Fish have many adaptations for aquatic life, such as gills and swim bladders. Fish reproduce sexually and often participate in spawning, where a group of fish releases gametes at the same time to increase the chance of fertilization. There are five classes of fish, and each class has adapted differently for survival in their respective habitats.
Fish: Vertebrate that lives in water and has gills for absorbing oxygen
Swim Bladder: Gas-filled internal organ that allows fish to move up and down in the water.
Spawning: A group of fish all release their gametes at the same time.
Endoskeleton: Internal skeleton that provides support and protection.
Cartilage: Tough tissue containing a protein called collagen.
Bone: Hard tissue containing a collagen matrix filled with minerals like calcium.
Fish have several adaptations for water:
Fish are divided into 5 classes: