Brachiopods are characterized by being solitary, bivalved, bilaterally symmetrical coelomates. A ciliated, filament-bearing lophophore occupies much of the mantle cavity of all living representatives and functions as the principal food-gathering and respiratory organ of the animal. The coelom is divided into two principal spaces. The largest one is the posteriorly located metacoel that forms the body cavity and encloses most of the organs. The smaller mesocoel is the coelomic space inside the lophophore.