Batrachochytrium dendrobatidis in Argentina: First record of infection in Hypsiboas cordobae and Odontophrynus occidentalis tadpoles, in San Luis province, Argentina

Abstract

On October 12th 2009, ten live larvae of Hypsiboas cordobae and Odontophrynus occidentalis were collected randomly in a pond during a field survey in the Strict Natural Reserve “Quebarada de las Higueritas” , San Luis province.The individuals were fixed in the field in 10% neutral buffered formaldehyde and then transferred to ethanol 70%. All oral structures of tadpoles were examined visually in the laboratory under a stereoscopic microscope. Samples of the queratinazed mouthparts were taken, which were dehydrated, paraffin-embedded and cut into five micron–thick sections for histological analysis. We identified anomalies in the keratinized mouthparts 5 of 10 individuals analyzed. The anomalies included mainly lack of pigmentation in upper and lower jaw sheaths, erosion of their cutting edge and absence of serrations, and some time lost of some labial teeth (Fig. 2). For histological analysis 7 of the 10 larvae analyzed were positive to Bd presence. Spherical and ovoid zoosporangia, empty or containing zoospores, were identified in the keratinized mouthparts. The sporangia ranged between 5 and 12 µm in diameter.