Today postdocs Martino Malerba and Giulia Ghedini spent the day investigating if the size of algal cells will affect the grazing rates and total amount ingested for the filter feeding bryozoan Bugula neritina.
To do this they used large and small cells that had been generated through artificial selection of the microalga Dunaliella tertiolecta and added either equal volumes or cell numbers of each size class to vials containing Bugula. These vials were kept on a roller system to ensure that algal cells didn’t sink and become unavailable for feeding.
Giulia took samples every half an hour for two hours from each of the 60 vials, with the help of volunteer Blake Chan, who then had to run the samples over to Martino who was waiting in a separate building.
Once Martino had the samples he was able to put them through a high-tech flow cytometer and get accurate measurements of the number of algal cells for more than 300 samples.
From the data the team will be able to work out whether the Bugula have consumed more cells of a certain size and whether this equates to a greater overall amount of algal biomass consumed.
This work forms part of a larger program that is investigating whether (and in what way) evolution in size of one species can effect another species.