Evaluation of the toxicity of ammonia polluted waters for Carassius auratus gibelio (Bloch, 1782) by the «time sampling» method

Purpose. To determine the possibility of performing an express-evaluation of the toxicity of ammonia polluted waters based on ethological parameters of Carassius auratus gibelio (Bloch,1782) with the use «time sampling» method. Methodology. For biotesting in August 2017, water samples were taken from the Denishevsky reservoir of the Teteriv river and water supply network of the water service company, which were placed in aquaria (10 dm3) and a control and experimental groups of fish were formed according to the following scheme: control group – samples of settled (24 hours) clean tap water; experimental group D-1 – water samples from the Denishivsky reservoir with the total ammonia concentration of 1.5 mg/dm3; experimental group D-2 – samples of settled (24 hours) tap water with the total ammonia concentration of 1.5 mg/dm3. Test-objects were females of C. auratus gibelio, in which the parameters of typical and non-typical motor activity and feeding behavior were determined. Fish were exposed for 12 hours. For both experimental groups, water toxicity indexes were calculated in comparison with the control. Findings. In the studies, we showed the possibility of using the «time sampling» method for rapid assessment of the toxicity of polluted waters with ammonium concentration of 1.5 mg/dm3 based the ethological parameters of Prussian carp (C. auratus gibelio), which included the instantaneous fixation of the number of individuals preferring one or another act of behavior. It was shown that C. auratus gibelio females reacted on ammonia content by impairing the motor and feeding behavior. Settled tap water artificially pollution with ammonia (group D-2) appeared to be more toxic for fish than water polluted by natural way. Immobilization of individual fish in the group D-1 was 6.60% lower, while their survival rate was 11.11% hogher compared to the group D-1. Unlike fish of the experience groups, fish in the control group exhibited only single untypical ethological acts. The calculation based on the behavioral parameters of Prussian carp females demonstrated mainly medium (group D-1) and high (group D-2) levels of acute toxicity of experimental waters. Originality. For the first time, the express-evaluation of the toxicity of water with elevated ammonium content (1.5 mg/dm3) was carried out by observing the motor activity and feeding behavior of Prussian carp (C. auratus gibelio) by the «time sampling» method. Practical use. The results of the study are used for the rapid assessment of the toxicity of water of surface water sources of the Teteriv river.