A system of fattening for molluscs having supporting frames with first coupling members for the uprights that make up components and, carriers of the breeding compartments, and second coupling members on the flotation tubes of a moveable platform. The members and the uprights have aligned openings and that are actuated by removable coupling devices allowing the uprights to be attached or uncoupled. A crossbar, with an arrangement of connectors, keeps the components and provides an easily handled module that can be separated from the supporting frame along with the breeding compartments.