Some encrusting bryozoan colonies with mineralized exoskeletons look very like small corals. This chiton is a grazer that feeds on encrusting or filamentous algae and possibly bryozoans. The larvae of "Acropora millepora" preferentially settle on vertical surfaces and on encrusting coralline algae. Feeds on hydroids and other encrusting fauna. A non-obligate symbiosis is seen in encrusting bryozoans and hermit crabs. It feeds on encrusting sponges, detritus or small invertebrates. As sessile encrusting organisms, the corallines are prone to overgrowth by other "fouling" algae. The mouthparts are designed for rasping and "E. esculentus" feeds on algae and encrusting invertebrates. The juvenile sponges are encrusting at first. Fire coral has several common growth forms; these include branching, plate, and encrusting. The colony shapes range from simple encrusting sheets to erect branching and even unattached forms. Early fossils are mainly of erect forms, but encrusting forms gradually became dominant. Most colonies probably start as encrusting forms and adopt a branching structure as they grow. Growth morphologies for the genus "Montipora" include submassive, laminar, foliaceous, encrusting, and branching. These colonies adopt a range of massive, branching, leaf-like and encrusting forms.