• Journal of fish pathology
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• v.17 no.1
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• pp.67-74
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• 2004

This study investigates the influence of waterborne ammonia and nitrite on the zoea and megalopa stage larvae of tiger crab, Orithyia sinica under laboratory condition, focusing on the effects on survival and growth as deleterious responses of toxicant. Survival rate of zoea stage larvae exposed to control levels, and to 5, 10, 20 and 50 mg/L total ammonia-N, using a continuous flow system for 20 days was 80, 77, 45, 40 and 37%, respectively. Growth rate of zoea stage larvae exposed to 20 and 50 mg/L total ammonia was significantly lower than in controls after 20 days (P< 0.05). Survival rate and growth rate of megalopa stage larvae exposed to ammonia also decreased at greater than 10 and 50 mg/L, respectively. In the nitrite exposure experiment with zoea and megalopa stage larvae of tiger crab, survival rate was decreased in a concentration and exposure period-dependent way. The growth rate of zoea and megalopa stage larvae of tiger crab exposed to nitrite decreased at greater than 150 mg/L nitrite concentration.