EVERYDAY SCIENCE

Detailed explanation-1: -Cnidarians are incredibly diverse in form, as evidenced by colonial siphonophores, massive medusae and corals, feathery hydroids, and box jellies with complex eyes. Yet, these diverse animals are all armed with stinging cells called nematocysts.

Detailed explanation-2: -Nematocysts or cnidocysts represent the common feature of all cnidarians. They are large organelles produced from the Golgi apparatus as a secretory product within a specialized cell, the nematocyte or cnidocyte.

Detailed explanation-3: -nematocyst, minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g., jellyfish, corals, sea anemones).

Detailed explanation-4: -Cnidarians have a unique feature: stinging cells called cnidocytes (NID-uh-sites). Each cnidocyte cell has a long, coiled, tubular harpoon-like structure, called a nematocyst (Greek root word nema meaning thread; Greek root word cyst meaning bag).

Detailed explanation-5: -The phylum Cnidaria (pronounced “nih DARE ee uh”) includes soft-bodied stinging animals such as corals, sea anemones, and jellyfish (Fig. 3.23 A). The phylum’s name is derived from the Greek root word cnid-meaning nettle, a stinging plant. Cnidarians are found in many aquatic environments.