1. Breathing: Fish breathe dissolved oxygen from the water through their gills. When a fish is out of the water, it can no longer breathe and begins to suffocate. This causes them to flop around in an attempt to get back into the water.
2. Maintaining balance: Fish use their fins to maintain balance and orientation in the water. When they are out of the water, they lose their ability to control their movements and may flop around as they try to regain their equilibrium.
3. Escaping predators: Some fish may flop around as a defensive mechanism to escape from predators. By creating sudden and erratic movements, they can confuse predators and make it more difficult for them to catch them.
4. Spasm response: In some cases, fish may flop around due to a spasm response triggered by stress or injury. This can happen when they are handled improperly, exposed to extreme temperatures, or experience other environmental stressors.
It's important to note that fish are not adapted to survive out of the water for extended periods. Prolonged exposure to air can cause severe stress, injury, and ultimately death. Therefore, it's crucial to handle fish carefully and return them to the water as soon as possible to ensure their well-being.