1. The toxicity of ammonia to Macrobrachium larvae was tested at pH 6.83, 7.60, and 8.34, and the respective 144 hr LC50 values were 80, 44, and 14 mg ammonia/liter. 2. Toxicity of ammonia was not due solely to the NH3 molecule. In solutions of different pH and equal NH3 concentrations, survival was greatly reduced as NH4+ levels increased. 3. A model is proposed to explain the differential effect of ammonia as pH varies. At higher pH (8.4) toxicity results from copious diffusion of NH3 into larvae. At lower pH (6.8) toxicity is thought to result from competitive inhibition of Na+ transport by NH4+. 4. Retardation of growth was documented in sublethal concentrations of ammonia at 6.8 and 7.6. The average dry weight was about 26% less than that of controls (P < 0.05) after a seven day exposure. 5. Results are discussed relevant to the culture and maintenance of crustaceans, and it is concluded that ammonia will not pose a substantial threat in adequately managed systems.
INTERACTION OF IONIZED AND UN-IONIZED AMMONIA ON SHORT-TERM SURVIVAL AND GROWTH OF PRAWN LARVAE, MACROBRACHIUM ROSENBERGH.
D. Armstrong,Deborah J. Chippendale,A. Knight,J. Colt
Published 1978 in The Biological Bulletin
ABSTRACT
PUBLICATION RECORD
- Publication year
1978
- Venue
The Biological Bulletin
- Publication date
1978-02-01
- Fields of study
Biology, Medicine, Environmental Science
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
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