The eggs hatched last Monday (10/5/15), but I am finally getting around to posting. Assuming you have a little imagination, you should be able to see some little veligers whizzing around among the very wiggly embryos. The hatchery was not ready for them (they only took about 5 days to hatch), so I just added the veligers directly to the growout tank and hoped for the best. Whatever this species is, it could be very useful in the lab to have embryonic development done in less than a week.
Meantime, I have added some fresh Bryopsis from a local reef tank, so maybe the E. clarki will be in the mood to lay eggs soo.
Two days later, the embryos have started to spin in their eggs. The video below has been filtered somewhat to reduce noise, so they appear to be moving a little more slowly than in the raw data. Have a look in full screen mode for the complete Elysia-in-motion experience.