Evidence of phoresy by leeches (Hirudinoidea) on <em>Rhinella abei</em> (Anura: Bufonidae) in the Atlantic Rainforest in the state of Santa Catarina, southern Brazil

Abstract

In the Atlantic Rainforest of the Parque Estadual da Serra do Tabuleiro, state of Santa Catarina, southern Brazil, we found Rhinella abei (Bufonidae) infested by leeches (Hirudinoidea). We captured 27 toads on the margin of a lagoon both inside and outside water in a survey carried out during one night, and 13 of which had a total of 30 leeches (mean intensity of infestation = 2.3 ± 1.3). We did not observe wounds, scars and/or hemorrhages caused by the leeches on the toads examined, no hemorrhaging after the removal of the leeches, and the leeches removed from the toads were empty of blood. This evidence led us to theorize that the leeches were not parasitizing the toads but had a phoretic relationship. The leeches were found on both dorsal and ventral surfaces (13 on each) of the toads and were predominantly on the toads’ axils followed by back and thighs. The average snout-vent length of the toads was 69.2 ± 5.3 mm and their average body mass was 27.1 ± 6.9 g. The number of leeches found on a toad was not related to its snout-vent length or body mass. We are unaware of any previous records of leeches using anurans as dispersal agents, as suggested in the present study.