feeding assays with meredith

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!