Seahorse is the title given to 54 species of marine fish in the genus Hippocampus. “Hippocampus” comes from the Ancient Greek hippos meaning “horse” and kampos meaning “sea monster”. Seahorses range in size from 0.6 to 14 in (1.5 to 35.5 cm). They are named for their equine appearance. Although they are bony fish, they do not have scales but rather thin skin stretched over a series of bony plates, which are arranged in rings throughout their body. Each species has a distinct number of rings. Seahorses swim upright, another characteristic that is not shared by their close pipefish relatives, who swim horizontally. Razorfish are the only other fish that swim vertically like a seahorse. Unusual among fish, seahorses have a flexible, well-defined neck. They also sport a coronet on the head, which is distinct for each individual.