# Diversity and distribution of helminth communities of the rodent Akodon montensis Thomas, 1913 (Rodentia: Cricetidae: Sigmodontinae) in preserved and altered environments in the Atlantic Forest, Brazil

## TL;DR

This study examines how habitat changes affect the helminth parasites of a rodent species in Brazil's Atlantic Forest.

## Contribution

It reveals that the rodent's parasite diversity remains stable across natural and altered environments due to its adaptability.

## Key findings

- Helminth diversity in the rodent did not significantly differ between preserved and altered habitats.
- Host characteristics and environment had little influence on parasite diversity within individual hosts.
- The rodent's ecological flexibility may lead to consistent parasite exposure across habitats.

## Abstract

The conversion of natural landscapes into agricultural and urban areas results in vegetation loss and habitat fragmentation, affecting biodiversity and favoring generalist species, such as Akodon montensis. This rodent species acts as a reservoir for zoonotic agents and harbors various parasites, including helminths, which are important indicators of environmental changes. The present study analyzed the structure, composition, and diversity of the helminth community of A. montensis in the Atlantic Forest, considering four locations in the state of São Paulo, Brazil. We calculated parasitological parameters (abundance, intensity and prevalence of infection) for each helminth species and evaluated helminth diversity within and between each individual host. In addition, we assessed the influence of type of environment (preserved forest or altered matrix) and host characteristics (sex and body size) on parasitological parameters of helminth species and on helminth diversity. A total of 64 individuals of A. montensis were analyzed, of which 60.9 % were infected with at least one helminth species. Nine species were collected, including eight nematodes and one cestode. No influence of the type of environment and host characteristics was observed on the parasitological parameters of some helminth species (e.g., Protospirura numidica criceticola, Rodentolepis akodontis, Stilestrongylus eta and Syphacia (Syphacia) carlitosi) and on the diversity of helminths within each individual host. A low effect of the type of environment on the diversity of parasites was observed among infracommunities. As an opportunistic species, A. montensis can exploit a wide range of resources and environmental conditions, making it less susceptible to variations in parasite diversity across habitats. These findings reinforce the importance of investigating parasite fauna in different landscapes to understand the impacts of anthropization on host-parasite interactions.

Image 1

•Helmint communities of Akodon montensis were analyzed in forest and altered habitats.•Local helminth diversity did not vary significantly between environments.•Environment had little effect on diversity among infracommunities.•Akodon montensis ecological plasticity may promote homogeneity in parasite exposure.

Helmint communities of Akodon montensis were analyzed in forest and altered habitats.

Local helminth diversity did not vary significantly between environments.

Environment had little effect on diversity among infracommunities.

Akodon montensis ecological plasticity may promote homogeneity in parasite exposure.