NUDIBRANCH - INDONESIA - UNDERWATER - SHELL LESS SEA SNAIL ---------Nudibranch in latin means naked gill. The frills are the gill structure. A vast variety of species in a rainbow of fanciful colors can be found world wide. The nudibranch generally feeds on Hydroids and sponges that grow on the bottom. They will absorb the stinging devices of many Hydroids into their bodies and use them as a defensive mechanism against any predators. The bright colors are thought to be a warning signal to predators, I do not taste good, this is not a proven scientific fact as yet.