In the early 1980s, a biologist at the tropical aquarium in Stuttgart, Germany, noticed that the beautiful green alga Caulerpa taxifolia (Fig. 1) would make an ideal aquarium decoration. It does not wither, it is fast growing and it withstands cool temperatures. In the following years, many aquariums acquired Caulerpa plants from Stuttgart, among them the Oceanographic Museum of Monaco, from wh...