The fish may have escaped after being hit by a spear for several reasons:
1. Reflexes: When the fish is hit by the spear, it may have instinctively reacted and swam away to protect itself. Just like how we might flinch when someone tries to touch us unexpectedly, fish have reflexes that help them avoid potential danger.
2. Speed: Fish are known for their agility and speed in the water. After being hit by the spear, the fish may have used its strong muscles and fins to quickly swim away, outpacing the spear and escaping from its reach.
3. Injury: It's possible that the spear did not cause a fatal injury to the fish, allowing it to swim away. The fish might have been wounded or injured, but not severely enough to prevent it from escaping.
4. Camouflage: Some fish have evolved to blend in with their surroundings using camouflage techniques. After being hit by the spear, the fish might have utilized its natural ability to camouflage itself in the water, making it harder for the person to track and catch it.
5. Size and strength: Depending on the size and species of the fish, it may possess a powerful body and strong muscles, enabling it to break free from the spear and escape. The force of the impact might not have been enough to hold the fish in place, allowing it to swim away.
In summary, the fish could have escaped after being hit by a spear due to its reflexes, speed, lack of a fatal injury, camouflage abilities, or its size and strength.