Other species focus on sessile benthic invertebrates; sponges, tunicates, bryozoans, and hydroids are staples. Fossils include brachiopods, gastropods, bryozoans, and tentaculites. The locality is also rich in crinoids, gastropods, bivalves, brachiopods and bryozoans. During the Carboniferous, brachiopods, bryozoans, and corals inhabited. Other taxa to suffer declines in diversity include brachiopods, bryozoans, crinoids, and ostracodes. It feeds on sponges, algae, bryozoans, zoantharians, gorgonians and tunicates. Bivalves, bryozoans, and gastropods also sustained heavy losses. Other predators on marine bryozoans include fish, sea urchins, pycnogonids, crustaceans, mites and starfish. A non-obligate symbiosis is seen in encrusting bryozoans and hermit crabs. Unlike modern reef growths, the Permian reef contained bryozoans, sponges, and other microorganisms. Flower urchins feed on algae, bryozoans, and organic detritus. They were previously classified as extinct corals, bryozoans, algae, stromatoporoids and sclerosponges. They feed on the corals, sponges, and bryozoans that litter the seabed. Freshwater bryozoans are preyed on by snails, insects, and fish. It feeds on algae, bryozoans, and organic detritus.