Polymorphism in Siphonophora

Each Siphonophora originates in an inverted axial polyp. The pedal end of the polyp is inverted to form a gas-filled float called a pneumatophore. The opposite end of the axial polyp bears the mouth, sometimes with a single tentacle. The colonial zooids develop as lateral buds from the elongated axial polyp. The buds arise as sets or series called cormidia. Each conidium consists of usually a gastrozooid for feeding purposes, gonozooids for reproduction, dactylozooids for defense, and bract for protection.