Lead’s effects on oxygen consumption and ammonia excretion in the pink shrimp (Farfantepeneaus paulensis) in relation to salinity

DOI: 10.15343/0104-7809.2012364594601

Abstract

The objective of this study was to provide information on the toxicity of lead to the pink shrimp (Farfantepeneaus paulensis)
based on oxygen consumption and the excretion of ammonia at different salinity levels. Organisms were collected and
analyzed in the Cananeia region, São Paulo, Brazil. The study of lead toxicity is very relevant for the history of the region,
due to the high economic value of shrimps and the estimated future environmental impacts. 45 organisms were collected
and acclimated with constant aeration. Five replicates were used for routine measurement of metabolism in salinities 10,
20 and 30 and temperature of 27 °C. Four different lead concentrations were tested: 0.04, 0.4, 0.08 and 2.12 mg/L, beyond
control. Respirometers chambers were used for 60 minutes. Dissolved oxygen was determined by the method of Winkler
and ammonia based on phenol spectrophotometric method. The average oxygen consumption and ammonia excretion
were evaluated using analysis of variance (p <0.05). Results showed a predominant decrease in rates of ammonia excretion
and oxygen consumption. This fact allows us to infer that there was a shift in the metabolic pattern of the organisms as
regards detoxification and stabilization of metabolic patterns. Analysis of variance showed that oxygen consumption and
ammonia excretion average lead concentrations of 0.8 and 2.12 mg/L were significantly different as compared to controls.