I've finished up working for Erik and am headed off to a new job! The undergraduates, Paige Bippus and Sarah Shainker will be taking over most of the Gracilaria culturing that I've been doing. Thanks for everything! It's been fun!

We broke down the feeding assay with Diopatra, Ulva, and the chemical extracts of Gracilaria! We found that there was no difference in the amount of Ulva the worms ate with Gracilaria chemicals painted on it and without Gracilaria chemicals. This tells us that the Gracilaria chemicals may not be preventing the worms from eating it. These results do not explain why the worms do not like to eat Gracilaria, so there are still questions to be answered! 

I am currently running a feeding assay with the decorator worm, Diopatra cuprea, to see how they respond to the chemistry of Gracilaria. Diopatra live in tubes that they build and "decorate" with what is in their environments. Usually bits of shell, Gracilaria, and Ulva are found attached to Diopatra tubes. Many seaweeds will produce chemicals that make them taste bad to herbivores and act as a defense. The worms love to eat Ulva, but they do not seem to like eating Gracilaria and we want to know why. To determine if Gracilaria has chemicals that keep Diopatra from wanting to eat it, we first extracted the chemicals from Gracilaria using Ethyl Acetate. Then, we set up a feeding assay to compare how much Ulva the worms will eat when it is coated with just Ethyl Acetate and how much Ulva the worms will eat when it is coated with Ethyl Acetate and Gracilaria chemicals. This method allows us to find out if the chemicals of Gracilaria deter feeding by Diopatra. Since we know that the worms like to eat Ulva, if they eat less of the Ulva when it has chemicals from Gracilaria, this will indicate that the chemistry produced by Gracilaria is protecting it from herbivores such as Diopatra. Stay tuned for the results of the feeding assay!

 This past week I broke down the Gracilaria growth experiment! After two weeks of growing Gracilaria attached to different structures we found that the Gracilaria that grew in the hollow tubes with mesh on each end grew the best.  Next, I will be researching how other scientists have grown Gracilaria in the lab before setting up another experiment to look at how salinity influences algae growth. 

This past week, I have been setting up tanks to grow Gracilaria in the lab. First, we are attaching Gracilaria to three different structures to determine which method allows the Gracilaria to grow the best. These structures are a white plastic grid, a PVC frame, and hollow tubes with mesh on the ends to allow water to flow through. We also wanted to know if the Gracilaria grows better when we bubble air into the water or when water is pumped over the seaweed. To determine which methods allow the greatest growth, we are growing the Gracilaria in the lab for two weeks. Once we know which method works the best, we will be starting more experiments to figure out how well Gracilaria grows under different environmental conditions.