they breathe oxygen through gills, not air, can feel pain, possess complex sensory abilities, are social and cooperative, and some can even change their sex. 

Breathing Underwater:

Fish breathe oxygen, not air, using gills that filter oxygen from the water. 

Feeling Pain:

Scientific studies show that fish have pain receptors and react to pain, just like other animals. 

Sensory Abilities:

Fish have incredible sensory abilities, including the ability to detect vibrations in the water using their lateral line, and can even navigate using the Earth's magnetic fields. 

Social and Cooperative Behavior:

Many fish species are social and cooperative, forming complex social structures and working together for tasks like hunting or defense.