Photo by James W. Fatherree, M.Sc. (as published in his December 2010 Advanced Aquarist article: “Crabs in the Marine Aquarium”)

Here is an uncommon video of a common blue-legged hermit crab in the act of changing shells.  Don’t blink … the swap transpires in about one second (a little after the 1:00 mark).  Hermit crabs do not build their own shells, so make sure to provide your hermit crabs additional shells for them to move into as they grow.

http://www.youtube.com/watch?v=UhyQT5Jua00

original thread: http://www.3reef.com/forums/show-off-your-fish-tanks/caught-my-crab-video-changing-shells-106823.html