how well do hermits see?

[just jill]

Hi everyone!
I'm a newbie crab owner, I was volunteering at a Goodwill and
came across a aquarium someone had dropped off a couple of
days previous and looking through all the junk they had left in it
I saw a beautiful shell when I picked it up this creature burst out of it
and started to wiggle and pinched me. I dumped him back in the tank and started to watch him. Well you know how it went, I fell in love so I asked the manager if I could buy everything and she pretty much gav me everything for $20. She said she was just going to trash everything anyway. ( including Chuck!) I now have upgraded tanks twice and have now added 4 friends so he won't be lonely lol! They are the greatest creatures on earth! After looking all over the web I can't find the answer to my question.






I have to move my babies closer to the doorway and I want to know how well and how far they can see, I don't want it scare them every time I come into the room. Can anyone help me out?


started to watch h

[KellyCrabbieLove]

Mine seem to see well. Moving slowly helps but some are going to startle no matter what you do when you go even close to the tank. I have startled mine before accidentally and they have jumped back into their shells so quickly they have fallen off of things in the tank. It makes me laugh like crazy, maybe I am a mean hermit mom.

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[Crabinski]

Apparently amazingly well! My living room is 15' wide and 22' long and the guys can see me from at least 13 feet away (this simply stuns me). Their tank is against the far long wall of the living room and when I enter the room from either of the "short" ends, I see scuttling and/or hear that distinct "clunking" that accompanies startled bounces off tank walls. I can do the antenna finger wave thing from a good 8' away from the tank and have the crab watching come toward the front.

[Crabber85]

From everything I've read hermitcrabs don't really see that well sort of like horses their vision is very blurry due to the fact that their eyes are multifaceted like a flies eyes the image they are perceiving isn't being focused into one single image but is presented as multiple images which are out of focus, this means that they don't have great depth perception either which is why they will so readily crawl off the edge of a table because they technically can't see the edge until they've gone off it.

Its theorized that hermitcrabs can see movements better than making out any great detail because they need to know when a predatory bird maybe overhead in the wild the best way to tell is by shadow movement which is why they will quickly withdraw or scurry away when we approach because all they see is this sudden movement which they can only process as being a threat.

Hermitcrabs are also said to be much like reptiles in the respect that they can see into the ultraviolet light range which is why using black light emitting bulbs for nighttime heating confuses the crabs because all they see is the ultraviolet light it makes them think its day time all the time which can impact feeding, watering and with some species disrupts their molt patterns.

[wodesorel]

Casting shadows on them makes them panic more than them just seeing you moving around. They will calm down and not react as badly to movement over time, but they will always duck into their shells when there's a shadow.

Mine aren't very jumpy to movement and vibrations. I think it's because I have so many cats that it's become a normal part of life for them.

[KellyCrabbieLove]

Some are really brave. My buddy Thor never hides from me. Even if I were to jump at the tank he would just sit there and come to the glass. Maybe he is used to my kids running towards the tank when they hear noises or see movement. Megmaholm and I think he is just really stupid but maybe he is just really brave.

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[just jill]

Thanks everyone your answers really helped, I feel more comfortable moving my gang.