Phylum Nematomorpha

Bolek, Matthew G.; Schmidt‐Rhaesa, Andreas; Villalobos, Leonor Cristina de; Hanelt, Ben

doi:10.1016/b978-0-12-385026-3.00015-2

Cited by 31 publications

(55 citation statements)

References 77 publications

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“…Once worms emerge in an aquatic habitat from their definitive arthropod hosts, they mate and females deposit egg strings (Schmidt-Rhaesa 1997; Bolek et al 2015). Once hatched, larvae reside in the sediment where they are consumed and encyst in various aquatic animals.…”

Section: Discussionmentioning

confidence: 99%

“…This is particularly important because an ideal indicator host should maintain a parasitic infection for long periods of time, allowing investigators to track the occurrence of that parasite long after other stages of that parasite have disappeared from a particular geographic location. Additionally, the feeding behavior of snails on the bottom of aquatic habitats makes them ideal hosts to encounter gordiid larvae, which reside in these microhabitats (Hanelt et al 2001;Bolek et al 2015). As a result, snails are likely to come in contact with the microscopic and semi-sessile gordiid larvae more commonly than other invertebrates and vertebrates in aquatic habitats (Hanelt et al 2005).…”

Section: Introductionmentioning

confidence: 99%

“…This approach has allowed researchers to generate potential species distribution maps that can provide additional information in forming accurate predictions on potential intermediate, paratenic, definitive or reservoir hosts for specific species of parasites where such information is lacking (Haverkost et al 2010;Peterson et al 2002). This method is especially appealing for studying gordiids because virtually nothing is known about the distribution, life cycles or host use for most hairworm species (SchmidtRheasa et al 2003;Bolek et al 2015). While recent progress has been made in understanding the general life-cycle of hairworms, many questions regarding their paratenic and definitive host use in nature remain unanswered (Schmidt-Rhaesa 1997;Hanelt & Janovy 1999;Hanelt & Janovy 2003;Hanelt & Janovey 2004;Schmidt-Rhaesa et al 2003;Hanelt et al 2005;Schmidt-Rhaesa et al 2008;Bolek et al 2010;Hanelt et al 2012;Schmidt-Rhaesa 2013;Bolek et al 2013a;Bolek et al 2013b;Bolek et al 2015).…”

Section: Introductionmentioning

confidence: 99%

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Using Gordiid cysts to discover the hidden diversity, potential distribution, <br />and new species of Gordiids (Phylum Nematomorpha)

Harkins

Shannon

Papeş

et al. 2016

Zootaxa

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In this study, we sampled aquatic snails for the presence of hairworm cysts from 46 streams in Payne County, Oklahoma. Gordiid cysts were found at 70 % (32/46) of sites examined. Based on cyst morphology, we were able to identify three morphological types of gordiid cysts, including Paragordius, Gordius, and Chordodes/Neochordodes. Using our gordiid cyst presence data in conjunction with environmental variables, we developed an ecological niche model using Maxent to identify areas suitable for snail infections with gordiids. The model successfully predicted all presence localities of gordiid cysts in snails over a geographic area of 1,810 km 2 . We used this information, along with arthropod host infections and crowdsourcing, citizen scientists sampling for adult free-living worms during peak emergent times in areas predicted suitable by the model, to document Paragordius varius, Chordodes morgani, and a new species of gordiid (Gordius n. sp.). To our knowledge, this is the first ecological niche model attempted on such a narrow geographic scale (county level) that recovered known locations successfully. We provide new scanning electron micrographs and molecular data for these species. Our field data and ecological niche model clearly indicate that gordiid cysts are easy to detect in the environment and together these sampling techniques can be useful in discovering new species of gordiids, even in relatively well sampled areas for these cryptic parasites.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Using Gordiid cysts to discover the hidden diversity, potential distribution, <br />and new species of Gordiids (Phylum Nematomorpha)

Harkins

Shannon

Papeş

et al. 2016

Zootaxa

Self Cite

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“…A significant aspect of their mode of parasitism is that they induce an altered behavior in the host, causing in those that are terrestrial, a need to search for and enter water, in an attempt to release the parasites. This immersion can result in drowning (Bolek, Schmidt-Rhaesa, de Villalobos, & Hanelt, 2015;Cochran, Kinziger, & Poly, 1999;de Villalobos, Ortiz-Sandoval, & Habit, 2008; Hanelt, Thomas, & SchmidtRhaesa, 2005;Kinziger, Cochran, & Cochran, 2002;Ponton et al, 2006;Schmidt-Rhaesa, 1997;Schmidt-Rhaesa & Ehrmann, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…Studies on domesticated members of these so-called hairworms have indicated that the life cycle of gordiids involves five different life stages: (1) egg strings, (2) freeliving larvae, (3) parasitic cysts, (4) parasitic juveniles, and (5) dioecious or parthenogenetic free-living adults. The larvae of the Gordiida -being benthic, microscopic, and scarcely motile-survive from three days to a few weeks after hatching, and during that time have the capacity to infect hosts that are either paratenic or definitive (Bolek, Schmidt-Rhaesa, de Villalobos, & Hanelt, 2015;Schmidt-Rhaesa, 2012). Thus, the viability of the larval stage directly after hatching will determine the success in infection and overall survival.…”

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confidence: 99%

Analysis of the Infectivity of Chordodes Nobilii Larvae (Gordiida, Nematomorpha)

Achiorno

Villalobos

Ferrari

2016

RBT

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Abstract:The gordiids are freshwater representatives of the parasite phylum Nematomorpha that function as a link between aquatic and terrestrial ecosystems. In recent years, different ecotoxicologic studies have been made with the South-American gordiid species, Chordodes nobilii, that have demonstrated the capacity of this group to act as a bioindicator of contamination. Despite the Gordiida's ecologic relevance, further studies are still needed to elucidate different aspects of the biology of the class, and among those, the infective capacity, a parameter that can be evaluated by the infection index mean abundance (IIMA). A knowledge of the intrinsic variability in the infective capacity of C. nobilii would warrant priority in order to establish, the range of acceptable responses for normal or standard conditions in the laboratory, and, to compare the criteria among different assays. The objective of this study was to establish a baseline value for the infective capacity for C. nobilii larvae, under controlled laboratory conditions, by employing the IIMA as the evaluation parameter. To that end, we analyzed the infective capacity of C. nobilii larvae that had hatched from different strings of eggs laid in the laboratory by a total of 12 females. The C. nobilii adults were collected from streams within the Argentina Sauce Grande basin, between 2006 and 2009. Once in the laboratory, after mating, the females were placed in individual containers for oviposition. The egg strings obtained from each female were cut in 3 mm long segments; and when free larvae were observed, the segments (N= 90) were placed together with 30 Aedes aegypti larvae for evaluation of the gordiids' infective capacity. After 72 h, the mosquito larvae were observed by microscopy in order to quantify the C. nobilii larvae in body cavities. The IIMAs were calculated as the total number of C. nobilii larvae present divided by total number of A. aegypti larvae examined. For analysis of the IIMAs obtained, the data were grouped according to the female who made the original ovoposition. Our results enabled the corroboration of an ample range of responses in the infective capacity of this species, a characteristic that would normally be linked to the progenitors originating the hatch. Because this relationship prevents the establishment of a baseline for making comparisons among assays with gordiids, through the IIMA as a response parameter, we recommend expressing the IIMA values in each assay relative to their respective controls. These findings also provide evidence for the greater success in infections by certain members of the progeny over others. Finally, on the basis of the results obtained from this study, we stress the relevance of the use of the IIMA as a decisive aspect to be considered in different studies on the biology of Gordiida. Rev. Biol. Trop. 65 (1): 1-8. Epub 2017 March 01.Key words: parasite, Nematomorpha, infective capacity, infection index mean abundance, female.Within aquatic environments, the gordiids -freshwater representa...

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Modeling the geographical distributions of Chordodes formosanus and its mantis hosts in Taiwan, with considerations for their niche overlaps

Vivo

Huang

2022

Ecology and Evolution

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Species distribution models (SDMs) have conventionally been used for evaluating the distribution of individual species, but they can also be used, through comparing different SDMs, to evaluate the geographic similarity between taxa. In this study, we used a parasite and host system to infer the geographic overlaps between species with tight biological interaction, for example, parasites and their obligate host. Specifically, we used the horsehair worm Chordodes formosanus and its three mantis hosts to study the extent of niche overlap. We retrieved presence points for the host species and the parasite, and then we built SDMs with MaxEnt implemented in ENMeval using selected bioclim variables (based on variance inflation factor values) at 30s scale. The models showed that the hosts and parasite do not occur in the high elevation areas in Taiwan, which is expected based on their biology. Interestingly, the predicted parasite distribution included areas without collection records, implying local extinction or sampling bias. We subsequently evaluated niche overlap between hosts and the parasite according to five similarity indices (Schoener's D , I statistic, relative rank, Pearson correlation coefficient, and the rank correlation coefficient rho). Our models showed a high similarity of SDM predictions between hosts and the parasite. There were differences among metrics for which host shared the highest similarity with the parasite, but the majority of the results indicated that the Japanese boxing mantis had the highest niche similarity with the horsehair worm. The choice of the niche overlap metric to use can uncover information on the parasite's ecology, which can be important for endangered species. SDMs are reliable tools for host and parasite conservation management and could help improve our understanding of parasite biology and ecology.

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Phylum Nematomorpha

Cited by 31 publications

References 77 publications

Using Gordiid cysts to discover the hidden diversity, potential distribution, <br />and new species of Gordiids (Phylum Nematomorpha)

Using Gordiid cysts to discover the hidden diversity, potential distribution, <br />and new species of Gordiids (Phylum Nematomorpha)

Analysis of the Infectivity of Chordodes Nobilii Larvae (Gordiida, Nematomorpha)

Modeling the geographical distributions of Chordodes formosanus and its mantis hosts in Taiwan, with considerations for their niche overlaps

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