(Cestus veneris), a marine animal of the phylum Ctenophora. The body shape is a flat, jelly-like band approximately 1.5 m long. The animal has a slitlike mouth in the middle along the narrow margin of this band and an aboral organ (organ of equilibrium) along the other narrow margin. There are eight rows of ctenii (plates)—four long ones extending along the body and four short ones. Venus’s-girdle swims bending the body in a serpentine fashion and moving the ctenii. It can be luminescent in the dark. Widespread in tropical waters, it is not found in the seas of the USSR.