The 3 culturing devices described are based on the principle of the classic air-water lift, which facilitates continuous recirculation and aeration of the cultivation medium. The first device is a "circulation cylinder", convenient for hatching eggs of the brine shrimp Artemia salina and for culturing algae and protozoans. In the second device, an internal basket (i.e., a glass cylinder with plankton-gauze bottom) prevents the animals being carried along in the air-water lift. The third device, analogous to the second, is provided with a lateral waste-drain and a water collector with siphon, which empties regularly into the main culture vessel. The second and third devices proved to be excellent for the cultivation of a variety of aquatic metazoans. They fulfill two elementary principles of cultivation: food particles are kept in suspension and evenly distributed, and the necessary aeration is provided without injuring sensitive animals. |
