This is from Milky Way Scientists (a Facebook site you really should join) via Matthew Cobb:
Scientists at the New Zealand Marine Studies Centre placed glass shells into a hermit crab tank. The crabs soon moved into the glass shells and made themselves comfortable, allowing researchers to take these amazing photographs.
There’s only one photo, but it’s cool:
Hermit crabs must change their shells as they molt and grow; here’s a video of the decisive moment when one moves house. The change is made very quickly, for the animal’s soft and vulnerable abdomen must not be exposed for long:
Read more about hermit crabs here. Some can live 23 years in captivity.
Wonderful creatures. I used to drive my small children a few miles to a rocky Northumberland beach whose rock pools are home to hundreds of tiny hermit crabs. We’d collect a handful of empty winkle shells and put them in reach, then watch the crabs swiftly trying out each shell until they found one, I suppose, with just the right amount of growing space.
I love the glass shell; hope the new occupant isn’t unduly photosensitive.
How does the hermit know if non-glass shells are vacant? What about predatory lenders? Are there itemized deductions for mortgage interest on a 2nd shell?
The glass hermit crab shells have been around a while. You can buy them if you keep hermits as pets http://www.glassshell.com
I understand that hermit crabs are a rather “talkative” lot, making a lot of noise especially at night. Is this true?
I didn’t realize the this crab’s tail was so soft. You would almost think it was missing part of the exoskeleton.
That’s kind of the point. By using second-hand shells, they save the expense of building shells of their own and discarding them at each molt.
And it’s not the tail; it’s the body.
the hermit crab’s new clothes
Weird question I never thought about before: how do they poop?
I kinda had the same question. Maybe that’s the real reason they change shells?
Here’s a video of one moving around in its glass shell: youtube.com/watch?feature=fvwp&NR=1&v=DaU5etPejZA
Thinking about how they evolved – what was the ancestral crab like? Did a genetic error mean an individual had a soft body, or is it to do with how the free swimming larvae developed…? So many questions!
Wow – King crabs went the other way, from shell living hermits to having a hard carapace –
http://www.nature.com/nature/journal/v355/n6360/abs/355539a0.html
…and Birgus latro the coconut crab, is a hermit crab (family)! And massive – “Coconut crabs may be responsible for the disappearance of Amelia Earhart’s remains” says Wikipedia.