HCA: Hermit Crab Association

If new crabs have come from poor condition (most pet stores), isolation is extremely important. Many crabbers have been lucky to get some healthier crabs and they have survived without being initially ISO'd. But overall, the chances of getting a new crab to survive past the first molt (averaged for all crabs for all crab owners) is significantly increased by using a graduated isolation period. Remember the effects of environmental stress could take many months to manifest. Any crab is still a "new" crab until they survive their first molt. Transferring from a good tank to a good tank (for instance, adoptions, or from the ISO to the main tank) are not a major problem. Stress isn't as much caused by a change in surroundings (different tank, different toys, different bowls, different shelters, etc). So transferring a crab from an ISO to a main tank isn't a big deal. So there isn’t much need to worry about adding stress from this second move in a short period (pet store to ISO, then ISO to main tank), and that definitely is not a reason to skip isolation.The big shock that we usually associate with new tanks or deep cleans is caused by sterility shock. The substrate and water have a certain chemical and biological balance to them. If you completely replace it all with new/clean sterile substrate, that causes environmental shock to them. So just make sure your ISO is seeded with active substrate from the main tank.That's why I recommend saving some of the old substrate to mix in with the new. And save a bit of the old water when changing a large pool as well. I save about 1/6th to 1/4 of the old substrate, and about 1/2 cup of water. It has been documented in threads before that there seems to be an increase in deaths shortly following a full deep clean, and this is suspected to be the cause.Reference:Coenobita.org (Sue) wrote two articles on the importance of ISO and minimizing PPS: http://coenobita.org/xoops/mod...les/article.php?id=4 http://coenobita.org/xoops/mod...es/article.php?id=14 However, coenobita.org seems to be down for a couple weeks, not sure what happened to it. Around the same time Sue was working on those articles, I was experimenting with starting the ISO at lower humidity after a bout of healthy crabs dying from PPS. I wrote up the mini-caresheet on what I termed "Environmental Stress" and described my method of ISOing to minimize it. http://home.comcast.net/~jedim...PurchaseSyndrome.doc (Also linked in a sticky in the Zoea sub-forum. My document includes the coenobita.org links as reference). The methods look similar at first glance, but the details of what humidity to start at, how much to change, temperature changes, substrate depth, and ISO setup differ between the method I wrote up and the one that Sue describes. The best for you will be whatever works for you. My caresheet is really just a one-page description of my method of ISO. So definitely read the coenobita articles if you can find them, because those are multi-page descriptions of the "why" ISO is important and "why" PPS happens."Environmental Stress" and "Sterility Shock" are as far as I know my own terms and definitions. Other resources may differ in opinions.

The method of using a moist lower substrate and propping the lid by varying amounts that I describe in the document works pretty well for me at regulating the humidity +/-5%.Daily fluctions of +/-5% or even a little more aren't a big issue, just aim for an average at each graduation level.Keeping the cats out of the sandbox is the hardest part of maintaining an ISO after humidity in my opinion

Yesterday, I ended up going through all of my crab bookmarks to make sure they all still worked and came across this article on the one, regarding ISOing after purchase and why it is necessary... I found it quite interesting... it's a little long, but I found it worth the read and that along with JMT's information in this post has really got me thinking how I will ISO my newbies from now on to hopefully reduce the occurrence of PPShttp://naturallycrabby.com/?p=12

CathyGo, like I said in my post, you'll always find cases where crabs survived without ISO.What I'm talking about is on the average. It's about decreasing the chances of losing a crab to PPS. It's not about guarantees or absolutes.There will always be times when crabs survive without ISO, and there will always be times when crabs die even when ISOed.But on the average across all of crabland,deaths without ISO > deaths with ISO.But of course, current beliefs in crabland are always bound to change. Maybe someday in the future we'll find out that it's not humidity shock that causes PPS, maybe it's some other factor we didn't isolate yet. Until then you're free to experiment with whatever methods of adjusting new crabs you please, and the research we cummulatively create will benefit the next generation of care.I'm also careful about propping my lid due to the fact that they can scale the silicon edges and escape. What I do is make sure I don't prop it bigger than their shells so they can't get out the opening, and then I lay a heavy book ontop of it so that they can't "push" the lid up to get out more.