College of Fisheries, Dr Balasaheb Sawant Konkan Krishi Vidyapeeth, Ratnagiri-415 629, Maharashtra, India
*Corresponding Author: F. Sanudi, College of Fisheries, Dr Balasaheb Sawant Konkan Krishi Vidyapeeth, Ratnagiri-415 629, Maharashtra, India, Email: fsanudi@gmail.com
Online published on 15 May, 2021.
Sub-lethal toxicity bioassay experiments were conducted to determine the toxicity of glyphosate herbicide on Koi carp, Cyprinus carpio fingerlings. Koi carp fingerlings with mean length 8.06 ± 0.99 cm were obtained from a freshwater fish seed hatchery of the university.
The fishes were exposed to sub-lethal concentrations i.e. 1/10th (3.6 mgL-1) and 1/5th (6.6 mgL-1) of glyphosate. Oxygen consumption rate, Ammonia-Nitrogen excretion rate, Oxygen: Nitrogen ratio and food consumption rate were recorded after every 7 days for a period of 28 days.
Results indicated significant decrease (P<0.05) in oxygen consumption in 1/10th and 1/5th of LC50 concentrations. Ammonia- Nitrogen significcantly increased in exposed fishes. Oxygen : Nitrogen ratio and food consumption rate also significantly decreased (P>0.05) in treated fishes. The results indicated that glyphosate had impacts on exposed fish, hence, the need of regulation of its usage to protect non-targeted species and the environment.
Bioassay, Cyprinus carpio, Glyphosate, Herbicide, Koi carp, Lethal toxicity
