Effect of altitude and spatial heterogeneity on the host-parasite relationship in anurans from a remnant humid forest in the brazilian semiarid.

In the present study, we investigated the effect of habitat heterogeneity, elevation gradient, and phylogenetic distance of host species on the abundance and richness of anuran endoparasites, assuming that parasites follow the distribution of their hosts independently of environmental variation. We collected 192 anurans distributed in three altitude ranges: 100-200 m, 400-500 m, and 700-800 m. We performed discriminant principal component analysis to analyze the interrelationships between environmental heterogeneity and the distribution of parasite and host species in the formation of species groups in each altitude range. We estimated the niche width and parasite overlap, using host species as a variable, and assessed whether parasite abundance is more influenced by historical (distance host phylogeny) or ecological effects in each altitude category and overall. Finally, we use network analyses to understand how interactions between parasites and hosts are formed along the altitude gradient. We found 22 parasite species, and the overall prevalence of infection was 74%. In our study, we did not identify environmental (altitude gradients and heterogeneity) or phylogenetic effects acting on the parasite species diversity. Overall, our results suggest that the parasites are distributed following the dispersal of their hosts and are dispersed among most anuran species.

Endoparasites of Adelophryne maranguapensis Hoogmoed, Borges & Cascon, 1994 (Anura, Eleutherodactylidae), an endemic and threatened species from an altitude swamp in northeastern Brazil.

Adelophryne maranguapensis is an endangered anuran species endemic to the Maranguape residual mountain, Ceará State, northeaster Brazil, which is under strong anthropogenic pressure. There are still few studies on the natural history of this species that allow a better understanding of its biology and can provide the basis for conservation actions. Studies on endoparasitism are an important source for the comprehension of ecological relationships, as well as for providing information on host biology and its relevance to ecosystems. Thus, we present information about the endoparasites helminths, the relationship of parasite abundance with the size of individuals and the parasite difference between the sexes in A. maranguapensis, to elucidate some characteristics in the host-parasite relationship and the use of the area of this anuran. We analysed 107 specimens deposited in the Herpetological Collection of the Federal University of Ceará, sampled from 2010 to 2012. Total prevalence of 24.30% was recorded, and four parasitic taxa were identified, Aplectana sp., Physaloptera sp., Parapharyngodon sp. and an unidentified Ascarid. No relationship between the abundance of parasites and snout-vent length was found and the parasite difference between the sexes. Even though identification of the parasites at species level was not possible, A. maranguapensis follows a common pattern in parasitism of Neotropical species.

Helminths Associated with Three Physalaemus Species (Anura: Leptodactylidae) from Caatinga Biome, Brazil.

OBJECTIVES AND DESIGN: Knowledge of which and how many species are part of an ecosystem is fundamental to understanding the diversity of organisms, including parasitic organisms that vary widely among host populations. This study describes the composition, infection patterns, and similarity in composition of helminths associated with P. albifrons, P. cicada, and P. cuvieri. MATERIALS AND METHODS: Four samplings were carried out in two caatinga areas in the southern region of Ceará State, Brazil. The specimens were collected by active search, necropsied, and surveyed for helminths. The infection patterns for all helminth species found were estimated through prevalence, mean abundance, and mean intensity of infection. RESULTS: A total of 242 helminth specimens were collected from 264 hosts-100 Physalaemus albifrons with overall prevalence of 20%, 93 Physalaemus cicada with overall prevalence of 27%, and 71 Physalaemus cuvieri with overall prevalence of 15%. Ten parasite taxa with a mean of one-three parasite species per host were identified. The nematode Raillietnema spectans was present in the three host species and had the highest prevalence. CONCLUSIONS: The results of this study represent 38.4% of known parasites for the species of the subfamily Leiuperinae, and 52.6% for the species of Physalaemus. Four parasite taxa (Oswaldocruzia cf. mazzai, Raillietnema spectans, Schrankiana schranki, and Cylindrotaenia americana) are new records for the host species studied, contributing to the knowledge of the parasitic interactions of amphibians of the genus Physalaemus.