Helminth community in the Llanos frog, Lepidobatrachus llanensis (Ceratophryidae), from the Dry Chaco

DURÉ, M.I.; GONZALEZ, C.E.; HAMANN, M. I.; PALOMAS, Y. S.

South American Journal of Herpetology

Brazilian Society of Herpetology

Año: 2022 vol. 25 p. 1 - 6

1808-9798

Abstract. The presentstudy predicts that helminth community diversity and parasite transmission areinfluenced by host behavior and its habitat. This prediction was tested byanalyzing for the first time the helminth community of Lepidobatrachus llanensis, an aquatic species that inhabits exclusively ephemeral water bodies inthe Dry Chaco ecoregion. In the drought periods, L. llanensis burrows underground and forms a cocoon to minimize wáter loss,emerging again in the rainy season (e.g., in summer months). A total of 21frogs was examined for parasites. Parasite community structure was analyzedusing helminth parasite richness, diversity, and abundance. The helminthcommunity of this frog consisted of 17 species, composed mostly of platyhelminthspecies (76%), followed by nematodes (24%). Ophiotaeniasp. was mostprevalent (71%, confidence interval [CI]: 51.4?90.6%), followed by Choledocystus elegans (57%, CI: 35.8?78.2%). Infected frogs harbored a maximum of sevenhelminth species. At the infracommunity level, the mean species richness was 4.24 ± 1.79 per infected frog. Parasites werefound in all major organs, with highest prevalence in the digestive tract.Helminth species showed a typical aggregated pattern of distribution with unequalabundances. Parasite transmission to the frog host occurs by oral ingestion andskin penetration. As predicted, we found that the composition of the parasitecommunity of this aquatic frog included multiple helminths, including parasiticspecies characteristic of both aquatic and terrestrial life cycles, withgreater occurrence of trematodes that likely benefit from seasonal hostaggregation during the rainy period associated with their reproductivestrategies and by environmental factors such as seasonal dwelling in dry soil.This behavior in an otherwise aquatic frog enables infections by nematodes (L₃)with a terrestrial life cycle absent from other aquatic frogs from SouthAmerica.