Seasonal variation of Hedruris dratini (Nematoda) parasitizing Hydromedusa tectifera (Chelidae), with focus on host\u2019s torpor state

Julia Inés Diaz,Ezequiel Palumbo,Leandro Alcalde,María Julia Cassano

doi:10.1186/s40850-021-00078-6

Julia Inés Diaz, Ezequiel Palumbo + Show 2 more

Open Access

https://doi.org/10.1186/s40850-021-00078-6

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Abstract

BackgroundThe aim of this study was to analyze the seasonal distribution of the nematode Hedruris dratini parasitizing the South American Snake-necked turtle Hydromedusa tectifera and the amphipod Hyalella spp. in an urban stream. We focused on understand which strategies parasite population displays to get through the host’s hibernation period.ResultsThe highest prevalence and abundance of H. dratini were found in summer. The parasitic load was lower in winter, however there were no significant differences when it was compared with autumn and spring. Generalized linear model identified the temperature as a determining factor for the presence of parasites in turtles.ConclusionsOur results indicate that, beside turtles enter in a diapause state, the life cycle of H. dratini never stop throughout the year, being a continuous transmission between both the intermediate and final host throughout the year. Turtles feed and become infected with parasite larvae even in winter although with a lower ingestion rate.

Highlights

Which factors influence the success of a parasite population? Many studies have analyzed the population dynamic of parasites in diverse kinds of host and environmental systems (e.g. [3, 4, 13, 38])
The stream originates in semirural areas at the NW of the city and its middle course runs through urban areas before turning again into a rural stream that ends in the Río de La Plata Estuary by a channelized upper portion
Ten turtles belonged to SC I (< 130 mm), 96 to SC II (130–200 mm), and 54 to SC III (> 200 mm)

Summary

Introduction

Which factors influence the success of a parasite population? Many studies have analyzed the population dynamic of parasites in diverse kinds of host and environmental systems (e.g. [3, 4, 13, 38]). Only few of them have dealt with this relationship from hosts that enter in a deep pause during cold months (hibernation) This last point was mostly analyzed for mammals [10, 19, 29, 31, 32, 35]), and reptiles from North Hemisphere in a lower degree [16, 18, 40] How does this behavior influence the population dynamic of a parasite species if the. When environmental temperature decreases freshwater turtles tend to find refuge, stop feeding and diminish their metabolic rate to a minimum, entering into dormancy (torpor) This state affects nutrition, immunity, habits and dispersion, and it may last days, weeks or several months depending on the severity of climatic features [39]. We focused on understand which strategies parasite population displays to get through the host’s hibernation period

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