Seahorse is the name of 54 small marine fishes in the genus Hippocampus. "Seahorse" comes from ancient Greek hippo, which means "horse", and Campos "sea monster". The word "sea horse" can also be written as two separate words (seahorse) or hyphen (sea horse). The head and neck of the seahorse suggest a horse, with segmented bony armor, an upright posture, and a curly tail.

Seahorses are mainly distributed in tropical and temperate shallow water areas of about 45 ° s to 45 ° n around the world and live in sheltered areas such as seagrass beds, estuaries, coral reefs or mangroves. From North America to South America, four species have been found in the Pacific waters. In the Atlantic, Homo erectus ranges from Nova Scotia to Uruguay. H. Zosterae, known as the dwarf seahorse, was found in the Bahamas.

Colonies were found in European waters such as the Thames estuary.

There are three kinds of fish in the Mediterranean: H. Guttulatus, H. Hippocampus (short snout hippocampus) and f.cus (hippocampus). These species make up territory; the male habitat is within 1 square meter (11 square feet), while the female habitat is 100 times larger.