Corticosterone response in Broad-snouted caiman (Caiman latirostris) after restraint conditions

PARACHÚ MARCÓ, MARÍA VIRGINIA; PABLO ARIEL SIROSKI; GRACIELA ALMA JAHN; CARLOS IGNACIO PIÑA

Lake Charles

Congreso; 23th Reunión mundial del Grupo de Especialistas en Cocodrilos (CSG/SSC/UICN); 2014

CSG - McNeese State University

Corticosterone (CORT), the main stress hormone in reptiles, allows their physiology and behaviour helps the organism to deal with acute or chronic stressors. In this study we investigated changes in plasma CORT in juvenile Broad-snouted caimans (Caiman latirostris) in response to acute stress. Ten juvenile caimans hatched from artificially incubated eggs and raised under controlled conditions were held in plastic trays to produce restraint conditions inducing stress. Half of animals were maintained at room temperature (20 ± 1.2°C) and the remained animals at environmental temperature (12.7 ± 1.5°C). An initial blood sample was taken and further samples collected at 0.15, 0.30, 1, 2, 4, 8 and 12 hours. CORT was measured in plasma by radioimmunoassay (RIA). Differences among animals were observed in plasma CORT. Plasma CORT in juvenile caimans bled immediately at starting time ranged between 0.06 and 6.85 ng/mL. There was a tendency for CORT levels to increase progressively after the initial blood samples until 8 hours in animals at room temperature. However, further changes in CORT concentration in animals maintained at environmental temperature rose progressively until 12 hours. Our results lend support that handling Broad-snouted caiman, taking multiple blood samples, and keeping them restrained is a severe acute stress to the animals. In addition, we also observed that temperature could produce early adrenocortical axis activation in Broad-snouted caiman.