• Small, solitary, free swimming and pelagic sexual zooids arising from obelia colony.

• Umbrella like, transparent and gelatinous body.

• Body is divided into upper ex-umbrellar and lower sub-umbrellar surfaces.

• Presence of velum or craspedon.

• Presence of marginal tentacles.

• Gastro vascular cavity for digestion and circulation.

• Presence of marginal sensory structures called Statocysts.

• Obelia medusa are gonochoric or dioecious.