Seastar Wrap Up

This summer for my research, I was seeing the effects of changes in maternal investment in seastars. I was looking at what the effects of cutting the egg size in half would have on the size of the juvenile seastar after metamorphosis and the time it took the larva to develop into a juvenile. We started the summer looking at multiple species of seastars, but in the end we were only able to collects data from Pisaster, a species found on the west coast. Pisaster have small, planktotrophic developing eggs, but their eggs are on the larger side of the planktotrophic marine invertebrates.

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Slimey Seastars

Hi again! The last time I left you I mentioned a new experiment I would be starting on the seastar, Pteraster tesselatus.  Pteraster are commonly called the slime star because when agitated they produce massive amounts of a clear slime. Unlike the Pisaster and Evasterias, Pteraster do not have a feeding larval stage. Instead, Pteraster embryos hatch into larvae that do not feed before they settle and undergo metamorphosis to become a juvenile. There is not a large history of Pteraster research, especially in egg size manipulations, and I have never worked on this species before. Since it can be very difficult to work with this species, before we could do any true experiment to manipulate egg size, we had to make sure we would be able to spawn and fertilize the eggs.

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