1. Cultivation of marine animals in the open sea requires development of special equipment. The trichterkreisel facilitates maintenance and cultivation of several marine animals (Homarus gammarus, Galathea squamifera, Mytilus edulis, and others). It represents, in essence, an upright standing cylinder, into which tidal currents enter at the bottom, rotate and slowly leave at the top through a gauze cover. 2. Small plankton organisms enter the trichterkreisel with the water flow, passing through gauze-covered frames and thus provide food for the animals cultivated. Some of the plankton forms metamorphose and grow in the device until devoured. 3. During a 17 months' experiment a young lobsterHomarus gammarus grew at a normal rate in a trichterkreisel without any artificial feeding. A large in situ trichterkreisel for cultivating masses of lobster larvae is planned for the near future.