Which of the following is a common symptom of gas supersaturation in fish?

Gasping at the surface is a characteristic symptom of gas supersaturation in fish. Gas supersaturation occurs when water holds more dissolved gases than is typical, often due to rapid changes in temperature, pressure, or increased aeration. When fish are exposed to supersaturated conditions, the excess gas can lead to bubble formation in their tissues and bloodstream. Gasping at the surface is a behavioral response as they attempt to access water with lower gas concentrations to alleviate respiratory distress caused by these bubbles obstructing normal gas exchange.

In contrast, while excessive feeding, color change to bright red, and loss of appetite can indicate other health issues or stressors in fish, they are not widely recognized symptoms of gas supersaturation. Excessive feeding might suggest a normal feeding response or overfeeding, while a bright red color change usually reflects stress, inflammation, or certain diseases. Loss of appetite often pertains to other health problems and does not specifically relate to the physiological disruption caused by gas supersaturation.