It uses there fin to move and there gills to breath in oxygen
They swim using there flipper things!!
They swim and are popular in salt water aquariums.
swim bladder
to move up and down in water
to move up and down in water
Fish can swim because they have streamlined bodies that reduce water resistance, paired fins that provide stability and maneuverability, and a swim bladder that helps with buoyancy control. These adaptations allow fish to move efficiently through water.
They swim
They swim
they swim
They swim.
To control general attitude/level in the water, fish have a "swim bladder" in order to move they have muscles and fins.
Fish swim in order to move from place to place for whatever reason they choose.