The influence of habitat fragmentation on helminth communities in rodent populations from a Brazilian Mountain Atlantic Forest

Abstract

AbstractThe influence of habitat structure on helminth communities of three sigomdontinae rodent species (Akodon cursor, A. montensisandOligoryzomys nigripes) was investigated in forest fragments within an agricultural landscape in south-eastern Brazil. This is a pionner study correlating the occurrence of helminth species of rodent hosts with microhabitat characteristics. Rodents were collected from 12 fragments and in a continuous conserved area. Up to 13 nematode, three cestode and two trematode species were identified, and habitat fragmentation was found to have more influence on the helminth composition ofO. nigripescompared to the other two rodent species. Fragmentation appeared to limit the development of some helminths’ life cycles, e.g. with some species such asTrichofreitasia lenti, Protospirura numidica, Cysticercus fasciolarisandAvellariasp., occurring mostly in areas with less anthropic impact. However, fragmentation did not seem to affect the life cycles of other dominant helminths, such as the trematodeCanaania obesa,the nematodesStilestrongylus lanfrediae,S. etaandS. aculeata,and the cestodeRodentolepis akodontis.The helminth community structure followed a nested pattern of distribution inA. montensisandO. nigripes.Stilestrongylus lanfrediaeseemed to be more associated with dense understorey,C. obesawith open canopy and dense understorey, andGuerrerostrongylus zettawith organic matter on the ground. Their presence in each area may be explained by aspects of their life cycles that take place in the external environment outside the host.