Behavioral responses of Odontophrynus americanus tadpoles (Anura: Leptodactylidae) to fish chemical cues

SCARABOTTI, PABLO AUGUSTO; LÓPEZ, JAVIER ALEJANDRO; GHIRARDI, ROMINA

CUADERNOS DE HERPETOLOGíA

Asociación Herpetológica Argentina

Año: 2007 vol. 21 p. 45 - 52

0326-551X

Abstract. — Many amphibian larvae live in turbid and vegetated habitats with very limited visibility. In these habitats, the use of chemical cues for predator detection may be more reliable than visual ones. Odontophrynus americanus tadpoles inhabit floodplain ponds of the middle Paraná River, Argentina, where they frequently encounter low visibility conditions. We hypothesize that tadpoles of this species can detect predators and subsequently respond with antipredator behaviour by means of chemical cues from predators. In the present work, we ran three separate laboratory experiments to evaluate whether O. americanus tadpoles respond behaviourally to a chemical stimulus of the characid fish Astyanax fasciatus.  We evaluated behavioural responses by observing changes in activity level, refuge use and spatial distribution of the tadpoles. In the presence of the fish chemical stimulus, tadpoles reduced their activity by 27 % and increased refuge use approximately five-fold, but they did not exhibit spatial avoidance from the predator stimulus. The behavioural responses of the tadpoles of this species may reduce the rate of encounter and attack by predators.