INALI   02622
INSTITUTO NACIONAL DE LIMNOLOGIA
Unidad Ejecutora - UE
artículos
Título:
Chlorpyrifos and endosulfan effects on Palaemonetes argentinus (Crustacea: Palaemonidae): Oxygen consumption and ammonia excretion
Autor/es:
MONTAGNA, MARCELA C.
Revista:
Aquatic Toxicology
Editorial:
ELSEVIER
Referencias:
Lugar: California, USA; Año: 2008
ISSN:
0166-445X
Resumen:
Oxygen consumption and ammonia excretion rate were determined to evaluate the metabolic responses of the freshwater prawn Palaemonetes argentinus exposed to lethal and sublethal chlorpyrifos and endosulfan concentrations. A single prawn was placed in each respiratory chamber, where the dissolved oxygen was measured at intervals of one hour during the first four hours, and at 24 hr. Ammonia excretion was determined at the beginning and at 24 hr. During the first hours, the relationship between oxygen consumption and dissolved oxygen showed slopes significantly different in all the treatments regarding the control group. Moreover, the slope of interaction between energy expenditure and weight was different in 4.00 µg L-1 of chlorpyrifos. At 24 hr, the oxygen consumed was significantly high in prawns exposed to 12.00 µg L-1 of endosulfan. Mean ammonia excretion rate decreased as chlorpyrifos concentration increased, in contrast with the increment in said excretion due to endosulfan exposure. With the exception of 4.00 µg L-1 of chlorpyrifos, the O:N ratio of the treatments was lower than the control group, and these results indicated that prawns exposed to insecticides increased deamination associated with the use of proteins as a source of energy. Thus, these physiological parameters could be a sensitive tool to evaluate the metabolic alterations and a disruption of the energy balance associated with toxic exposure.