Hermit Crabs Line Up By Size to Exchange Shells

[Panich52]

Discover D-brief

Anyone with an older brother or sister knows that clothes “shopping” often meant begrudgingly sifting through hand-me-downs rather than perusing the latest fashions at the mall.

But for hermit crabs, the hand-me-down system isn’t second-best, it’s a matter of life and death. And as a new clip from the BBC show Life Story shows, the swapping process is remarkably orderly.

Constantly Renovating

Hermit crabs need shells: without them, the critters will bake under the sun’s punishing rays, if they aren’t eaten first. The problem is hermit crabs are continually outgrowing their shells and the local real estate market is incredibly competitive. So when a spacious new shell washes up on shore, there’s a big to-do.

When a hermit crab spots a new shell, it’ll size up the shell for a good fit. If the shell is too big, the prospecting hermit crab will sit back and wait to steal the castoff shell of a larger crab that decides to upgrade. In the meantime, while the first crab waits, other crabs gather around the shell and do the same. When a crab large enough to fit the vacant shell arrives, a bit of orderly chaos ensues -- Video below.
https://vimeo.com/117375257/recommended
(looks like attempts to post vid failed. It's at link below)

The hermit crabs form a sort of conga line ordered from largest to smallest crab. As the largest crab enters its new home, the next crab in line takes the vacated shell, leaving an open shell for the crab behind him. The shell swapping continues down the line until everyone has upgraded. This chain reaction is called a vacancy chain, and it’s an ingenious way for the creatures to survive while sharing limited resources.

More
http://blogs.discovermagazine.com/d-brief/2015/03/09/elaborate-hermit-crab-shell-exchanges-aid-in-survival/?utm_source=SilverpopMailing&utm_medium=email&utm_campaign=DSC_News_150312_Final&utm_content=#5465

[arcane1]

1. How CUTE!!

[roguevalley]

5. I went to the Oregon coast once and got a great tiny shell. I was sitting on the couch when I got

home and emptied my pockets. The shell on the couch started to move. A tiny crab was inside. I still regret to this day I couldn't keep him alive. So cute, these guys. I like them.

[uppityperson]

2. That is very cool, thank you for posting it. Nature is amazing

[Kalidurga]

3. That little one

I wanted to give it a shell.

[Laffy Kat]

4. Who knew??

That made my night. (Admittedly, however, not too much happened this evening.)

[Thespian2]

6. Creatures in nature

are often more organized and better equipped to handle their environments than homo sapiens. Do hermit crabs have housing shortages? Could happen, but not because they made it happen.

[deek]

12. in the future, perhaps

from the article:

The housing market for hermit crabs isn’t going to get any less competitive if certain trends continue. Ocean acidification, an effect of rising atmospheric carbon dioxide, is changing pH levels of the tidal rock pools the crabs call home. Lower pH levels can make shells thinner and even seem to affect hermit crabs’ decision-making skills, making them discard suboptimal shells less readily.

http://blogs.discovermagazine.com/d-brief/2015/03/09/elaborate-hermit-crab-shell-exchanges-aid-in-survival/?utm_source=SilverpopMailing&utm_medium=email&utm_campaign=DSC_News_150312_Final&utm_content=#5465

[rhett o rick]

7. Wait just a minute. This sounds like socialism. In our capitalism

Last edited Sun Mar 15, 2015, 10:44 AM - Edit history (1)

the largest crab would devour the smaller crabs.

[DeSwiss]

8. And then rent out their empty shells. n/t

[BlancheSplanchnik]

9. omg, get out!!!!

SKWEEEEEEEEEEE!

[freshwest]

10. Can't see it on the link (computer issues) but found something like it:

Incredible footage of hermit crab changing shells with anemones!

Published on Jul 13, 2014

In this exciting excerpt from the third season of Jonathan Bird's Blue World, Jonathan films a hermit crab changing shells and then also transferring its anemones from one shell to the other. This is extremely rare footage of a seldom-seen behavior!

Link in the description leads to a longer video.

[eppur_se_muova]

11. You want to keep your own dashboard bobble-heads ... nt

[HuckleB]

13. K & R!

[Hekate]

14. Fascinating! KnR