Acute toxicity of nitrite to tiger prawn, Penaeus monodon, larvae

Abstract

Larval prawn Penaeus monodon exhibited a progressive increase in nitrite tolerance as the larva metamorphosed from nauplius to the postlarva stage. The 24-h LC50 nitrite effects on nauplii, zoea, mysis and postlarvae were 5.00 mg/l, 13.20 mg/l, 20.65 mg/l and 61.87 mg/l NO2N, respectively. The 48-h LC50 values on mysis and postlarva were 8.30 mg/l and 33.17 mg/l NO2N while the 72-h and 96-h LC50 values on postlarva were 20.53 mg/l and 13.55 mg/l NO2N, respectively. A “safe level” of nitrite was estimated at 1.36 mg/l NO2N on the basis of 96-h LC50 for postlarvae while a more conservative estimate of a “safe level” is 0.11 mg/l NO2N based on an estimated 96-h LC50 for nauplii.