How are cnidarians different than other animals?

1 Answer
Jan 17, 2018

Cnidarians are distinguished from all other animals by having cnidocytes, that fire like harpoons and are used mainly to capture prey.

Explanation:

All cnidarians are characterised by radially symmetrical body plans. They possess only one digestive opening, which serves as both the mouth and the anus. It is surrounded by tentacles and leads to an internal gastrovascular cavity.

They may exist as polyps (fixed) or medusas (free swimming). Some exist as colonies (obelia) while others live solitary (hydra).

Cnidarians have two main layers of cells the outer protective epidermis and the inner digestive gastrodermis. Sandwiched between these is the jelly like middle layer called mesoglea.

Unlike more advanced animal phyla, cnidarians lack a central nervous system and true muscle cells.