The family of Cnidarians consists of jellyfish, sea anemones and corals, and hydroids and siphonophores. The Cnidarian family includes familiar species such as moon jellies and sea urchins as well as exotic red corals and poisonous jellyfish such as Man-o-Wars. These categories are further broken down into smaller groups that contain subspecies and variations of breeds.
The class of corals includes hexacorals and octocorals. The most prominent examples of octocorals are fan corals, which have tree-like frames complete with tall and thick branches. In some corals, such as bamboo corals, frames are jointed and may be soft or hard to the touch. While octocorals are made of many tiny organisms grouped together, hexacorals live as single, solitary organisms with a single body unit. Jellyfish are classified into three subcategories: swimming, stalked and boxed. Included in the class of swimming jellyfish are moon jellies, which are transparent organisms that contain four distinct sex organs. Moon jellyfish often travel in large groups for protection, and it is not uncommon to find hundreds washed up on the shore at once. Lipkea is an example of a stalked jellyfish: like others in its class, this species lives in caves and on man-made structures in harbor areas. These jellyfish can crawl and somersault but lack the ability to swim.