| Popis: |
Ammonium sulfate, (NH4)2SO4, is recommended for controlling the toxic alga Prymnesium parvum in fish production ponds. Because the un-ionized ammonia from ammonium sulfate that kills P. parvum is also toxic to fish, we determined the maximum concentration of un-ionized ammonia nitrogen that 4–5-d-old sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) can tolerate for 48 h; this was part of a study to assess the feasibility of using ammonium sulfate in sunshine bass fingerling production ponds. We compared sunshine bass treated with six ammonium sulfate treatments— 3, 5, 8, 10, 15, and 20 mg (NH4)2SO4/L at pH 8.5 and 20°C—with untreated fish (control). Fish mortality and total ammonia nitrogen were monitored for 48 h, and un-ionized ammonia nitrogen concentrations were calculated from the total ammonia nitrogen values. Mean mortalities for all treatments were 0.0–3.3% during the first 24 h and 8.0– 37.1% after 48 h. The mean 48-h cumulative mortality was 8.0% for th... |
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