My crab will not stay in his shell

[CrabbyCakes]

1. What kind of substrate is used in your tank and how deep is it?
I use a 50/50 mis of play sand and coconut shell. It is 7' deep.
2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
I keep the take at 80 degrees with 80-90% humidity. I was keeping the humidity around 75 but they seem more active and happy with a higher humidity.
3. Is a heat source used in the tank? If so, what?
My tank is in a rook that is always 70 then I have three heat pads.

4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
I have fresh and salt water. I have a well so the water is pure on it's own. I use Zoo Med salt water conditioner to add the needed salt.

5. What kinds of food do you feed and how often is it replaced?
I give my guys fresh veg and fruit. I also give them dried shrimp and elive "variety bites."

6. How long have you had the crab and what species is it, if known?
This guy is a PP and I have had him for 2 years.

7. Has your crab molted, and how long ago did it happen?
He came up from his molt last week.
8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
I keep them in a tub with a plastic lid with holes.
9. How many crabs are in the tank and about how large are they?
I have five small crabs at the moment. He is the largest.

10. How many extra shells are usually kept in the tank, if any?
I have 22 extra shells at the moment.
11. Have there been any fumes or chemicals near the crabitat recently?
No.
12. How often do you clean the tank and how?
I do a deep clean about once a year and spot clean daily.
13. Are sponges used in the water dish? If so, how are they cleaned?
No.
14. Has anything new been added to your crabitat recently?
I put in a new climbing rope thing made out of grass while he was down for the molt.
15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?
I try to leave them alone (look do not touch) since they seem to get stressed out easily. I give them a bath from time to time.
16. Please describe the emergency situation in detail.
My one guy will not stay in his shell. He came up from a mold without a shell. I put him in iso and then he picked a shell. When he seemed fine I put him back in the take. Then again today he is out of his shell. I have him in iso again with a bunch of shell options.

[CrabbyCakes]

Update. He has picked a shell.I am going to keep him in iso. I am worried as soon as I put him back in the cage he will just drop the shell again! I have never seen anything like this!

[AutumnHermie]

The best thing you can do right now is to keep him in ISO as well as offer him foods like cuttlebone, honey, and PB. One thing about your care; Zoo Med saltwater conditioner does not offer all of the minerals found in the wild, instant ocean is what most people use/prefer.

[DragonsFly]

This is eerily familiar; it just happened with one of my crabs (a little over two months ago). He came up from a molt without a shell, then repeatedly refused shells. I'm very sorry to say that my crab eventually did not make it (our first crab death ever, in over 5 years ). HOWEVER, if yours IS keeping a shell on in iso, then yes, keep him in iso and see if the crisis passes. It may be that something went wrong in the molts, resulting in some kind of disfigurement or disorder that causes them to reject shells? I have no idea. In my case, I also think shell aggression and competition for the few shells I have with a rare opening size (openings between 1 1/16, 1 1/8, 1 3/16 inches) may have played a role. While he is in iso, as undisturbed as possible, check the shells you have in the main tank with calipers and see if you might have a shell-opening-size gap, too.

[CrabbyCakes]

The best thing you can do right now is to keep him in ISO as well as offer him foods like cuttlebone, honey, and PB. One thing about your care; Zoo Med saltwater conditioner does not offer all of the minerals found in the wild, instant ocean is what most people use/prefer.

Good to know! I will switch brands. Thank you for your help.

[CrabbyCakes]

This is eerily familiar; it just happened with one of my crabs (a little over two months ago). He came up from a molt without a shell, then repeatedly refused shells. I'm very sorry to say that my crab eventually did not make it (our first crab death ever, in over 5 years ). HOWEVER, if yours IS keeping a shell on in iso, then yes, keep him in iso and see if the crisis passes. It may be that something went wrong in the molts, resulting in some kind of disfigurement or disorder that causes them to reject shells? I have no idea. In my case, I also think shell aggression and competition for the few shells I have with a rare opening size (openings between 1 1/16, 1 1/8, 1 3/16 inches) may have played a role. While he is in iso, as undisturbed as possible, check the shells you have in the main tank with calipers and see if you might have a shell-opening-size gap, too.

That is my worry. He keeps on switching then deciding he just wants to be naked. You are right. I will measure all of them and see if I can find something else he likes. Do you know if this happens in the wild?

[DragonsFly]

No. It could not happen in the wild, because a naked crab on the surface would be snatched up by a hungry bird--"Look! A land shrimp!" and that would be the end of it.

This is something about captivity. You can look at my thread about what happened with mine, I really tried to explore all possible avenues--shell being stuck underground, shell aggression (that did seem to be involved), too hot in the tank, all kinds of things. The fact is that we are trying to provide for these animals without truly knowing everything they need, even in nature--which we could never provide even if we knew what it was, in captivity. So it's a constant learning process, and unfortunately, sometimes these weird things are going to happen. It is important to make sure we have the best conditions possible according to what IS known, and after that, if we can try to figure out what MIGHT be going wrong in this case, maybe we can add to the knowledge base, but honestly, from all I've read here over the years, sometimes they just seem like they've had enough and they're "checking out."

Maybe it's a chronic low-level nutritional deficiency, maybe lack of UV light, maybe lack of exercise, maybe bacteria or viruses we are unaware of that attack because their immune systems get weak in captivity from one of these factors or something else we don't even imagine is important. Maybe it's a mineral deficiency, since no matter what we do we can't truly replicate natural minerals in natural water sources and the environment. Maybe it's all of these things--and more--adding up over time. Maybe they just miss freedom--the ocean, the sea breeze, and the ability to interact with a complex environment--climb actual trees, eat real decaying food, dig as deep as they want to, actually mate and reproduce--we really can't know.

Best wishes, I REALLY hope your story has a more hopeful ending than my recent one did. Rooting for you.

[mool]

Sometimes stressed/weak crabs will stay shelled if the shell is very light weight. I would recommend finding the lightest weight shells of the correct size (and type, if possible) and put those into iso with him.

[DragonsFly]

Yes, good idea-- if you have any fully polished turbos of the correct OPENING size (around what he is wearing now--remember that size of the overall shell does NOT directly correlate with size of the opening), let him have those as options, too. Polishing makes them lighter--the "pearled" ones have been polished all the way down to the inner layer, so they are the lightest relative to opening size.

[soilentgringa]

Unfortunately when a crab repeatedly ditches their shell, they are either too weak or ill to carry it. They often drag themselves to the salt water dishes in these cases and pass soon after.
If you can get the crab to stay in a shell there may be some hope. Rinsing the shell and crab gently and guiding the crabs abdomen into the shell and gently tapping it's head behind the eyes to make it pull itself in the shell and then ISO'ng in good conditions is what we usually suggest in these cases. If it stays in the shell, leave it alone. Don't handle it or fuss over it. It's a waiting game after that.
I'm sorry I don't have more positive news for you

[CrabbyCakes]

Maybe it's a chronic low-level nutritional deficiency, maybe lack of UV light, maybe lack of exercise, maybe bacteria or viruses we are unaware of that attack because their immune systems get weak in captivity from one of these factors or something else we don't even imagine is important.

I had not thought about the light. Do you have a special bulb you put on your tank?

[CrabbyCakes]

Sometimes stressed/weak crabs will stay shelled if the shell is very light weight. I would recommend finding the lightest weight shells of the correct size (and type, if possible) and put those into iso with him.

Thank you for the great suggestion. I never even though of that. I wish he would take a snail shell since they are so light, but he really dislikes them. I am on the hunt now!

[CrabbyCakes]

Unfortunately when a crab repeatedly ditches their shell, they are either too weak or ill to carry it. They often drag themselves to the salt water dishes in these cases and pass soon after.
If you can get the crab to stay in a shell there may be some hope. Rinsing the shell and crab gently and guiding the crabs abdomen into the shell and gently tapping it's head behind the eyes to make it pull itself in the shell and then ISO'ng in good conditions is what we usually suggest in these cases. If it stays in the shell, leave it alone. Don't handle it or fuss over it. It's a waiting game after that.
I'm sorry I don't have more positive news for you

He has been dragging himself to the salt water (shell-less.) Man. Hopefully he will stay in his shell. It is good to know I need to prepare for the worst. I am far too attached to my little guys.

[CrabbyCakes]

UPDATE My little guy is eating and is in his shell!

[mool]

That is good news! Be sure that your food offerings include organic honey and peanut butter. Those are the best two foods for extremely stressed crabs.