Abstract: A device for breeding fish and the like in open sea or lake in at least a netted bag (12), which at its upper part is supported by a pontoon (11), the depth position of which is variable. The purpose is to provide a breeding device which on one hand allows an upper cover also for very big bags, and on the other hand can be boarded also by bigger ships and independent of the wind conditions, and furthermore is designed thus that the taking up of fish can be carried out in simple way without bigger manual work.