pentastomid infection in the Brazilian Caatinga. We collected 355 individuals of these five species, of which four (prevalence of infection: P. pollicaris 15.9 %, G. geckoides 1.4 %, H. agrius 28.57 %, and H. brasilianus 4.16 %) were infected by Raillietiella mottae. Parasite abundance was influenced by host body size and mass only in P. pollicaris. Host sex did not influence the abundance of parasites in any species. Hemidactylus agrius, G. geckoides, and H. brasilianus are three new host records for pentastomids.

scholarly journals Infection patterns of helminths in Norops brasiliensis (Squamata, Dactyloidae) from a humid forest, Northeastern Brazil and their relation with body mass, sex, host size, and season

2019 ◽  
Vol 56 (2) ◽  
pp. 168-174 ◽  
Author(s):  
D. M. Amorim ◽  
R. W. Ávila
Keyword(s):  
Body Size ◽  
Ecological Factors ◽  
Parasite Load ◽  
Helminth Fauna ◽  
Northeastern Brazil ◽  
Rainfall Regime ◽  
New Host ◽  
Humid Forest ◽  
Host Sex ◽  
New Host Records

SummaryClimatic and ecological factors can influence the parasite load of a host. Variation in rainfall, body size, and sex of the hosts may be related to the abundance of parasites. This study investigated the helminth fauna associated with a population of Norops brasiliensis, together with the effect of host biology (sex, body size, and mass) and variation in rainfall regime on the abundance of helminths. Species of three groups of endoparasites were found (Nematoda, Cestoda, and Trematoda), with nematodes as the most representative taxa with eight species, prevalence of 63.2 %, mean intensity of 4.0 ± 0.58 (1 – 25), and mean abundance of 2.66 ± 0.44 (0 – 25). Nine helminth species are new host records for N. brasiliensis. The nematode Rhabdias sp. had the highest prevalence (53.3 %). There was no significant relationship between abundance of the trematode Mesocoelium monas and host sex or season, although the abundance of this parasite increased significantly with host body size and mass, while abundance of nematodes was related to season and host mass. This study increases the knowledge about the diversity of helminth fauna associated with N. brasiliensis, revealing infection levels of hosts from northeastern Brazil.

Helminths infecting the parthenogenetic whiptail lizard Cnemidophorus nativo in a restinga habitat of Bahia State, Brazil

2004 ◽  
Vol 78 (4) ◽  
pp. 323-328 ◽  
Author(s):  
V.A. Menezes ◽  
D. Vrcibradic ◽  
J.J. Vicente ◽  
G.F. Dutra ◽  
C.F.D. Rocha
Keyword(s):  
Body Size ◽  
North America ◽  
Environmental Factors ◽  
Single Species ◽  
Helminth Species ◽  
Infection Rates ◽  
Coastal Site ◽  
New Host ◽  
New Host Records ◽  
Host Body Size

AbstractA sample of 101 specimens of the unisexual whiptail lizard Cnemidophorus nativo (Squamata; Teiidae) from a coastal site in Bahia State, Brazil were examined for the presence of endoparasites. Of these, 35 (34.7%) harboured helminths. Six helminth species were recovered from C. nativo, including five nematodes (Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia, Skrjabinelazia intermedia and Parapharyngodon sp., and one cestode (Oochoristica ameivae), all representing new host records. Most lizards were infected by a single species of helminth and none by more than three. Infection rates were neither significantly influenced by host body size nor by environmental factors. The results are compared with data from studies on other whiptail species in both South and North America.

Intraspecific patterns of ectoparasite abundances on Paraguayan bats: effects of host sex and body size

2008 ◽  
Vol 24 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Steven J. Presley ◽  
Michael R. Willig
Keyword(s):  
Body Size ◽  
Important Determinant ◽  
Social Groups ◽  
Total Abundance ◽  
Host Body ◽  
Host Sex ◽  
Direction Of Effects ◽  
Taxonomic Affiliation ◽  
Host Body Size ◽  
Stochastic Extinction

Abstract:Although levels of parasitism can vary greatly among individual bats of the same species, little is known about the characteristics of hosts that affect such variation. Bats were captured via mist nets from June 1995 to July 1997 from 28 localities throughout Paraguay. Over 17 500 ectoparasites were collected from 2909 bats; however, analyses of ectoparasite abundance were restricted to more abundant taxa of host and ectoparasite. We quantified the abundances of 29 taxa of ectoparasite on 19 species of bat host, as well as total abundance of ectoparasites regardless of taxonomic affiliation for 22 species of bat from Paraguay. The effects of host sex and host body size on these estimates of ectoparasite abundance were evaluated separately for each species of host. Ectoparasites did not respond consistently to host body size: ectoparasite abundance increased with host body size in 12 instances and decreased with host body size in 11 instances. Regardless of the existence or direction of effects of host body size on ectoparasite abundance, female hosts generally harboured more ectoparasites than did male hosts. Differences in host quality associated with the sex of bats, especially those related to behaviour, may be a more important determinant of ectoparasite abundance than are differences in size. Opportunities for host transfer are critical for species persistence of ectoparasites; consequently, ectoparasite populations on host individuals that form social groups or colonies should be larger, less prone to stochastic extinction, and have greater opportunity for speciation.

The evolution of body size in the Monogenea: the role of host size and latitude

1996 ◽  
Vol 74 (4) ◽  
pp. 726-732 ◽  
Author(s):  
Robert Poulin
Keyword(s):  
Body Size ◽  
Interspecific Variation ◽  
Host Size ◽  
Independent Contrasts ◽  
Related Factors ◽  
Host Body ◽  
Phylogenetically Independent Contrasts ◽  
Using Data ◽  
Host Body Size

Monogeneans form a diverse group of parasitic platyhelminths that show substantial interspecific variation in body size, though this variation remains largely unexplained. The relationships between monogenean body size and both host body size and latitude were examined in comparative analyses using data from 613 monogenean species. First, phylogenetically independent contrasts among 39 monogenean families revealed no relationship between host size and parasite size. However, large parasite size was consistently associated with high latitude, suggesting that larger body size in monogeneans may result more from external factors such as temperature than from host-related factors. The potential effects of other variables (site of attachment on the host, host taxonomy, and type of aquatic habitat) could not be assessed in the analysis. Second, analyses among genera within families failed to show any consistent relationships between monogenean body size and either host size or latitude. The results of this study suggest that latitude had an evolutionary influence on monogenean body size, though this may be only visible in comparisons among higher taxonomic levels, and that monogenean body size has not simply adjusted to host body size following host-switching events.

Helminths associated with Norops fuscoauratus (Squamata, Dactyloidae) in highland marshes of the Brazilian semi-arid

2020 ◽  
Vol 94 ◽  
Author(s):  
J.M. dos Santos Mesquita ◽  
S.S. de Oliveira ◽  
R. Perez ◽  
R.W. Ávila
Keyword(s):  
Body Size ◽  
Neotropical Region ◽  
Intensity Of Infection ◽  
New Host ◽  
Mean Intensity ◽  
Parasite Richness ◽  
Relationship Of ◽  
New Host Records ◽  
Host Body Size ◽  
Semi Arid

Abstract Helminthological studies may contribute with valuable information on host biology and conservation. Herein, we provide new data on helminths infecting the lizard Norops fuscoauratus, testing one of the factors considered most important in parasitic ecology: host size. We analysed 25 specimens of N. fuscoauratus from three highland marshes in the Brazilian semi-arid. Eight taxa of helminths belonging to Nematoda, Trematoda and Acanthocephala were found. Physaloptera sp. showed the higher prevalence (40%), with a mean intensity of infection of 3.3 ± 1.46 (1–16) and mean abundance 1.32 ± 0.65 (0–16). Norops fuscoauratus represents four new host records for the helminths Cyrtosomum sp., Pharyngodon travassosi, Strongyloides sp. and Centrorhynchus sp. There is no relationship of host body size (P = 0.79) and mass (P = 0.50) with parasite richness. In addition, the present study contributes to the knowledge of the parasitic fauna of N. fuscoauratus and the Neotropical region.

The role of ecological opportunity in shaping host–parasite networks

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1452-1460
Author(s):  
Elvira D'Bastiani ◽  
Karla M. Campião ◽  
Walter A. Boeger ◽  
Sabrina B. L. Araújo
Keyword(s):  
Body Size ◽  
Theoretical Models ◽  
Interaction Networks ◽  
Ecological Opportunity ◽  
Host Body ◽  
Seasonally Flooded ◽  
Brazilian Pantanal ◽  
Host Parasite ◽  
Host Body Size

AbstractDespite the great interest to quantify the structure of host–parasite interaction networks, the real influence of some factors such as taxonomy, host body size and ecological opportunity remains poorly understood. In this paper, we investigate the general patterns of organization and structure of interactions in two anuran–parasite networks in the Brazilian Pantanal (seasonally flooded environment) and Atlantic Forest (non-flooded forest). We present theoretical models to test whether the structures of these host–parasite interaction networks are influenced by neutrality, host taxonomy and host body size. Subsequently, we calculated metrics of connectance, nestedness and modularity to characterize the network structure. We demonstrated the structure networks were influenced mainly by body size and taxonomy of the host. Moreover, our results showed that the seasonally flooded environment present networks with higher connectance/nestedness and lower modularity compared to the other environment. The results also suggest that seasonal floods may promote ecological opportunities for new species associations.

scholarly journals Host allometry influences the evolution of parasite host-generalism: theory and meta-analysis

2017 ◽  
Vol 372 (1719) ◽  
pp. 20160089 ◽  
Author(s):  
Josephine G. Walker ◽  
Amy Hurford ◽  
Jo Cable ◽  
Amy R. Ellison ◽  
Stephen J. Price ◽  
...  
Keyword(s):  
Body Size ◽  
Host Species ◽  
Meta Analysis ◽  
Transmission Risk ◽  
New Host ◽  
Host Body ◽  
Biological Interest ◽  
Single Host ◽  
Future Work ◽  
Host Body Size

Parasites vary widely in the diversity of hosts they infect: some parasite species are specialists—infecting just a single host species, while others are generalists, capable of infecting many. Understanding the factors that drive parasite host-generalism is of basic biological interest, but also directly relevant to predicting disease emergence in new host species, identifying parasites that are likely to have unidentified additional hosts, and assessing transmission risk. Here, we use mathematical models to investigate how variation in host body size and environmental temperature affect the evolution of parasite host-generalism. We predict that parasites are more likely to evolve a generalist strategy when hosts are large-bodied, when variation in host body size is large, and in cooler environments. We then explore these predictions using a newly updated database of over 20 000 fish–macroparasite associations. Within the database we see some evidence supporting these predictions, but also highlight mismatches between theory and data. By combining these two approaches, we establish a theoretical basis for interpreting empirical data on parasites' host specificity and identify key areas for future work that will help untangle the drivers of parasite host-generalism. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

Explaining variability in parasite aggregation levels among host samples

Parasitology ◽  
2013 ◽  
Vol 140 (4) ◽  
pp. 541-546 ◽  
Author(s):  
ROBERT POULIN
Keyword(s):  
Body Size ◽  
Strong Relationship ◽  
Host Susceptibility ◽  
Helminth Parasites ◽  
Susceptibility To Infection ◽  
Host Body ◽  
Parasite Aggregation ◽  
Using Data ◽  
Species Specific ◽  
Host Body Size

SUMMARYAggregated distributions among individual hosts are a defining feature of metazoan parasite populations. Heterogeneity among host individuals in exposure to parasites or in susceptibility to infection is thought to be the main factor generating aggregation, with properties of parasites themselves explaining some of the variability in aggregation levels observed among species. Here, using data from 410 samples of helminth parasites on fish hosts, I tested the contribution of (i) within-sample variation in host body size, taken as a proxy for variability in host susceptibility, and (ii) parasite taxon and developmental stage, to the aggregated distribution of parasites. Log-transformed variance in numbers of parasites per host was regressed against log mean number across all samples; the strong relationship (r2 = 0·88) indicated that aggregation levels are tightly constrained by mean infection levels, and that only a small proportion of the observed variability in parasite aggregation levels remains to be accounted for by other factors. Using the residuals of this regression as measures of ‘unexplained’ aggregation, a mixed effects model revealed no significant effect of within-sample variation in host body size or of parasite taxon or stage (i.e. juvenile versus adult) on parasite aggregation level within a sample. However, much of the remaining variability in parasite aggregation levels among samples was accounted for by the number of individual hosts examined per sample, and species-specific and study-specific effects reflecting idiosyncrasies of particular systems. This suggests that with most differences in aggregation among samples already explained, there may be little point in seeking universal causes for the remaining variation.

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