Nematodes of Amphibians from the South American Chaco: Distribution, Host Specificity and Ecological Aspects

GONZÁLEZ, CYNTHYA E.; HAMANN, MONIKA I.; DURÉ, MARTA I.

Diversity

MDPI.

Lugar: Basel; Año: 2021 vol. 13

Thisis the first review of the nematode parasites of amphibians from Dry Chaco (DC)andHumid Chaco (HC) ecoregions of South America, covering aspects related to theirsystematics,distribution,host range and ecology, including their life cycles. Of approximately 100speciesofamphibians that inhabit these ecoregions, the nematode parasites of 32 speciesare known. Theparasitespecies consisted of 51 taxa: 27 in HC and 18 in DC. The family Cosmocercidaealone included18species. Aplectana hylambatis andCosmocerca podicipinus showedthe widest geographical and hostdistribution.Leptodactylus bufonius and Rhinellamajor presented a high number of nematodeparasites.Thespecies richness of nematodes was related to the host body sizes and to thestrategy to obtain prey.Themean species richness was higher in terrestrial amphibians with intermediatecharacteristics in thegeneralist?specialistspectrum in terms of diet, and in amphibians with intermediate characteristicsbetweenactively foraging and the ?sit-and-wait? approach in terms of searching forprey. The patternsofsimilarity among amphibian species showed groups linking with their habitats.Nematodes usuallyhavedirect life cycles with the infectious form entering the host passively oractively. However, manyamphibians are alsoinvolved in heteroxenous cycles that develop in the aquatic environment.