Crabicide or accidental death?

[Slowbro]

URGENT!
I have been crabbing for over a year now and I haven't had any deaths in the past but 2 of my hermit crabs have died in the last month! I found Vaporeon naked in the corner a few weeks ago and just this morning I found Glaceon dead too! Can someone help give me reason for their deaths?
I have a 10 gallon tank and have (had) 7 hermit crabs. For bedding I have been using desert sand with a bit of gravel, shell grit and oyster shells mixed into it. I feed them HBH crab cakes and cookies with some occasional fruit and the temperature in the tank looks okay.
Have I been doing anything wrong? Is it possible that Jolteon is a serial killer because I saw him push the others around recently? Or maybe was it because I added the shell grit and oyster shells to make my tank have a more natural look?
Please help, I don't want my other hermit crabs to die too...

[ladybug15057]

I am so sorry to hear of your losses. This can certainly be heart breaking for a hermie parent. But we do need more information so please answer:

What is the volume of your main tank?


How many hermit crabs do you currently have? How big are they?


How long have you had the hermit crab(s) that you are concerned about?


What substrate or combination of substrates are you using? How deep is it?


What do you feed your hermit crabs?


Do you use distilled, bottled or tap water? If you are using a dechlorinator, what brand is it? Does it state to remove all heavy metals, chlorine and chloramines?


What brand of sea salt are you using to supply your hermit crabs with salt water?


What heat source are you using and where is it positioned?


Have you calibrated your thermometer(s) and hygrometer?


What is the air temperature range and humidity inside the tank? If you are using an under tank heater, what is the temperature range of the substrate (it is likely to be different to the air temperature range)?


Do you have any photos of your tank or hermit crab(s) of concern? If yes, please attach them to your post.

With the shell grit and oyster shells there is a high possibility that a piece may of gotten lodged within their shells, or even punctured their soft abdomen. The desert sand is usually a powder type in consistency and possibly could of clogged their gills too. The cookies you feed contain ethoxyquin (insecticide) and should not be offered. Fresh foods and one from the hermie food pyramid should be offered daily. Please do answer the questions above so we can help you more.
There are occasions too however where a hermie who is in premolt has been known to get a little crabby too and should be iso'ed from the others.

[Wai]

There was another crabber recently who also had oyster shell chips in her bedding. Check out her thread for some further reading.
viewtopic.php?f=91&t=3603

The oyster shell chips are a potentially deadly hazard, so I would sift through the sand (or get new sand, as Marie suggested) to get rid of them. Likewise, the gravel could also slip into shells and puncture abdomens.

If Jolteon continues pushing the others around, I would isolate him for a few days in case he would like some time on his own. Is he much bigger than the others?

[Slowbro]

Well... I have a 10 gallon tank, 6 small hermit crabs, with Jolteon being slightly bigger. I have had them since 29th May 2009. I use tap water with a dechlorinator, API brand. HBH salt. I use an aquarium hood light for the heat source and he temperature is usually about 74'F. Does that give any clues? I asked a friend and he told me I might be the oyster shells, but the store I bought it from told me it was fine.

[ladybug15057]

The oyster shells can get within the hermies shell and puncture their soft abdomen. 2 things hermies do not regenerate when molting are their gills and their soft curly abdomen so any damage done to either of these are permanent, harmful, and eventually lethal.
The HBH salt is worthless. Please do read: (It is long but well worth reading)
http://crabstreetjournal.com/xoops/modu ... storyid=20

Please do take what employees at pet stores tell you with a grain of salt.

[Wai]

Instead of oyster shells and shell grit, you can offer a piece cuttlebone instead (sold in the birds section) since it is too big to slip into their shells.

[Suebee]

My substrate is 5 parts sand to one part EE with oyster shell mixed in moistened to sand castle wetness with sea salt water. Its also what The Hermit crab patch and Exotic land Hermit crabs suggests. http://www.hermitcrabpatch.com/Hermit-C ... /sb030.htm
I often see my molters through a little window munching on crushed oyster shell getting the needed calcium they require. They have natural bits of oyster and clam shell in the natural inviorment, however not to much gravel. Gravel can be sharp, if you feel crushed oyster shell the pieces are more rounded and dusty.
Gravel mixed in could be the problem.
HbH salt can also be fine as long at its mixed properly http://www.hermitcrabpatch.com/Hermit-C ... /wr001.htm I use oceanic salt due to more mineral content however I trust anything the researchers at HCP trust.
If the substrate is all that has changed I would think that is a good place to start with answers.

Crabs will ditch the shell if the shell is broken on the inside, a collapsed turbo can cut the body and make the crab go without a shell looking for a pool to soak in. Another reason could be humidity , they need to be able to keep water in the shell without drying out. Sometimes a crab that gets to hot due to a light directly on the shell will also ditch the shell.
I would make sure you have a good shell selection for the type of crabs you have too. Hope all goes well and no more deaths happen..
You may want to look into a bigger tank with that many crabs also.
Just a reminder your substrate should be deep enough for your biggest crab to molt. As a rule of thumb i usually sugest that for a one inch high crab you have at least two times deeper substrate so you would need at least at least 3 inches of substrate 4 or 5 would be much better.

[CrabbyJo]

Unfortunately HBH salt has been researched and found to be unsuitable for hermit crabs. A quote from an article written by one researcher:

HBH Hermit crab sea salt Ingredients: sodium chloride, magnesium chloride, calcium chloride, potassium chloride, potassium iodide
It contains the wrong form of calcium and it contains normal table salt ingredients sodium chloride/ potassium iodide. HBH salt mix also contains a highly corrosive magnesium chloride that is used to stabilize the iodine. (Thanks to SUE, RFCrabs for this information regarding HBH salt mix)

You can see the article in it's entirety at: http://crabstreetjournal.com/xoops/modu ... storyid=20

It is well known that ocean salt mixes meant for salt water aquariums are highly superior to salt water mixes made for hermit crabs, as they contain more of the essential nutrients needed for good health.

74*F is a smidge on the low side temperature wise, if it stays there consistently. It would be a good idea to make sure they have a warmer side they can move to so they can moderate their body temperature, say about 80*F.

[Suebee]

Researches and Researchers Compaired.. I stick by HCP and ELHC. I would say that it isnt the best salt for long term, however It wont kill your crabs and if it all you are able to come by like some, Id use it. I dont like to use other boards as research. This is my opinion. If you have more questions I know HCP will answer any questions regarding the salt or any products that they sell. In my opinion they are the best and I fully have trusted them for the many years of research, not just owning crabs..

As for the crab street journal, If I were up to actually going to that site I could show you pages of missinformation. I learned the hard way. My opinion based on past things said and people attacked by that site is to stay far away from there.

[emmac350]

If there is no difference between HBH and ocean salt waters, then why did my adopted crabs who were given the HBH salt for over a year act like they'd never had salt water when I first gave them ocean salt water? These crabs were extraordinarily stressed from 4 hours of driving but literally ran to the bowl of ocean water and jumped into it and drained the bowl every day for two weeks following my adopting them. There is a difference between the salts - namely that they don't contain all of the elements that crabs need out of salt water. If they aren't offered an ocean salt, crabs will recycle their urine into their shell water to maintain the proper level of salinity/dissolved solids to keep their abdomens from turning pruny (like your fingers do when you're in a pool for too long) and them actually absorbing so much water into their abdomens that they can get sick or die from it (due to osmosis).