Curious and striking aquatic animal
The starfish is a striking marine animal that is not classified as a fish, but rather is closely related to sea urchins. It belongs to a completely different group from fish, known by the name of echinoderms.
There are approximately 1,500 to 2,000 species of starfish worldwide. These are animals that only live in the sea, only a few live in brackish water (less salty than the sea) and none in fresh water.
- Sea stars have radial symmetry, this means that they do not have a left and a right half, but instead have an oral side (where the mouth is) and an aboral side (opposite the oral side).
- They generally have 5 arms that arise from the central disc and can be long or short. But there are some species that can have more, up to 50 of them at most.
- The mouth is located just below the central disk of the starfish, on the side that is in contact with the surface.
- They have high capacity to regenerate their body. If they lose an arm, then they generate a new one. New stars can also be formed from the arms, because almost all the organs are located in these members.
- The skin of the starfish is hard and colored, they can be: Orange, red, blue, brown or gray. It can have a variety of textures, such as: Smooth, prickly, grainy, etc.
- Blood does not flow inside their body, but they have a system of water channels, through which they breathe, capture their prey and move.
- Sometimes they dump the stomach out of the mouth, in order to be able to consume larger prey.
- They have little eyes on each arm. However, the sight of these animals is not precise but they perceive light and darkness to be able to move in their environment.