Starfish
Starfish is the most representative class of echinoderms in terms of structural physiology, with a flattened body, mostly five-radial symmetry, and a poorly demarcated body disk and carapace.
Starfish and sea cucumbers, sea urchins and other echinoderms, they usually have five carapace, but also four or six, body flattened, mostly star-shaped.
The diameter of the body of starfish is generally around 12-24 centimeters, but the size varies greatly among species, with a range of 1-80 centimeters in diameter.