Macrodasyida

An order of the phylum Gastrotricha. They inhabit marine or brackish waters, seldom fresh waters. Some do not exceed 0.5 mm (0.02 in.) in length, and most are not more than 1–1.5 mm (0.04–0.06 in.); these live in clean to detritus-rich marine sands of littoral or sublittoral areas. All have front and rear groups of adhesive tubes; most also have tubes along their sides. Some have cuticular thickenings or scales or hooks. Turbanella and Tetranchyroderma are the most common and most abundant of macrodasyids, with numbers of 50–100 per cubic centimeter of sand (800–1600 per cubic inch) not being unusual. See also Gastrotricha.