EFFECT OF BASAGRAN HERBICIDE TOXICITY ON GROWTH PERFORMANCE, ACETYLCHOLINE CONTENT, AND ACETYLCHOLINESTERASE ACTIVITY IN NILE TILAPIA (OREOCHROMIS NILOTICUS)
Department of Fish Physiology and Spawning, Central Laboratory for Aquaculture Research, Agriculture Research Center, Ministry of Agriculture, Egypt.
Corresponding email: dr.[email protected]
|Received 5/ 1/ 2014||
Accepted 20/ 2/ 2014
The present study was conducted to evaluate the toxic effect of basagran herbicide on growth performance, acetylcholine (ACh) content, and acetylcholinesterase (AChE ) activity in Nile tilapia (Oreochromis niloticus). Fish (32.6± 1.22) were stocked at a rate of 15 fish/120-L aquarium and exposed to 0.0 (control), 20 (T1), 40 (T2), and 80 µL basagran/L (T3) for 3 months. Serum glucose and serum total protein as well as ACh content and AChE activity in different fish tissues were determined after 1, 15, 30, 60, and 90 days. The obtained results showed that fish growth decreased significantly with increasing the basagran concentrations. Also, significant increases in blood glucose and total protein levels were observed with increasing basagran concentrations. Furthermore, significant increases in ACh contents in the selected fish tissues were observed and their pattern was in the order: brain > gill > muscle > liver. On the other hand, AChE activities in fish gills, muscles, brains, and livers decreased significantly by increasing basagran concentrations suggesting the inhibitory effect of basagran herbicide on the AChE system. Inconsonance with the decrease in the AChE activities, there are corresponding increases in Ach contents of the different fish tissues suggesting a decrease in the cholinergic transmission and consequent accumulation of ACh in the same tissues; however this response is basagran dose-dependant.
Key word: Basagran herbicide, toxicity, acetylcholine, acetylcholinesterase, growth, Nile tilapia.