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Acute toxicity of ammonia to the early stage‐larvae and juveniles of Eriocheir sinensis H. Milne‐Edwards, 1853 (Decapoda: Grapsidae) reared in the laboratory
Author(s) -
Zhao JH,
Lam T J,
Guo JY
Publication year - 1997
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1046/j.1365-2109.1997.00888.x
Subject(s) - biology , eriocheir , acute toxicity , ammonia , decapoda , zoology , bioassay , juvenile , larva , toxicology , toxicity , fishery , crustacean , ecology , chemistry , biochemistry , organic chemistry
Static‐renewal bioassays were performed to evaluate the acute toxicity of ammonia to Eriocheir sinensis (H. Milne‐Edwards) at three growing stages, namely zoea‐I, zoea‐II, and juvenile (0.06 g wet weight per crab). The 24 h LC 50 values were 13.3, 20.2, and 109.3 mg (NH 3 + NH 4 + ) 1 −1 (0.47, 0.71, and 3.10 mg NH 3 I −1 ), the 48 h LC 50 values being 6.8, 10.3, and 60.9 mg (NH 3 + NH 4 + ) 1 −1 (0.24, 0.36, and 1.73 mg NH 3 1 −1 ), while the 72 h LC 50 values were 5.7, 7.6, and 45.3 mg (NH 3 + NH 4 + ) 1 −1 (0.20, 0.27, and 1.29 mg NH 3 1 −1 ) for zoea‐I, zoea‐II, and juveniles, respectively. The 96 h LC 50 value for juveniles was 31.6 mg (NH 3 + NH 4 + ) 1 −1 (0.90 mg NH 3 1 −1 ). It was evident that the tolerance to ammonia increased during the same exposure time as the larvae developed to juveniles and decreased with prolonged exposure time. Compared with larvae, juveniles were more sensitive to the fluctuation of ambient ammonia concentrations in the certain range within which partial kills took place. The ‘safe level’ of ammonia based on the 96 h LC 50 value and an application factor of 0.1 was 3.16 mg (NH 3 +NH 4 + )1 −1 (0.09 mg NH 3 1 −1 ) for juveniles and those for zoea‐I and zoea‐II were 0.57 and 0.76 mg (NH 3 + NH 4 + ) 1 −1 (0.02 and 0.03 mg NH 3 1 −1 ) based on 72 h LC 50 values.