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Hormonal and
haematological responses of Clarias gariepinus (Burchell
1822) to ammonia toxicity
F. Ajani
Department
of Animal Science and Fisheries Management, Bowen
University, Iwo, Osun State, Nigeria. E-mail:
funmilolajani@yahoo.com.
Accepted
8 July, 2008 |
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This study assessed hormonal and haematological responses of
Clarias gariepinus to ammonia toxicity. Laboratory
study of haematological responses of adult C. gariepinus
to sub-lethal level of ammonia (2.2 g/l) at different
exposure hours (0, 6, 24, 48, 72, 96 h) were carried out.
Blood samples of C. gariepinus were collected at each
exposure hour and evaluated for primary and secondary stress
indicators. Data obtained were subjected to simple
descriptive analysis and analysis of variance. Plasma
cortisol level of C. gariepinus increased
significantly (P < 0.05) from 0 h (01.0 ± 0.1 ng/dl) to 48 h
(154.0 ± 1.0 ng/dl) after which it decreased and stabilized
at 72 h (106.0 ± 1.1 ng/dl). Packed cell volume (PCV) and
Red blood cell (RBC) were elevated after 6 h of exposure and
decreased significantly (P < 0.05) at 48, 72 and 96 h of
exposure in fish exposed to sub-lethal level of ammonia. The
mean plasma glucose level recorded at 0 h (95.00 ± 1.00 mM)
decreased significantly (P < 0.05) with the lowest mean
value of 37.00 ± 1.05 mM obtained at 96 h of exposure.
Haematological and hormonal balances of adult C.
gariepinus were affected under short-term exposure to
ammonia toxicity.
Key
words:
Hormonal, Haematology, Clarias gariepinus, ammonia,
toxicity. |
