Comments of Obelia
Distribution:-
Obelia found from arctic region to the Gulf of Mexico and the pacific coast and from southern California to Oregan.
Habit and Habitat:-
Obelia is a colonial, marine sedentray hydrozoan zoophyte found attached on piles , rocks and seaweeds in shallow water.
Characteristics:-
1) Obelia is a colony.
2) The colony consists of a basal horizontal portion, the hydrorhiza which is attached with the substratum and a number of vertical branches known as hydrocauli.
3) The hydrorhiza and hydrocauli are covered by a chitinous perisarc which encloses soft inner coenosarc.
4) The colony is trimorphic having three types of zoids, e.g hydranth, blastostyle and medusa.
5) Blastostyle zooild in club-shaped without mouth and tentacles.
6) Medusa is bell shaped with a concave and a convex side.
Economic Importance:-
1) Obelia is used in many zoology textbooks to exemplify the Hydrozoa Life Cycle.
2) Obelia is useful for laboratory research.
3) Museum specimen.
4) Nematocysts can penetrate human skin.
Diagram of obelia
obelia