The particulate matter oysters remove are sand, clay, silt, detritus, and phytoplankton. Its food consists of crustacean larvae, small copepods, diatoms, algae and detritus. They are omnivorous and feed on plankton, invertebrates, plant material and detritus. Rotifers eat particulate organic detritus, dead bacteria, algae, and protozoans. Soil invertebrates enhance fungal activity by breaking down detritus. Mysids are filter feeders, omnivores that feed on algae, detritus and zooplankton. Flower urchins feed on algae, bryozoans, and organic detritus. They also house predatory zooplankton which help break down detritus and control algae populations. It feeds on algae, bryozoans, and organic detritus. The majority of Mysida are omnivores, feeding on algae, detritus, and zooplankton. Some starfish are not pure carnivores, supplementing their diets with algae or organic detritus. Some insect larvae feed on the detritus. Others are scavengers and feeders on detritus. Organisms whose diet consists of plant detritus, such as earthworms, are termed detritivores. The critically endangered Shelta Cave crayfish feeds on guano and other detritus.