Most corals live in colonies. In some species, the individual animals conjoin themselves in a single mass: While others live as collections of separate polyps joined at the bases. Palythoas (like the coral pictured above) and zoanthid species are among the types that live as separate, conjoined polyps. The colonies normally spread by forming new polyps around the outside edges of the existing colony mass. The colony gets larger and wider over time, until the polyps form a bushy-looking cluster like the brown and teal ones in the photo. But not always. Like many other coral species, a palythoa polyp
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