HCA: Hermit Crab Association

This is a morbid subject, but one I've been thinking about a lot lately, and I just wanted to get others thoughts to see if I was offbase or on track.

I was thinking about cause of HC deaths, in order of most common, to least common. It might be helpful in research and combating these problems if we identified which problems were most common.

PPS-I feel pretty strong this is number one

Stress from improper conditions after PPS-this mainly referring to improper humidity and temp issues, nutritional deficiencies or bacterial breathing issues (chemical poisoning from unclean tat), this being displayed by any stressed behavior like losing limbs or possibly naked crabs, could even refer to the deaths from agression due to overcrouding

Crab Aggression-it seems like a pretty common cause of death in my mind, this could mean cannibalism, although there is another kind of cannibalism I would categorize under molting issues, but the more common forms of aggression like shell fights and dominance displays

Illness/Infection-those crabs who spend tons of time soaking in the salt water for reasons unknown, die mysteriously a month or less after molting (soft molting bodies are very prone to infection and the bottoms of the tat where they molt have the most bacteria), swollen abdomens, black spots or puss, all those kinds of issues, keeping in mind crabs really aren't prone to disease, and don't get infections unless having an open wound or those soft molting bodies

Molting issues-anything from a molt deformity resulting in death, to a caved in tunnel, to cannibalism

Miscellaneous other- old age(I wish), drowning seems uncommon but happens, falls, depression, or those deaths which really and truly are mysterious and could be genetic, or based on some other factor we don't understand

Have I missed anything obvious? Do you feel they are in the wrong order? Am I totally morbid?

I totally agree about the first two. When I was first reading your post I was thinking definitely PPS and next would be temp and humidity problems. I don't know enough about the rest of the issues to rate the others.

I got a little freaked out about the bacteria on the bottom of the tank, I didn't realize that that was an issue. Five of my nine are buried now and I can't help but imagine them wallowing in yuck . I can't really see their poops that well, which makes me nervous that my tank is filled with bacteria. Every once in a while I find a big stash and scoop it.
Okay, I've gotten off track here...

Anyway, I like that you are doing this crabber, I think you are right, it could be helpful to have a list of the most common death causes so people can learn to avoid them.

I didn't mean to freak anyone out, but honestly it freaks me out a little bit.

I was researching about the bacteria in our tats when I lost my straw a month after a molt, and was convinced it was due to an infection she got while molting. Some of her exo had some nasties on it when I examined it later. Crabs are just so vulnerable when their exo is hardening, I've done reading on that too, the molting process takes a lot out of them and leaves them more susceptible to infection than I think we realize.

I also noticed while doing my last deep clean that the sand at the bottom of the tank was still very damp, which surprised me because the top was starting to get dry. In my research I uncovered that this is because the water slowly seeps down to the bottom, and gets stagnant and this is where the worst bacteria forms, which I used to think the worst bacteria was at the top layer, where waste and food was.

I was reading about vivarium habitats, and basically the idea is to create levels of substrate which increase the good bacteria and keep the bad away from the crabs while molting. I'm going to do this at my next deep clean, although it has some disadvantages.

You'd layer the bottom of the tat with an inch or so of gravel, as we all know crabs can't dig into gravel, so it keeps the worse of that stagnant water and the bad bacteria away from them while molting. Then I'll do a layer of EE to help breakdown bacteria, and the top layer will be the sand I'll clean and replace with the most frequency.

The disadvantage is that adding the gravel adds major time and pain in the deep cleaning process! But for me I feel like the peace of mind I'll get from a vivarium crabitat will be worth it, plus it will allow me to do deep cleanings a little less often as well. I feel like the bigger the tat the more someone may want to consider doing a vivarium tat so they'll have to deep clean those massive tat less often with less worry.

Wish I had read this before I set up my new tat! Good info to know about the vivarian crabitat setup technique.

Thanks. I'm excited to do my next deep clean and change it to a vivarium tat, I have 5 down now, two of them mediums who will be at least a month. I can't wait until they come back up!!! I'm not a germaphobe or anything, but I've read multiple articles on bacteria in a crabitat, and I feel like it's like the nutrition and nutrients issue, it's something we have don't figured out completely yet, more room that I can improve. Or at the very least worry less, and jeeze, peace of mind is worth a lot to me.

Maybe add some kind of handler mistakes... I dug up a molter... he died shortly after.

Did you see the post about EE? If the package doesn't say 100% coco fiber then it has other stuff in it and it's not good for the hermits. I don't remember the specifics but can try to find it if you haven't seen it.

Thanks for the reminder about the EE. Yes, I did see it. EE that creates bacteria is the last thing I want in the tat! I already exchanged it for FB. This will be my first time using a coconut fiber and I hope all goes well.

You are correct, I did not add handler mistakes. I'm thinking that would fit best under Miscellaneous other. I think I remember your sad post about the dug up molter. You should still consider the fact he might have been weak and not have made it anyway, since many of us have dug up molters (myself included) and they were fine afterwords. I feel for you on that one, that's a painful loss, but still it's very possible not at all your fault.

Crabber, I think that you have a good list going there. It's good for owners to realize all of the different causes instead of blaming themselves right away. Good job!

oh wow, i really like this info, i might print it off.

hmm, i am due for a deep clean soon, i will go buy some gravel and crabbing soil!!!!!! (already have sand)

I would probably say that after PPS would be molting problems, or maybe molting problems could even be lumped together with PPS. I have often wondered if LHCs have such molting problems in the wild as well. Most crabs that I have lost have been due to molting. It would seem unlikely that so many would die due to molts in the wild. I have definitely had the most fatal problems with molts though.

hey, i was thinking: is it possible to add some plastic wrap between the gravel and soil with like, holes punched in it for air flow? Or would this make the bacteria grow worse?

That would probably catch another layer of stagnant water

It would reduce the gravel's ability to perform its drainage function.

yeah...true, that makes sense. thank you.

I had two crabs die when my substrate got over saturated... I just added a new pool... the crabs kept moving the substrate up near it and it was wicking out... I didn't realize it until it was too late... and I kept filling the water dishes. They were both burried... I don't know why they didn't just come up.

Wow, crabber. That's fricking great. And your idea about a vivarium set up is extremely good. I think I'll have to try that. Thanks!