Assisted phoresy of invertebrates by anurans in tank bromeliads: interspecific relationship

Phytotelmata are habitats that house several species. Oftentimes invertebrate species need to disperse themselves sometimes carried by other animals, an interaction called phoresy. Phoresy can be influenced by different factors, therefore, we aim to investigate which factors influence the phoretic potential between anurans and invertebrates from bromeliads in semideciduous Atlantic Forest, as well as whether there is specificity of invertebrates with any anuran species. We tested if (a) phoresy is more common under conditions with higher rainfall; (b) there are some species of anurans that influence the phoresy of invertebrates more than others; (c) size is an important factor to phoresy. The study was developed during six campaigns in two sites containing the bromeliad Aechmea leptantha. In each campaign, water of bromeliads was collected and all anurans found in bromeliads were processed by washing the skin to collect adhered invertebrates. We recorded the prevalence, average intensity and average abundance of invertebrates between anuran species. We verified the similarity of invertebrates between anuran taxa and we tested the hypothesis of independence between them. In order to identify which factors affect phoresy, we performed a GAMLSS analysis. Invertebrates were present on 54.4% of anurans distributed in five species: Dendropsophus decipiens, Scinax pachycrus, S. x-signatus, S. auratus and Pristimantis ramagii. The estimated densities for prevalence, average intensity and average abundance of invertebrates showed distinct shapes among the anuran species, of which not all participate in the same way in invertebrate transport. The mean phoretic potential showed a significant relationship with anuran length and rainfall.