Helminth communities in the burrowing toad, Rhinella fernandezae, from Northeastern Argentina
TL;DR: The main goals of this study were to determine the richness and diversity of helminth parasites of Rhinella fernandezae at the component and infracommunity levels and determine the ecological implications of different biotic and abiotic factors.
Abstract: The main goals of this study were to determine the richness and diversity of helminth parasites of Rhinella fernandezae at the component and infracommunity levels and determine the ecological implications of different biotic and abiotic factors. Specimens were collected near the city of Corrientes, Corrientes Province, Argentina. Prevalence of infection was 94% in the specimens examined (n = 65). The helminth component community in R. fernandezae in this area was comprised a total of 22 species. Of all helminth species, only three (Catadiscus inopinatus, Cosmocerca podicipinus and C. parva) were dominant (importance value: I > 1.0) in the community. The most abundant species were B. tetracotyloides (d = 0.43) among the larvae and C. podicipinus (d = 0.09) among adult worms. At the infracommunity level, the mean individual species richness (2.28 ± 1.48) (mean ± SD) was no more than 3 helminth species per infected host; the diversity and equitability of helminths were 0.23 ± 0.21 and 0.48 ± 0.38, respectively. The host body size was the main factor in determining the parasite abundance. Species richness was significantly and positively correlated with host body size. The parasite helminth species predominantly showed an overdispersed pattern of distribution. Helminth species showed two negative and significant pairs of covariation and one significant pair of association (P < 0.05). R. fernandezae has a wide variety of parasites relating to the host microhabitat, mobility and feeding habits.
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729 citations
01 Jan 2009
TL;DR: UNESP - Univ de Estadual Paulista, Campus de Botucatu, Instituto de Biociencias, Departamento de Parasitologia, Botucatus, Sao Paulo, Brazil
Abstract: Fifteen specimens of bufonid toad Rhinella icterica (Spix, 1824), 7 males and 8 females, collected in the municipality of Botucatu, Sao Paulo State, Brazil, from March 2002 to January 2003, were examined for helminth parasites. All toads were infected with at least one parasite species (overall prevalence = 100%). Five helminth species were found, including four nematode species, Rhabdias fuelleborni Travassos, 1926, Oswaldocruzia subauricularis (Rudolphi, 1819), gen. sp. no identified Cosmocercidae Travassos, 1925 and larvae of Physaloptera Rudolphi, 1819, and one acanthocephalan species, Acanthocephalus saopaulensis Smales, 2007. Rhabdias fuelleborni and A. saopaulensis were the most abundant species. Except for Physalopteridae larvae, all helminths occur in high prevalence (> 70%). All helminth species presented a distribution toward to more aggregated pattern in these host samples.
25 citations
TL;DR: Results showed that diets and mobility of the host and the local microhabitat conditions play an important role in parasitic infections of toads, and that host body size was the main factor in determining the infrapopulation structure of helminth parasites.
Abstract: The goal of this study was to evaluate the relative influence of terrestrial habits, season, and host body size on the species richness and abundance of helminth parasites in the toad Melanophryniscus klappenbachi, for which a greater abundance of nematode parasites was expected. A total of 90 toads were collected in the Chaco Province, Argentina. The helminth community found in infected toads included 17 taxa and was dominated particularly by larval parasites. Contrary to our expectations, nematode species showed lower values of infection parameters. Infected toads harbored a maximum of seven species, and the mean helminth richness was 3.16 ± 1.66 species per infected toads. Season played a significant effect on determining the species richness and abundance of the parasite infracommunity. Similarly, the prevalence of infection of several helminth species (8/47%) varied greatly over time. Host body size was the main factor in determining the infrapopulation structure of helminth parasites. Species richness was significantly and negatively correlated with host body size. Strong associations were observed mainly between larvae of some species. The transmission strategies of parasites suggest that this bufonid acquires infections through direct contact with larval parasites from aquatic and terrestrial habitats and by ingestion of infective larvae. The characteristic of the host tegument, such as the presence of alkaloids, could significantly contribute to the low occurrence of infection by skin-penetrating nematodes. Results also showed that diets and mobility of the host and the local microhabitat conditions play an important role in parasitic infections of toads.
21 citations
Cites background from "Helminth communities in the burrowi..."
...As demonstrated in a previous research (Hamann et al. 2013b) in amphibian hosts from a variety of habitats in Corrientes, Argentina, the diets and mobility of the host and the local microhabitat conditions may have considerable influence on the trematode parasite communities and are important…...
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...With regard to amphibian body size, several authors suggest that this variable positively influences species richness and abundance of the helminth parasites (Muzzall 1991; McAlpine 1997; Bolek and Coggins 2000; Yoder and Coggins 2007; Ibrahim 2008; Hamann et al. 2012, 2013a)....
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...…amphibians are depauperate and isolationist (Bolek and Coggins 2003; Yoder and Coggins 2007; Ibrahim 2008), while others consider no fixed pattern, i.e., communities could be arranged along an axis from isolationist communities to interactive communities (Luque et al. 2005; Hamann et al. 2013a)....
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...…region (Bolek and Coggins 2003; Yoder and Coggins 2007) and tropical region (Bursey et al. 2001; Goldberg and Bursey 2003; Luque et al. 2005; Ibrahim 2008; Lux Hoppe et al. 2008; Pinhão et al. 2009; Santos and Amato 2010; Hamann et al. 2013a), where nematode species dominate the community....
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...…helminth community of bufonids (e.g., R. fernandezae) from Corrientes, Argentina, the latter showed an equal richness of nematodes and trematodes but was better represented by skinpenetrating nematodes (e.g., Cosmocerca podicipinus Baker & Vaucher, 1984) as dominant species (Hamann et al. 2013a)....
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TL;DR: The results suggest that the amount of rainfall and associated humidity affects the distribution and development of the parasite fauna of this toad.
Abstract: The present study describes the diversity of helminth parasites of Rhinella major (Anura: Bufonidae) in relation to their body size in 4 subhumid vs. semiarid sampling sites from the Argentine Chaco region. Helminths were found in 81% of the specimens examined (n = 85). Fifteen species (13 in subhumid and 7 in semiarid areas) of helminth parasites were found, and most of them were nematodes. Parasites were found in all the examined organs, with highest prevalence and intensity in the digestive tract. Parasite transmission to the toad host occurs by skin penetration or oral ingestion. Maximum helminth richness ranged between 2 and 4 species per infected toad. The most abundant species was Aplectana hylambatis . Body size of the host was the main factor in determining parasite richness. The helminth parasite fauna was rather different in hosts from subhumid vs. semiarid sites, but the dominant ( Aplectana hylambatis ) and codominant species ( Cylindrotaenia sp. and Rhabdias elegans ) were the same. Mean species richness and mean species diversity of helminths were significantly different between the zones. These results suggest that the amount of rainfall and associated humidity affects the distribution and development of the parasite fauna of this toad.
18 citations
References
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Journal Article•
TL;DR: The Mathematical Theory of Communication (MTOC) as discussed by the authors was originally published as a paper on communication theory more than fifty years ago and has since gone through four hardcover and sixteen paperback printings.
Abstract: Scientific knowledge grows at a phenomenal pace--but few books have had as lasting an impact or played as important a role in our modern world as The Mathematical Theory of Communication, published originally as a paper on communication theory more than fifty years ago. Republished in book form shortly thereafter, it has since gone through four hardcover and sixteen paperback printings. It is a revolutionary work, astounding in its foresight and contemporaneity. The University of Illinois Press is pleased and honored to issue this commemorative reprinting of a classic.
15,525 citations
Book•
01 Jan 1948
TL;DR: The Mathematical Theory of Communication (MTOC) as discussed by the authors was originally published as a paper on communication theory more than fifty years ago and has since gone through four hardcover and sixteen paperback printings.
Abstract: Scientific knowledge grows at a phenomenal pace--but few books have had as lasting an impact or played as important a role in our modern world as The Mathematical Theory of Communication, published originally as a paper on communication theory more than fifty years ago. Republished in book form shortly thereafter, it has since gone through four hardcover and sixteen paperback printings. It is a revolutionary work, astounding in its foresight and contemporaneity. The University of Illinois Press is pleased and honored to issue this commemorative reprinting of a classic.
10,215 citations
Book•
01 Jan 2004TL;DR: In this paper, the authors focus on the pressure humanity is placing on the natural world, and on the continued ability of ecosystems to deliver the services on which we all depend, and develop strategies to ameliorate its impact.
Abstract: Summary As prehistoric cave paintings illustrate, our species has had an enduring appreciation of the variety and abundance of life on Earth. Today, however, concern is focused on the pressure humanity is placing on the natural world, and on the continued ability of ecosystems to deliver the services on which we all depend. To understand the extent of this ‘biodiversity crisis’ and develop strategies to ameliorate its impact, it is essential to be able to accurately measure biological diversity (a term often contracted to biodiversity) and make informed predictions about how and why this diversity varies over space and time.
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TL;DR: Suggestions for various terms used by parasitologists when describing the ecology of parasites are provided in an attempt to foster consistent use and to make terms used in parasite ecology easier to interpret for those who study free-living organisms.
Abstract: We consider 27 population and community terms used frequently by parasitologists when describing the ecology of parasites. We provide suggestions for various terms in an attempt to foster consistent use and to make terms used in parasite ecology easier to interpret for those who study free-living organisms. We suggest strongly that authors, whether they agree or disagree with us, provide complete and unambiguous definitions for all parameters of their studies.
6,400 citations
"Helminth communities in the burrowi..." refers methods in this paper
...The infection prevalence, intensity, and abundance were calculated for helminths following Bush et al. (1997)....
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Book•
01 Jan 1984
4,197 citations
"Helminth communities in the burrowi..." refers background in this paper
...Community richness and diversity were estimated through the following: total number of helminth species (= richness), Shannon index (H ′) (Shannon & Weaver 1949), and evenness (J ′) asH ′/H ′ maximum (Zar 2010)....
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