Crabs Dying And Can't Determine Cause

[Sorakachan]

Recently, I moved back into my home for the summer, got a new, bigger terrarium than before, got better substrate (I combined jungle bedding, the gravel, the calci-sand, and crushed up oyster shell and made sure it was moisturized well), got more stuff for them to climb on, got more bowls and got rid of the sponges, added moss and mixed it in with the substrate, and I keep a reptile night light on for them that simulates the moon at night. I recently started turning on the day lightbulb as well just to see if it helps with my predicament.

Basically, before I moved here and changed all those things I had a large critter tank (whatever ya call them) and the same type of substrate without the moss. I had a bowl for freshwater and a bowl for saltwater (I now also have a bowl for food instead of using a shell). I was in my college dorm then. At the point at the end of the school year, I had ten living hermit crabs.

I have had twelve in all. Two died during my months at college (First crabs bought in early March, last month of school was early May). When I get home (I've only been here about three weeks), I get all this stuff set up and even buy new shells for them as well so they have more to choose from. I thoroughly cleaned everything before putting it in the terrarium and I thoroughly cleaned the terrarium before as well (all with hermit-safe stuff and methods).

However, suddenly, I've lost three crabs since coming home. One of which was extremely dear to me. He was my largest one. I also lost a medium one and a very small one (which had just recently finished a molting, so I thought she was doing very okay having survived that well). There are no bug infections in the tank and each time one died, I thoroughly cleaned the tank and everywhere the crab was in it's last moments. I certainly hope that would prevent spread of disease if that's the cause.

Why are these crabs dying so quickly? I don't know what could be wrong. The only explanations I've thought up thus far is possibly getting less sunlight (hence use of the daylight bulb recently) or the overall move from my dorm and a smaller tank to my house and a larger tank. Can anyone else think of any other causes and how to possibly prevent future crab deaths? I really love my hermies!

[Wai]

Welcome to Hermit Crab Paradise! There are many things you haven't mentioned, so please answer the questions below so we can see what could have gone wrong.

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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.

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I am guessing that you weren't aware of the importance of high humidity in their tank? Also, you should not have any gravel, calci-sand or crushed oyster shell in the bedding as they may scratch the soft bodies of moulters (calci-sand can become jagged when hardened). Have you been feeding them commercial hermit crab food such as those by ZooMed, HBH etc? If yes, throw them out as they contain preservatives that cause long term harm to hermit crabs. Same goes for "hermit crab salt" products. You need sea salt that is approved for salt water fish, such as Instant Ocean or Red Sea Salt.

From what you have told me so far, I assume you haven't read through the Crab Care section. Even though it will take a while to read, it contains valuable information and it will take you less time to read through it than to wait for replies from us.

[Foxydiva3]

Hello there, Def Answer those Questions Wai provided, I will say this that it is much harder to keep temps and Humidity correct in a larger tank. You mentioned before that you had them i like a small critter thing. So it may be as simple as finding the proper ways to get your tank regulated. Do you have a Glass top on your tank? That Helps me be able to keep stable temps and humidity, Good Luck and I Hope all works out for you.
C

[ladybug15057]

I know the questions Wai posted are detailed, but extremely important to answer. I know you have also asked this on Yahoo Answers and I do highly recommend to take into serious consideration what is answered here as opposed on Yahoo answers. I was going to reply there later today, but since you joined HCP and asked here this is better.

[Sorakachan]

I know the questions Wai posted are detailed, but extremely important to answer. I know you have also asked this on Yahoo Answers and I do highly recommend to take into serious consideration what is answered here as opposed on Yahoo answers. I was going to reply there later today, but since you joined HCP and asked here this is better.

Yeah, when I looked on Yahoo answers and all I was getting were questions asking if I watched the humidity of the tank, I wanted to hit my head against something. I'm talking about substrate and molting and such and they think I don't know that I need to measure humidity? (sigh)

[Sorakachan]

What is the volume of your main tank?

10.4 gallons. Once I can find one for a good deal, I plan to upgrade to a 20 gallon at the least (that's the largest allowed in my dorms at the moment. Once I move into an apartment, I plan to get a much larger one).

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

7. I have two very small ones, one inbetween-small-and-medium one, and four medium crabs. Of course, this is all by Earthbound's measurement standards, so they may not be exactly the sizes most crabbers may consider as medium or such. My largest one's leg span is about 2.25 inches.

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

They all have varying times I've had them. The one I've had longest is one of the small ones. I've had her since early March. The rest I've had a little over a month, for the most part.

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

I used to use jungle bedding, a small amount of gravel, a small amount of calci-sand, some moss, and a small amount of crushed oyster shell all mixed together. However, because of your advice below, I have changed it to a combination of jungle bedding, moss, and coconut fibers. I always keep atleast three inches in my tank, sometimes more.

What do you feed your hermit crabs?

I used to feed them a combination of many different hermit foods, including, but not limited to, two types of pre-made hermit crab foods (these had preservatives), crushed egg shells, freeze-dried fruit, freeze-dried vegetables, dried leaves, and some calcium supplements.

Since I had mixed those all together before, I had to get rid of even the good things. I recently changed it to crushed egg shells, dried shrimp, a calcium block (I looked at the ingredients and it seemed to have no preservatives, getting the powdered calcium was too much on my budget at the moment), dried papaya, dried raisins, and rose hips. I have mealworms but they could mold and such, so I'm saving them for when I can keep a good watch on the food and have a separate bowl to put just those in.

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?

I use distilled water. Whenever I clean things, I use tap water with a dechlorinator and stress coat, the brand is API.

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

I originally used HBH hermit crab salt, but because of your advice and looking through the crab care section in that area, I recently got Oceanic natural sea salt mix

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

I am only using a light right now because our house is very hot at the moment. We do not have an AC on this side of the house, so the terrarium has stayed within the temperature range according to my thermometer within the terrarium. During the colder seasons, I also put a heating pad underneath the terrarium.

Have you calibrated your thermometer(s) and hygrometer?

I use a Zoo Med combination thermometer/hygrometer. How do I go about calibrating this?

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)?

I always stay within the range specified on my thermometer/hydrometer for hermit crabs. Right now, the temperature is 79 and the humidity is 72.

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

Sadly, not yet. I plan to take pictures once I have time, but I've been so busy lately!

[Wai]

Sorry for the late reply, but I'm guessing your hermit crabs may have died from preservatives in the 'hermit crab food' or the crushed oyster shells in the bedding. One of Marie's hermit crabs died after a piece of oyster shell from the food dish slipped into its shell and punctured its abdomen. Being surrounded by oyster shell pieces in the bedding, there is an even greater risk of the pieces slipping in their shells or scratching their bodies after a moult.

Also, don't forget to feed them some meat. Raw or slightly cooked is fine.

Gauge calibration instructions are on the Calibration page.

[ladybug15057]

Yes, King crab did have a puncture in her abdomen due to a piece of oyster shell getting lodged in her shell from the food dish. This can also happen from a stick found in the eco earth too.

[ladybug15057]

What is the volume of your main tank?

10.4 gallons. Once I can find one for a good deal, I plan to upgrade to a 20 gallon at the least (that's the largest allowed in my dorms at the moment. Once I move into an apartment, I plan to get a much larger one).

Have you considered looking on free cycle? Some crabbers have found larger tanks for free from those who are spring cleaning. Another good place to find items less expensive is Craigs list, or even yard sales.

How many hermit crabs do you currently have? How big are they?
7. I have two very small ones, one inbetween-small-and-medium one, and four medium crabs. Of course, this is all by Earthbound's measurement standards, so they may not be exactly the sizes most crabbers may consider as medium or such. My largest one's leg span is about 2.25 inches.

This does sound like you may have a little aggressive behavior going on due to over crowded conditions too. For now, are you able to attempt to make a second level to increase some of the space in your tank?

How long have you had the hermit crab(s) that you are concerned about?
They all have varying times I've had them. The one I've had longest is one of the small ones. I've had her since early March. The rest I've had a little over a month, for the most part.

What you are seeing just ‘might’ be the effects of PPS too. If the conditions were not favorable from where they were bought at, did you help them to slowly adjust to proper conditions?

http://crabstreetjournal.com/xoops/modu ... toryid=165

What substrate or combination of substrates are you using? How deep is it?
I used to use jungle bedding, a small amount of gravel, a small amount of calci-sand, some moss, and a small amount of crushed oyster shell all mixed together.

Calsi sand can actually be harmful to hermies. If it gets damp and begins to dry it is known ot harden. A few crabbers who have tried mixing this with eco earth found that when their hermies burrowed to molt that after a period of time they went a searching for their molter to find them ‘cemented’ within their shells dead. Jungle bedding (T-rex) is a red cypress mulch and should not be used in a hermies tank. Cypress is a conifer. Coniferous wood/needles are toxic to crabs when ingested and hermies are known to eat their substrate.

However, because of your advice below, I have changed it to a combination of jungle bedding, moss, and coconut fibers. I always keep atleast three inches in my tank, sometimes more.

I am sorry but I am a little puzzled about the advice below? I have gone through this thread a few times and do not see where it was suggested to use Jungle bedding? Perhaps this area was in reply somewhere else? If so please do seriously consider removing the jungle bedding, it is NOT hermie safe. If one opts to use such substrates it is highly recommended it be 100% coco fiber.

What do you feed your hermit crabs?

I used to feed them a combination of many different hermit foods, including, but not limited to, two types of pre-made hermit crab foods (these had preservatives), crushed egg shells, freeze-dried fruit, freeze-dried vegetables, dried leaves, and some calcium supplements.
Since I had mixed those all together before, I had to get rid of even the good things. I recently changed it to crushed egg shells, dried shrimp, a calcium block (I looked at the ingredients and it seemed to have no preservatives, getting the powdered calcium was too much on my budget at the moment), dried papaya, dried raisins, and rose hips. I have mealworms but they could mold and such, so I'm saving them for when I can keep a good watch on the food and have a separate bowl to put just those in.

Honestly the calcium block isn’t needed. There are other foods that contain calcium that can be fed, one which you already supply as in egg shells. Another that is less expensive is cuttlebone, but can also be from foods you eat before seasoning them. Please check Hermit Crab Cuisine for foods.
http://www.hermitcrabcuisine.com/
Please make sure your hermies get one item from the hermie food pyramid daily.

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?
I use distilled water. Whenever I clean things, I use tap water with a dechlorinator and stress coat, the brand is API.

Distilled water in the hermies water dishes is fantastic. No fuss, no mess or concern as to when the public water company flushed their lines out which would cause the chlorine content to be higher. If you mean cleaning items like huts, woods, etc. one can use tap water. I then have a bucket (one used for hermies only) with API (no stesscoat) and give them a dip in it. This saves on the expense of buying bottled distilled water.

What brand of sea salt are you using to supply your hermit crabs with salt water?
I originally used HBH hermit crab salt, but because of your advice and looking through the crab care section in that area, I recently got Oceanic natural sea salt mix

FANTASTIC!! After mixing did you leave it sit in a bottle and shake it for about 12-24 hours?

What heat source are you using and where is it positioned?
I am only using a light right now because our house is very hot at the moment. We do not have an AC on this side of the house, so the terrarium has stayed within the temperature range according to my thermometer within the terrarium. During the colder seasons, I also put a heating pad underneath the terrarium.

Heating pad as in a reptile UTH, or a human heating pad? Here we do have central air but keep it set on 78*F even during the summer. We have thermostats on all tanks and iso’s and even at that the UTH’s are kicked on a few times during the day.

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)?

I always stay within the range specified on my thermometer/hydrometer for hermit crabs. Right now, the temperature is 79 and the humidity is 72.

Are you monitoring the substrate temp too? Any idea what the temp is? (cool and warm side) If it is that warm, and your substrate temp is warm enough, and you have a window in your room for natural light you can turn off the light bulb. Just try to keep the tank out of direct sunlight so not to overheat the hermies. There is normally a difference between substrate and air temp of the tank.

I am sure with a little tweaking your hermies should be a bit more comfortable and hopefully live a longer happier life with you.
See… a little more involved than Yahoo Answers, and at the same time also not from a forum that needs to go to another site to find the answers to help you. As with Yahoo answers, please do be careful as to where you search for help. Welcome to HCP!!