Science
Related: About this forumHermit Crabs Line Up By Size to Exchange Shells
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 isnt second-best, its 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 suns punishing rays, if they arent 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, theres a big to-do.
When a hermit crab spots a new shell, itll 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 its 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
(38,613 posts)roguevalley
(40,656 posts)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
(115,681 posts)Kalidurga
(14,177 posts)I wanted to give it a shell.
Laffy Kat
(16,391 posts)That made my night. (Admittedly, however, not too much happened this evening.)
Thespian2
(2,741 posts)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
(3,414 posts)from the article:
The housing market for hermit crabs isnt 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
(55,981 posts)Last edited Sun Mar 15, 2015, 10:44 AM - Edit history (1)
the largest crab would devour the smaller crabs.
DeSwiss
(27,137 posts)BlancheSplanchnik
(20,219 posts)SKWEEEEEEEEEEE!
freshwest
(53,661 posts)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.