Hey Brie, perhaps you could do like what they do to milk cartons and perform some optical comparison to deterime weight gain or loss.
Meaning if you could place the star fish on the same rock and the camera in the same spot every time then you could put them side by side or even over lay the images and see if there is a difference in the width or gerth of a leg or something to that effect. Just an idea.
Oh and perhaps you could make a feeding platform for your star fish. What I'm thinking of is the lid to one of the very little disposible glad lock containers. The lids have a lip on the outside of them so that you could put it under water and then put the pellets on it. That should be a small enough diameter so that when you put the star fish on it (All underwater of course) the tangs and angles won't be able to get at the food because the star fishs center'll be covering it all.
Also, another thing would be to do a study on movement of the star fish. Because when you move him/her it'll be in "safe" mode for a certain lenght of time. So if you do that prior to food being available then you can gage how long "safe" mode is normally and then if the star fish is over the food plate you can time him/her. If the time is longer than the "safe" mode time it could be hypothsised that it is due to the star fish eating.
Also, how does the star fish react when the tang and angle are "stealing" food? Because every time they compete with him/her it might be causing him/her to go into safe mode for fear of predation.
Very interesting, I'll have to write some of this down so I can perform some studies when I have some free time, if ever.
Brian.
