Atividades de cultivo e seus efeitos em comunidades de helmintos de quatro populações de anuros (Anura: Leptodactylidae) do nordeste brasileiro

Abstract

In recent decades, amphibians around the world have been suffering a sharp population decline, and several studies are being made to understand the main causes of this. Farming activities is one of the human actions that affect the environmental dynamics of areas where amphibians are found. Areas where these activities occur become very affected environments, because they are usually exposed to a variety of chemicals, such as pesticides and agrochemicals, and can directly or indirectly affect the life cycle of amphibians. Ecological relationships between parasite and host are important factors to consider when studying the health of amphibians, as they are a heavily parasitized group. These relationships are strongly influenced by the habits of the host, the habitat it lives in, and all the variables that affect environmental conditions. Anurans of the Leptodactylidae family, being very diverse, well distributed and abundant in South America, are excellent models for ecological studies on parasitism. Thus, the present study aimed to relate the possible effects that areas with farming activities exert on the ecosystem, affecting patterns in the parasite load of four populations of Leptodactylus macrosternum. The study was carried out in the Ceará municipality of Tabuleiro do Norte, near the Jaguaribe River. A total of 54 hosts from four different areas (two areas with commercial farming activity and two without) were analyzed for parasite load. There were no major variations in parasite richness between hosts in each area. However, some species were more abundant in certain areas. Environments anthropized by farming activities may cause changes in parasite load, and several factors are involved in infection patterns. Just as some parasite species may be negatively affected by agricultural products, others may be indirectly favored by them, showing a complex relationship between environmental conditions and parasite infection patterns. Thus, further studies will be done to better understand the effects of farming areas on parasite infection patterns in anurans.