Avoidance Response of Young Rock Carp (Procypris rabaudi Tchang) to Gas Supersaturation as an Environmental Toxicity

Abstract-Avoidance response can be measured as starting for sublethal toxicity, and serve as a tool for environmental risk assessment and analysis of toxicological impact. In order to investigate behavioral alterations of young rock carp (Procypris rabaudi Tchang) induced by gas supersaturation, a two-choice laboratory apparatus and generated gas supersaturated water system was designed by our laboratory. With these laboratory systems, experiments were conducted to examine the avoidance behavior of rock carp exposed to gas supersaturation. Avoidance behavior was measured under different supersaturated water (105,115,125,135, &145%) and equilibrated water at 25°C water-temperature and 0.08 m waterlevel. The different avoidance percentage about the supersaturated water (105,115,125,135, &145%) were highly significant difference by a simple factor experiment of ANOVA. The avoidance percentage was bigger than 90% when gas supersaturation exceeded 135%, while the avoidance percentage was declining extremely with the gas supersaturation reducing. When gas supersaturation was below 115% the avoidance percentage was lower than 15%, and showed a preference for supersaturated water. Data from this experiment were presented to exemplify alterations in behavior of young rock carp under gas supersaturation conditions. The movement analyses can be used to identify characteristic behavioral responses to the supersaturated water, and assist in risk assessment the effects of high dams on aquatic ecosystem.