The Sea Lettuce Ulva only gets into shape with the right bacteria
The genus Ulva grows as a tube or a ‘lettuce’ flat, sheet-like blade, as shown for these species collected at the Portuguese coast. The interactions between the juvenile algae and bacteria can be studied under controlled conditions in the laboratory (right). Photos and © Thomas Wichard, University of Jena.
Ulva, a green seaweed found in oceans all over the world, has been selected ‘Alga of the Year 2015’. This ’sea lettuce’ either forms tubular ribbons or sheet-like (‘lettuce’) blades. Individuals commonly reach a size of approx. 20-30 cm. The specific ‘lettuce’ growth form of the alga only develops in association of bacteria which trigger differentiation and development. As Ulva requires the presence of these bacteria, it has developed special mechanisms to attract them. This requires an exchange of information between algae and bacteria. As the two organisms belong to two very different evolutionary groups, this process has fascinated chemists, biologists and algal researchers who now want to establish one Ulva species - namely Ulva mutabilis - as a future model organism.
