Evaluation of stress responses to water molds in embryos of Physalaemus albonotatus (Anura: Leptodactylidae)

GHIRARDI R.; CAZENAVE J.; LOPEZ J.; ANTONIAZZI C. E.; PEROTTI M. G.

Herpetological Conservation and Biology

Herpetological Conservation and Biology

Lugar: Fresno CA; Año: 2018 vol. 13 p. 216 - 223

1931-7603

Infections by water molds of the genus Saprolegnia (Oomycetes) have been associated with deaths of egg masses in different anuran species; however, how water molds induce physiological responses in early and susceptible developmental stages of anurans is poorly known. To assess whether or not embryos of Physalaemus albonotatus (immobile and susceptible life stages) respond to Oomycetes infection, we performed a 4 d experiment exposing early stage embryos to the water mold Saprolegnia-like sp. We assessed mortality, hatching time, and oxidative stress (antioxidant enzyme activities and lipid peroxidation levels). Presence of water molds in infected embryos was not evident to the naked eye until 1 to 1.5 d after inoculation. Mortality was significantly higher in the water mold treatment than in the control treatment. Embryos exposed to Saprolegnia-like sp. hatched 24 h earlier than those in control treatment. Among enzymatic activities, only catalase enzyme showed a significant depletion in embryos exposed to water molds compared to control groups. These results emphasize the need to explore oxidative stress markers along with embryonic development at key stages, focusing on those early stages where hatching is induced by water molds infection