At the end of November, I spent a week at Roskilde University in Denmark.
By invitation from fellow marine botanist professor Morten Foldager Pedersen, I went there to start up an experiment on Fucus radicans together with his PhD-student Tiina Salo.
Fucus radicans is named after its ability to reproduce asexually by fragmentation. Radicans is latin for “root-forming”, and although algae do not have roots, they form root-like attachments to the substrate, called rhizoids. So, when a small fragment falls off the mother algae, it can re-attach and form a new thallus, which is a genetically exact copy of its “mother”, i.e a clone.
A fragment of Fucus radicans has formed new rhizoids, attaching to the bottom of a petri dish.
To reproduce in this way is not very common within the Fucus-family. We do not know what favours this mode of reproduction, unlike the sexual reproduction where we know that salinity plays a major role, but light and temperature is also important.
So, in order to find out how Fucus radicans has the best non-sexual reproduction, we designed the experiment in Roskilde.
The parameters we have decided to try are light, temperature and water movement.
Together with Tiina, I spent the better part of the week in the basement of the Biology department, in a temperate chamber filled with algae, sea urchins, a hard-at-work master student and the all-time favourite combination of electricity and water.
The light box is fitted over one of our white tanks.
In order to decide if any of our tested parameters, alone or in any combination, contributes to the formation of rhizoids, you have to plan the setup so that the results can be testad statistically. This means that you have to think hard before you start the experiment, so that you can use the data to actually answer your initial question. I’m in luck. Tiina is a total wiz when it comes to statistics, and two heads are better than one.
To the right can be seen the heater (square box) and the cooler (spiral).
I had brought some Fucus radicans from some different localities with me to Roskilde. We picked off small fragments, no bigger than 1 cm, and placed them on tiles. Tiina bought them at Bauhaus and had had the same experience as me. Why is it considered strange to be more interested in the back of a tile?
Four small fragments on a tile.
Finally, we were all set and could switch on the electricity again. We’ll leave it for approximately seven weeks, then I’ll go back and check the result. Meanwhile, wee keep our fingers crossed, hoping that the seaweed will cooperate and form nice new rhizoids. We’ll keep you updated.
It is fun to work with seaweed!
Baltic Sea Weed Blog 