• Question: how does it work without a brain

    Asked by em10 to Common starfish on 10 Nov 2017. This question was also asked by spaghettibolognese.
    • Photo: Common Starfish

      Common Starfish answered on 10 Nov 2017:

      common starfish don’t have a brain. But they have a nervous system, mainly including a circumoral nerve ring and five radial nerve cord. They also have hormones, and more than 40 neuropeptides have been identified in common starfish, which are involved in the behaviour of starfish.

Comments

  • Photo: Common starfish

    Common starfish commented on :

    The nervous system of starfish is just as complicated as the nervous system of many other invertebrates (e.g. snails, worms etc). The difference is that starfish don’t have a head and if you don’t have a head you don’t have a brain!! Right?
    However, any of the 5 arms can become the leading arm when they move, so the radial nerve cord in that arm takes on the role of a “brain” when that arm is leading. So maybe we can think of them having 5 “brains”!!! (Maurice Elphick)

  • Photo: Baltic clam

    Baltic clam commented on :

    clams dont have heads either, so they are also missing a ‘brain’