green serpent starfish

Question

I have a very large green serpent starfish(12 - 15 inch).  It developed a hole on its back which got bigger and bigger until the body disappeared and now I have 5 tenacles moving around independently and eating.  It is very weird.  I feed them pieces of shrimp and they curl around it but eventually let go of it since there is no body to feed.  My question is, do they regenerate or will they just die?  The tenacles look very healthy and sometimes two of them will twist together.
Thank you for any information you can offer.

Answer
Hi Nina. I have honestly never heard of a serpent star regenerating from a leg! Usually the central disc will split and can regenerate from that but it has to have part of the body attached to it in order to grow into a new starfish. As the name suggests, the arms of the brittle stars are rather liable to break. This is actually an escape mechanism. Those arms regenerate quickly and an entire new organism can regenerate, if the broken arm is attached to a sizable portion of the disk. Brittle stars can reproduce asexually by self-division. They will divide completely in half and two starfish will form out of the one. Keep an eye on those arms! If you notice any part of the central disc on them you may have a few new inhabitants in your tank. Also watch to make sure they don't die as they can pollute your tank!