Which of the following groups does hydra belong to?
Cnidaria
The hydra belongs to the group Cnidaria. They have no vertebral column and are diploblastic.
The identifying characters of a hydra are,
i) It is aquatic and seen in the freshwater.
ii) It has a microscopic body which is composed of two layers - ectoderm and endoderm which is separated by a non-cellular mesoglea.
iii) There are many tentacles surrounding the mouth, no anus, mouth acts for both ingestion and egestion.
iv) The body cavity is a single coelenteron.
v) An adhesive pedal disc is present, body with cnidoblast cells.