Musical Shells

[catsittingstill]

Cassiodorus, the bigger of our two hermit crabs, swapped shells last night. He's been interested in other shells for some time, but most of the spare shells Kip and I had gotten for the crabs were too big (it's hard for a human to judge these things and we always erred on the side of too large). One shell met with enough approval that he swapped into it when we first got the crabs, but he hastily swapped back again.

This time Julian, the smaller of the two crabs, noticed what he was doing. She came over to investigate, and though he shoved her away from his old shell, he was also hurriedly trying out his new one, and while he was practicing to see if he could pull all his limbs inside the new one, she snuck around behind his back and quickly swapped into his old shell, leaving her old one behind in its place. She seemed to have no doubts about her new shell, hurrying away again after only the briefest session of feeler-patting and groping to see how big it was on the outside.

In the meantime, Cassiodorus is not completely happy with his new shell. He even swapped out into Julian's old one--but it was so small he couldn't even pull in far enough to get his eyestalks under cover. Kip and I watched this for a while, engaging in the human habit of empathizing with something that probably feels no emotion whatsover, and finally couldn't stand it anymore. When Cassiodorus swapped back into the large shell we took Julian's old shell away from him so he would quit agonizing over it.

The next time we go into Knoxville we'll take Julian's old shell with us so we can pick out a couple that are just a bit bigger and give Cassidodorus more choices.

Comments

[hobbitblue.livejournal.com]

I didn't realise people kept hermit crabs.. that all sounds fascinating, especially going and getting them new shells to play with and try out!

[catsittingstill.livejournal.com]

We found ours for sale at a mall in Knoxville. They aren't as rare as you might think--once we had a couple, we spotted them for sale in other pet stores too. The book (of course we got a book :-) says that they like having new shells around to play with and try on. I just feel kind of guilty that we don't have another shell the right size :-/ It's really fascinating to watch them switch shells--Kip and I must have stood by the tank for half an hour watching our own mini Wild-Kingdom drama.

[hobbitblue.livejournal.com]

Fascinating, I'd watch for hours too, though I'm a bit edgy about crabs, I'm scared of spiders cos of the leg thing, and crabs have the same sort of vibe at times...

[randwolf.livejournal.com]

Gee, was Cassiodorus experiencing shell-o-sy?

[catsittingstill.livejournal.com]

(snicker) shell-envy, perhaps.

If I have time I may even go in to Knoxville today and see if I can find a couple of shells closer to the right size.

[musicmutt.livejournal.com]

Are they terrestrial hermit crabs or aquatic? You know, I wouldn't be so quick to jump to the conclusion they feel no emotion. I think emotion is probably a fundamental element that drives behavior. They may not experience complex feelings or anything, but I think there's a lot more to behavior than strictly stimulus-response.0

[catsittingstill.livejournal.com]

They are terrestrial hermit crabs. We keep them in a 10-gallon aquarium with sand for them to dig in, and a big dish of water to help keep things humid because even terrestrial crabs need to keep damp.

I agree with you in general about more complex animals experiencing emotion. I have my doubts about hermit crabs because 1) I think we're talking about a brain the size of a pinhead and 2) most of the time my automatic human estimates of what they will do next based on what emotions I think they feel (based on their body language and immediate circumstances) are just way off. They never do what I expect. Thus my hypothesis that they don't experince emotion in the same way that humans do.

Cassiodorus still looks like he's sulking, crouched facing into the corner of the tank. But maybe he's only resting up to get the energy to look for a better shell.

[randwolf.livejournal.com]

They aren't mammals; most human intuitions about emotion are based on mammalian cues. Being warm-blooded creatures has a lot to do with the basics of mammalian emotions, which makes for a huge between humans and most species. To know if crabs experience emotion, we'd have to first have a species-independent definition of emotion, and we don't. This is a question from the big box of philosophical questions traditionally labeled "nature of the soul" (or, for philosophical materialists, "mind") and there's not much reliable knowledge there.

[musicmutt.livejournal.com]

Well, no, I don't believe they experience emotion the way we do, and they certainly wouldn't analyze them the way we do they just react. But I do believe that any animal with a CNS does feel emotion at some level because it is rather necessary for surviv al. Fear elicits fight or flight reactions. Aggression is important for gaining and maintaining mating rights. Comfort brings about happiness, as will happen with Cassiodorus when he finds the right shell. We continue to be surpised by critters and realize we've been underestimating them. Brain size and complexity may mean less than we think. Ants have shown abilities to reason and solve problems and learn from mistakes. I'm not saying they'll be going to the moon anytime soon, but there may be more going on in those tiny little brains than we give them credit for.Ö