Write a short note on Hydra.

Explanation

The common name of Hydra is fresh water polyp. Hydra occurs in clear fresh water ponds, pools, lakes and streams. Characters : Hydra is tubular thread like animal. It has radial symmetry. Hydra is generally green or brown. It is attached to aquatic vegetation with the help of its pedal disc. Locomotion occurs by looping, walking, floating, climbing and swimming. The oral end has a mouth at the tip of conical hypostome.
The base of hypostome bears a ring of 5-10 hollow tentacles. The body wall consists epidermis and gastrodermis. Hydra is carnivorous and feeds on small animals like crustaceans, insect larvae and newly hatched tadpole. Digestion is both intercellular and intracellular. Hydra is famous for its remarkable power of regeneration. Asexual reproduction occurs by budding. Hydra is monoecious and cross fertilization occurs in it. Development is direct i.e., without larval stage.