Crab constantly in corner near heater bulb

[NeatHedgehog]

1. Coco fiber and sand substrate, 6-8 inches.

2. Digital Zoo Med Hygrotherm, cross-checked with a Zoo Med humidity gauge which was calibrated with the salt test. Humidity reads 80-85% (floor value is 81%) temperature is 80-82 in the hottest corner by the heat bulb where he sits, 78 at the digital sensor (mid tank), and 77 in the coldest corner. All temps double checked against verified mercury thermometers.

3. 100w ceramic heat bulb from above.

4. Fresh and salt water, treated with API heavy metal neutralizer (well water supply, no chlorine). Salt water is mixed to 1.025.

5. Food is replaced once a day, or once every other day depending on looks. Green beans, grapes, egg, shrimp, meal worms, apple, honey-sweetened oats (sparingly), celery, pork, cuttlebone is always available both crushed and whole.

6. Just under two weeks. Should be a "Purple Pincher."

7. No known molts.

8. 30g aquarium. Lid is solid plywood sealed with multiple coatings of plasti-dip. There are two openings, one for the heat lamp and one for a UVB bulb (Repti-glo 5.0) which has a screen to reduce the intensity of the light.

9. 6 crabs, all teeny to small.

10. About 15 extra shells.

11. No fumes or chemicals are allowed near the tank.

12. Glass is wiped down once a day or every other day with a "magic eraser" wetted with the same treated water they use for drinking / bathing. Have not done major cleanings on the substrate yet (tank has been in operation for three weeks, two weeks with crabs).

13. No sponges.

14. Extra coco fiber was added after substrate "settled" too close to 6 inches.

15. The flow rate of the misting system was reduced after 2-3mm of flooding was discovered under the misting nozzles when I dug a hole all the way down (took about a minute for the water to seep in and level off). Roughly 50% of the total substrate was turned over (didn't disturb any diggers, somehow), dried, and I used moss and coco-fiber to soak up excess water. No dark spots, no bad smells. Center tank area was not flooded. The bottom half inch was overly moist, the rest was sand-castle consistency. He was already lethargic several days before I did this, and had made no attempts to dig in this.

16. This particular crab came with a shell that was too small for him to fit, and it was full of holes. While the other crabs were active, he stuck himself in a crevice and hid. He changed shells after four days, but remains mostly inactive and stays in the corner below the heater. He ate a little honeyed oats I put together for him on Friday, but not sure of anything since. I put boxes in front of the tank so he doesn't get spooked by me walking around. I see him shift a leg now and then, but not much else. Basically hasn't moved more than a couple inches in nearly a week. He did spend an inordinate amount of time on the edge of the water dish prior to when he mostly quit moving, though.

I dug about six inches from him while I was replacing and checking substrate conditions because of the overzealous misting, and it's not flooded over there. It would seem to be a swell spot to dig, but he doesn't. I am concerned that he is messed up from living in such a rotten shell and likely being unable to molt. Should I just leave him there and try to "wall off" the area so the other crabs don't bother him if he's trying to surface-molt, dig a hole and see if he moves in (possibly he is too weak to do it himself), or move him to an iso tank? I don't want to stress him out more by trying to help too much. I've been leaving him and everyone alone aside from what I did to the substrate because I believed that was going to become an emergency in itself if I didn't resolve it.

For comparison's sake, everyone else I brought home with him appears to be doing well, all but one have swapped shells, and most of them are beginning to be active during morning / evening times instead of just dark night.

[CallaLily]

It is possible he's preparing to molt and will hopefully dig down soon. Post Purchase Syndrome is another possibility. I don't notice anything off with your set up and it sounds like you caught and handled the flooding well.

[NeatHedgehog]

Yeah, I am hoping it's molting behavior, although PPS after the rough time he seems to have had wouldn't surprise me either. It was the standing around in an open spot instead of hiding that was bothering me; if he'd kept hiding that would make more sense to me.

Guess there's not much I can do until he tips his hand / claw, except keep the others away. They don't seem interested in him at the moment, fortunately.

It just makes me paranoid; I am usually the guy who tries to fix things that look wrong (although not doing anything can be the fix sometimes, because nothing is actually "wrong").

[thermidor]

I have a couple of crabs that have a very determined preference for one spot; almost as if it is THEIR spot and I have actually seem them shove someone else out of their spot, only to sit there and do nothing. In other words, not guarding a food source or a fabulous hiding spot, just a spot.

[NeatHedgehog]

I dug a short tunnel with index and middle finger last night a ways off from him to see if he'd take interest. This morning I see he has indeed climbed in and is making himself at home, so I might as least not have to be too concerned about protecting him.

[CallaLily]

Awesome! Hopefully he'll dig further. You could also carefully place a hide over him and the tunnel for further protection. Please let us know how he does.

[NeatHedgehog]

Well, he is out to make me look silly, I guess. :roll: Heard a scraping noise over in the corner and he had popped out of his hole to splash in the fresh water. After all that time of sitting like a bump, he has been climbing / standing around on a stubby lava rock, standing up in his corner spot, and being surprisingly tolerant of me peering at him the whole time. He still favors the hot-spot, but he is at least not as weak as I feared he might be.

A terrible quality pic by the water dish, standing over an empty shell. It is shadowy over there so I had to do gamma / saturation correction to make him visible because I didn't want to use the flash.

[NeatHedgehog]

RIP Unknown Crab. He tried to dig down a few days ago in the hole I made, but was too weak to deepen it. I covered him a bit so he would be safe, and there was no sign of attack, but nearly all his legs came off in the hole when I checked today due to bad fish smell.

Wish I'd had a chance to get to know you better, little guy.

[CallaLily]

I'm so sorry to hear he passed.

[Tarn]

I am really sorry to hear about your crabbie