The sea dragon, also known as poplar fish and tube mouth fish. It is a kind of bony fish, which is categorized into one family in zoological classification - the family of sea dragons. There are more than 150 species in the family, and some say there are 200 species. There are 25 species of sea dragons in China. Sea dragons are related to seahorses. Both are creatures of the family Hylidae, the order of spiny fishes.

Seahorses (Latin name: hippocampus), is the spiny fish order Hylidae warm sea several species of small fish collectively, is a small marine animals, body length 5-30 centimeters. Named for the curved head and body at nearly right angles, the head is a horse's head and form an angle with the body, the muzzle is long and tubular, the mouth is small, the dorsal fins are one, are composed of fins. The eyes can each move independently.

The sea dragon is related to the seahorse. Both are creatures of the family Hylidae of the order Spiny Fish. Seahorses and sea dragons have the same flavor and function, but sea dragons are more potent than sea horses.