Here’s another Attenborough video featuring the lifelong attempts of hermit crabs to find shells that fit them as they grow. A hermit crab without a shell is a pathetic thing (see several at 2:39), easily taken by predators or cooked by the sun. Here’s a stunning behavior in which a line of crabs forms in order of size, with the aim of each one swapping up to a bigger shell within a matter of minutes. Or course, the biggest crab needs an empty bigger shell to move into, which apparently is the case here. The picture of the lineup at 1:32 is fantastic.
The video comes from “Life Story,” part of the great BBC Earth series.
12 thoughts on “Sequential shell swaps in hermit crabs”
The music is dippy, but those crabs are adorable! I had no idea that they exhibit this behavior — I would have thought there were plenty of shells of all sizes available.
I wonder why did natural selection favor this instead of having their own shell grown like lobster or crabs?
Why go to the expense of growing your own shell when there are perfectly good shells littering the sea floor? Put your resources into reproduction. Just a guess.
…after all, that’s our strategy, more or less!
I now live in a house bigger than the previous one, and, true, I have one offspring to show for it.
Slightly off-topic, but David Attenborough recently came top in an opinion poll of who Brits were asked who their dream prime minister would be: https://www.standard.co.uk/news/uk/david-attenborough-named-as-uks-dream-prime-minister-a4337101.html
Hermit crab inequality apparently mirrors our own. Curious.
So wonderful to see that cooperative behavior! Funny little creatures 🙂
Don’t you just hate it when you’ve booked the removals, and the chain collapses at the last minute.