Other polymorphs Spinozooids are hollow, movable spines, like very slender, small tubes, present on the surface of colonies, which probably are for defense. Some species have miniature nanozooids with small single-tentacled polypides, and these may grow on other zooids or within the body walls of autozooids that have degenerated.
Other pOLYmoRpHs spInozOoIds are hOLloW MOVAblE spIneS Like verY sleNDer SmaLl tUbeS prESENt on the SuRFAcE Of colonies wHich pRoBABLY are for defEnSe sOMe specIes HAVE MiNiatuRE nAnoZooIDS wIth Small sIngle-tenTAcled PoLypiDES and theSe mAy gRow on otheR zoOids oR Within The body wallS of AutOzoOids that haVe DegenerAted