Marine Wildlife Encyclopedia
Coralline Sponge Vaceletia ospreyensis
Vaceletia ospreyensis is a living member of the coralline sponges group, most of which are known only from fossils. Coralline sponges have a massive skeleton made of calcium carbonate, as well as silica spicules and organic fibers. They were the dominant reef-building organisms before the stony corals of modern reefs evolved. Although given a separate class here, the Sclerospongiae, it is quite possible that coralline sponges belong to the class Demospongiae.