Kreuzungsexperimente an Laminaria saccharina von Helgoland und von der Isle of Man

Abstract

The brown alga Laminaria saccharina growing at Helgoland (North Sea) has smooth blades, whereas the blades of the same species occurring at the Isle of Man are covered with deep bullations. Gametophytes of both morphological types were grown in the laboratory and the resulting sporophytes of each type as well as hybrids were planted out in the sublittoral zone of Helgoland for four months. The Isle of Man type and the hybrids both formed bullations. The Isle of Man type differed further from the Helgoland type in that it had broader blades and did not tolerate the water temperatures above 14° C which prevail near Helgoland in summer. All experimental plants were removed from the sea before the blades became sporogenous. © 1975 Biologischen Anstalt Helgoland.