Cnidaria
Cnidaria is a phylum situated within the Animalia kingdom, encompassing a vast array of more than 11,000 aquatic species inhabiting both freshwater and marine environments. This diverse phylum includes various organisms such as jellyfish, hydroids, sea anemone, corals, and even some of the tiniest marine parasites.
Cnidaria is characterized by several distinct traits, including a decentralized nervous system that is dispersed throughout a gelatinous body. Additionally, these organisms feature specialized cells known as cnidocytes or cnidoblasts, equipped with ejectable flagella primarily used for capturing prey and for envenomation.
The body structure of Cnidaria consists of mesoglea, a non-living jelly-like substance, that is sandwiched between two layers of epithelium. Notably, these epithelial layers are typically comprised of cells only one layer thick.
