Abnormalities in amphibian populations inhabiting agroecosystems from Northeastern of Buenos Aires Province, Argentina

AGOSTINI M.G.; KACOLIRIS F.; DEMETRIO P.M.; NATALE G.S.; BONETTO C.; RONCO A.E.

DISEASES OF AQUATIC ORGANISMS

INTER-RESEARCH

Lugar: Oldendorf/Luhe; Año: 2013

0177-5103

The occurrence of abnormalities in amphibians has been reported in many populations, and its increase could be related to environmental pollution and habitat degradation. In this scenario, we evaluated the type and prevalence of abnormalities in five amphibian populations from agroecosystems with different degrees of agricultural disturbance (cultivated and reference areas). We detected nine types of abnormalities. The most frequent were those occurring in limbs. The observed prevalence of abnormality in assessed populations from cultivated and reference areas was the following: Rhinella fernandezae (37.1% and 10.2%), Leptodactylus latrans adults (28.1% and 9.2%) and juveniles (32.9% and 15.3%), and Hypsiboas pulchellus (11.6% and 2.8%). Scinax granulatus populations did not show abnormalities. Pseudis minuta, only detected in the reference area, exhibited a prevalence of 13.3%. Generalized linear mixed models showed significant differences (p < 0.05) in prevalence between cultivated and reference areas, for R. fernandezae, L. latrans and H. pulchellus being higher in cultivated areas. L. latrans juveniles were more vulnerable to abnormalities than adults (p < 0.05). The presence of abnormalities in some species inhabiting different agroecosystems suggests that environmental stress factors might be responsible for their occurrence. While we detected pesticides (endosulfan, cypermethrin, and chlorpyrifos) and lower dissolved oxygen levels in ponds of the cultivated area, no data is currently available on how other factors, such as injuries from predators and parasites infections, vary by land use. Further research will be necessary to evaluate possible causes of abnormalities detected in the present study mainly in the context of factor interactions.