When a scale is plucked from a killifish (Fundulus heteroclitus), it is surrounded by thin layers of tissue. Biology student Hilary Genise peeled the attached tissue off of the scale, and cultured it. In her time-lapse video, you can see individual cells begin to migrate away from the large mass of tissue. Events are speeded up 120 times.

This video was made by Alexandria Younossi, a student in Bio 305 (fall 1999). Sea urchin eggs were fertilized and the embryos raised in seawater until the gastrulae were swimming around in the dish. The following movie is of older embryos, at a higher magnification. The sea urchin larvae had reached the pluteus larval stage. The word pluteus (plutei = plural) comes from the German word for easel. While filming the plutei, Alexandria rotated the polarizing filter. When the background is dark, the two polarizing filters are at cross angles, and the skeletal rods are most visible. When the polarizer is rotated so that the background is light, much more of the actual embryonic tissues are visible (ectoderm, gut, etc.).

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