Sponges and Cnidarians

Sponges

Sponges are from the phylum Porifera. They are multicellular organisms that have bodies full of pores and channels that allow water to circulate through them. They do not have nervous, digestive, or circulatory systems.

Cnidarians

Cnidaria is a phylum containing over 10,000 species of animals found exclusively in aquatic (freshwater and marine) environments: they are predominantly marine species. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. They have two basic body forms: swimming medusae and sessilepolyps, both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes.
Sponges and Cnidarians
Sponges and Cnidarians