For your next party, consider a "disco clam"? These clams have flashy lips that they move frequently to create a "disco ball" effect. Scientists at UC Berkeley (hey! I know Lindsay!) recently determined that this is not bioluminescence (as found in some animals such as jellyfish) but because the lip has highly reflective cells on one side. They still don't know why the disco clam has flashy lips, but mate attraction is always a good guess. Read more and see a video here (in an article by another UCB scientist, and my friend Jane Hu)!