There are 1600 extant species and 300 fossil species, and the more colorful ones are generally poisonous.

Starfish are the most representative group of echinoderms in terms of structural physiology. Body flat, mostly five radial symmetry, body disk and wrist demarcation is not obvious. The mouth faces downward when living, and the opposite mouth faces upward. The ventral side of the carpus is characterized by a step-band groove, within which the tube feet protrude. The bony plates of the endoskeleton are connected by connective tissue and are flexible and bendable.

The starfish contains a large amount of protein, amino acids, unsaturated fatty acids, calcium, iron, phosphorus and other conventional substances, but also contains starfish saponin, starfish saponin and other substances with special effects.

The content of unsaturated fatty acids in the starfish and sharks and other comparisons are not very high, but also too much higher than animals grown on land, suitable for the elderly to eat in moderation, can enhance memory, brain and brain.

Most of the components of the starfish are proteins, and belong to the animal protein, after decomposition and the human body's amino acid ratio is very close to the body, suitable for weak people to eat in moderation, can play a complementary effect of the health of the body.