picture of a Blue Dorid nudibranch

This beautiful
translucent Blue Dorid nudibranch is in the process of laying an egg coil. The eggs are often deposited on the nudibranch's favorite food; in this case, a sponge. The veliger (larvae) is free-swimming until encountering a suitable shallow reef surface; sometimes the metamorphosis into a juvenile is delayed until the veliger finds its proper food source.

Identification: Hypselodoris bullocki (recently reclassified from Chromodoris to Hypselodoris)

see two more images, in the more common color variation of H. bullocki:
blue dorid #2 [101K]
blue dorid #2 [101K]
blue dorid nudibranch #3 [132K]
blue dorid #3 [132K]