Star fish have no brains!!

Star fish have no brains!! 

Sea stars or "starfish" are not fish and don't have any brain.They exhibit a superficially radial symmetry; typically have five "arms" which radiate from a central disk. However, the evolutionary ancestors of echinoderms are believed to have had bilateral symmetry. There are some 2,000 species of sea star living in all the world’s oceans, from tropical habitats to the cold seafloor.



Sea stars do not rely on a jointed, movable skeleton for support and locomotion, but instead possess a hydraulic water vascular system that aids in locomotion. The water vascular system has many projections called tube feet on the ventral face of the sea star's arms which function in locomotion and aid with feeding. Sea stars usually hunt for shelled animals such as oysters and clams. They have two stomachs. One stomach is used for digestion, and the second stomach can be extended outward to engulf and digest prey. This feature allows the sea star to hunt prey that is much larger than its mouth would otherwise allow. Sea stars are able to regenerate lost arms.


A new sea star may be regenerated from a single arm attached to a portion of the central disk. Sea stars are eaten by bottom-dwelling fish and crabs, as well as by sea gulls when low tides leave the sea stars exposed. Regeneration will occur as long as one fifth of the sea star's body remains intact. Sea stars breed in the spring, producing as many as 2,500,000 eggs. Females will feel plump and spongy when their arms are filled with eggs.


Sea star digestion is carried out in two stomachs in the mouth: the cardiac stomach and the pyloric stomach. The cardiac stomach is a sack like stomach located at the center of the body and may be everted out of the organism's body to engulf and digest food. Some species are able to use their water vascular systems to force open the shells of bivalve mollusks such as clams and mussels by injecting their stomachs into the shells