Why don't starfish have brain?

5 ANSWERS

1. Guest5427
   

   because it is made up of nerve cells that control it's functions

   Report (0) (0)  |   12 years, 7 month(s) ago  

2. Guest5924
   

   Echinoderms have rather complex nervous systems, but lack a true centralized brain. All echinoderms have a network of interlacing nerves called a nerve plexus which lies within as well as below the skin. The esophagus is also surrounded by a number of nerve rings which send radial nerves that are often parallel with the branches of the water vascular system. The ring nerves and radial nerves coordinate the sea star's balance and directional systems. Although the echinoderms do not have many well-defined sensory inputs, they are sensitive to touch, light, temperature, orientation, and the status of water around them. The tube feet, spines, and pedicellariae found on sea stars are sensitive to touch, while eyespots on the ends of the rays are light-sensitive.

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3. Guest1737
   

   Starfish don't have a brain in the traditional sense that you are thinking of, but they do have a nervous system. They have a decentralized nervous system that, unlike mammals, is spread throughout their body, instead of being in concentrated in one specific region.

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4. Guest3257
   

   they dont have a head!! so theres no space manufactured :P

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5. Guest9274
   

   I think its because they dont have faces and because they dont do anything anyways, so why do they need brains?

   Report (0) (0)  |   12 years, 7 month(s) ago