1. Cockroach has a body cavity or true coelom present around the viscera.
2. The body cavity of cockroach is known as haemocoel as it is filled with haemolymph (blood). Cockroaches have open type of circulation thus; the body cavity is filled with haemolymph.
3. The body cavity contains fat bodies. These are in the form of loose, whitish mass of tissue. They are made up of large, polygonal cells which contain fat globules, proteins and sometimes glycogen.