Colony composed of uniserial chains of zooids, branching and spreading irregularly. Each zooid is made up two parts, with a lower part, usually encrusting a substrate, from which rises a erect tubular part containing the frontal membrane and operculum. The adnate part may be thin and threadlike, or expanding to a dilated zooid from small connecting tubes. The erect part of the zooid includes a cylindrical proximal zone, and a distal zone with the frontal membrane on one side, often on an expanded part of the zooid.
Calcification is delicate.
There are no avicularia. Embryos are brooded in external thin-walled ovisacs, which are rarely seen. A few records of this genus as a fossil are based upon preserved encrusting material, which is often of doubtful affinities. The Recent material is so thinly calcified that it is difficult to see preservation of this genus except under exceptional conditions. Most records of Aetea are from shallow-water or midshelf, but it can occur at greater depths.