Seahorses breathe with gills and use a swim bladder to control their buoyancy. They are classified as "bony fish," along with tuna and cod. While they have no tail fins (like other fish that are better swimmers), they have four other fins that they use to get around - one at the base of the tail, one under the belly, and one behind each cheek. Seahorses are not, however, very good swimmers.
As barely mediocre swimmers, seahorses prefer to stay stationary (or as stationary as possible in the ocean's motion). They tread water by beating their tiny fins rapidly or hook their tails onto seaweed to hold their bodies in place in the currents.
Seahorses can be found around the world. They thrive in tropical and temperate water, and love living in and among coral reefs, seagrasses, and mangrove forests. There are 53 different species of seahorses according to the world registry of Marine Species.
