Placozoans have been found only in shallow, nearshore, tropical and subtropical marine environments between approximately 30 degrees north and south of the Equator. Within these habitats, they tend to be absent from areas of high current and from bare sand bottoms. Because they are very sensitive to reductions in salinity, they will presumably not be found in fresh or brackish water or seasonally in areas that are subjected to heavy monsoon rains. (Ball and Miller 2010 and references therein; Eitel and Schierwater 2010) They are often found on mangrove tree roots, reefs, boat docks in the eulittoral and littoral zone, and around stony beaches (Eitel and Schierwater 2010). They can be abundant on coral reefs. Although placozoans have long been viewed as benthic organisms, Pearse and Voigt (2007) had more success collecting them on glass slides suspended 20 to 60 cm above the bottom than on glass slides situated on the bottom itself.