<P> The polyp colony reproduces asexually . During this stage of life , Obelia are confined to substrate surfaces . On this mature colony there are individual hydranths called gastrozooids , which can be found expanded or contracted , to aid in the growth of this organism by feeding ; the reproductive polyp gonozooids has medusa buds . Other hydranths are specialized for defense . The main stalky body of the colony is composed of a coenosarc , which is covered by a protective perisarc . </P>
<P> The polyp colony reproduces asexually . During this stage of life , Obelia are confined to substrate surfaces . On this mature colony there are individual hydranths called gastrozooids , which can be found expanded or contracted , to aid in the growth of this organism by feeding ; the reproductive polyp gonozooids has medusa buds . Other hydranths are specialized for defense . The main stalky body of the colony is composed of a coenosarc , which is covered by a protective perisarc . </P>
various types of zooids found in obelia colony
various types of zooids found in obelia colony
gastrozooids gonozooids
gastrozooids gonozooids