Jump to content
flutinkat

Marine Hermit Crabs....lots of questions

Recommended Posts

flutinkat

So I have a really different situation. I'm a land hermit crab person just finished building a 75g terrarium for my 18 LHCs. You can see the crabarium here:

http://i1308.photobucket.com/albums/s616/flutinkat/Crabitats%20and%20Projects/IMAG0632_zps760dd826.jpg

 

It has two 5.5g tanks in it, and the purpose of these is to help simulate as close to a natural environment as possible. The one you can see in the picture is the saltwater one. The other one is freshwater. I have questions about each tank, and I'll describe the current setup. Right now, I have the API water test kit as well, which should have all the test I need for freshwater and saltwater as I understand it as well. Everything was just set up today. I'm a total newbie - I kept some gouramis for their life span, but that's about my total experience with fish, so assume I know nothing.

 

Saltwater: I have coral substrate in there along with a few chunks of actual coral. It's got an internal Tetra filter in there as well as an airstone putting off a ton of bubbles. I'd love to put a few marine scarlet hermit crabs but I'm totally lost on what to feed, what environment is needed, how many in that tank, what kind of shells to use, etc. I'd also like some help with what to plant in the tank. The ramp is made of needlepoint canvas, and the land hermit crabs use it so they don't drown.


Freshwater: I have washed playsand in there along with some river rocks. It's got the same setup - internal 10g filter, airstone, needlepoint canvas ramp, etc. I want to plant this tank, and I'd like to keep some tank cleaners (maybe small bottom feeders, ghost or cherry shrimp, snails, etc).

 

I'd really appreciate any help on either tank! Google is just not very helpful and I would rather come to a source I know I can trust. Thanks for any and all help!

Share this post


Link to post
seabass

For Scarlet reef hermits, feeding is not a problem as they will eat prepared fish food pellets. You just need to provide some empty snail shells that are a little larger than their current shell.

 

I imagine that you would run the marine tank basically the same as a display refugium (with decorative macro algae). That might give you a place to start researching. Let us know what you need help with.

  • Like 1

Share this post


Link to post
jcarman81

Scarlets are pretty good scavengers, but a bit lazy in my experience. The marine hermits are opportunists and eat whatever they can get their claws on. Good marine flake or pellet food is good along with the algae that will naturally grow in your tank. Make sure to give them a few shells to move into as they grow.

  • Like 1

Share this post


Link to post
flutinkat

A few questions based on new googling:

What is live rock exactly? Would my coral that's been out for a while qualify? I'm having a hard time getting a good answer.

So as I understand it, the marine hermits aren't picky about shells? Land hermits are super picky, so I'm just making sure.

What is NOT good to plant in the tank?

Thanks!

Share this post


Link to post
lakshwadeep

I suggest going to the library section (top left) and reading all the articles. Most marine hermits are not picky about shells or food (there are some exotic ones like the staghorn that actually has coral for its shell or others that filter feed from a hole). This is a neat site on various marine species:

http://www.recif.be/article/hermit.htm

 

This article explains what live rock is and why you should probably remove the tetra filter media. Also, remove the bubbler because saltwater bubbles will create a coating of salt ("salt creep") outside the tank.

http://www.wetwebmedia.com/ca/volume_2/cav2i5/Filtration/Filtration.htm

 

Note that most of the "plants" in marine tanks are actually algae (there are a few higher plants like seagrasses and mangroves), so you should go to that relevant subforum for more info on desirable and undesirable macroalgae.

  • Like 1

Share this post


Link to post
jcarman81

Live rock is rock that has the beneficial bacteria living in it and helps with your biological filtration. The beneficial bacteria are present everywhere, just not normally at the time you first set up your tank. Many reefers start off with a mix of live rock and base rock. The base rock is extremely cheap when compared to live rock.

 

This forum is a great source of information and there are a lot of very helpful people here that will help you out. Good luck with your tank.

  • Like 1

Share this post


Link to post
flutinkat

Thank you! I'll continue looking. One thing I'm not finding yet is how cyanobacteria originates - obviously, with the absence of actual fish, the rules are going to be different.



PS I'm more than happy to change the tetra filter, but the bubbler has to stay. The bubbler is what creates humidity for the land hermit crabs, and without it they will probably die.

Share this post


Link to post
flutinkat

EDIT: After thinking about it for a while, I realized I can double up the freshwater bubbler. I'll see if the water flow is too strong for the shrimp that will go in there.

Share this post


Link to post
jadedanime

I'm confused as to why the marine hermits need a ramp? As they are fully aquatic... You wouldn't want them climbing up onto the land, getting confused and taking a plunge into the freshwater. You also don't want the land hermits to take a saltwater dive. Actually I'm confused as to why you would need the ramp at all. Because you don't want the land hermits to take a dive into either, or they have the chance of drowning. Why not just build a small puddle for the land hermits, so that they can use it and not deal with the drowning issue altogether? And then block off the smaller tanks.

Share this post


Link to post
flutinkat

The land hermits have no chance of drowning - that's the point of the ramp. Do you keep land hermits? Many of the experienced land crabbers have large pools that help simulate a more natural environment. Also, yes, land hermits do need freshwater and saltwater - in fact, the only way they can possibly reproduce is in an environment with large saltwater pools. Even without reproducing, they will die if they cannot keep a proper salinity level in their shell water, as well as a water depth that they can safely submerge to.

 

If I just wanted to keep marine hermits in an isolated tank, I would do that. I may wind up doing that anyway, but I can't seem to get the basic questions answered. If it turns out that I cannot keep marine hermits in there safely, which is doubtful because I know it has been done by some very good crab specialists, then I won't, and I'll just plant it. No problem. The point is to create a simulated natural environment, which is my responsibility as a pet owner, especially with wild-caught animals. Actually, my biggest reservation is that I have ethical issues with putting any complex animal in a tank that small.

 

I have done the reading, but most of the reading is highly technical and doesn't offer basic definitions and information, so it's been mostly useless without the basics answered. Hence the questions, which have mostly been answered by "go read."

 

I just wanted to point out that this whole thread has been very frustrating. I don't know if many new members react like this, but this is the most unwelcome I've ever felt in any forum.

Share this post


Link to post
flutinkat

Something I've been thinking about in regards to the "aggressiveness" I keep reading about with marine hermits - many of these behaviors are seen in land hermit crabs with insufficient resources. Land hermit crabs kept with inadequate protein supply or shell supply will often murder tank-mates for resources, but if they are properly cared for, they are very docile.

Land hermit crabs are complicated critters with a myriad of needs and very specific care, so it stands to reason that marine hermits are the same way. I'm also a little leery of feeding fish food, since most fish foods contain ingredients such as copper or ferrous sulfate that are specifically designed to kill invertebrates. If we just don't know much about marine hermits beyond "they eat food, they wear shells," that's fine, but I strongly suspect we know more about their behavior than that, and that this would be the place to get that information. I just wish someone would share.

Share this post


Link to post
jcarman81

You may get some better help in the inverts section of the forum. There are a lot of people in there that may be able to help you with the more specific questions regarding crab keeping.

  • Like 1

Share this post


Link to post
flutinkat

Thank you - I appreciate the help!

Share this post


Link to post
seabass

Live rock provides the biological filter for most of our marine nano tanks. The guideline is usually one pound per gallon of water, but if you will be just keeping hermit crabs, you could get by will less. Often we use additional filters (like activated carbon and filter floss), so your internal filter is fine to use.

 

I assume that Cyano is commonly present on live rock and coral frags. However, it is only when there is a bloom, that we notice it and say we have Cyano (which is usually due to excessive organics and nutrients).

 

I may wind up doing that anyway, but I can't seem to get the basic questions answered.

Which questions aren't being answered?

 

Hence the questions, which have mostly been answered by "go read."

You will have to do a some research. Most of our members don't have much knowledge/experience with land crabs.

Marine hermits are opportunistic feeders. We usually use them as part of a cleanup crew to scavenge left over food and to clean up dead/dying livestock.

 

Something I've been thinking about in regards to the "aggressiveness" I keep reading about with marine hermits - many of these behaviors are seen in land hermit crabs with insufficient resources. Land hermit crabs kept with inadequate protein supply or shell supply will often murder tank-mates for resources, but if they are properly cared for, they are very docile.

Yes, if they are well fed, they will be less aggressive. Again, they are opportunistic feeders and are fairly decent reef tank inhabitants when well fed. Having extra available shells also helps keep them from killing snails (for their shells).

 

 

Land hermit crabs are complicated critters with a myriad of needs and very specific care, so it stands to reason that marine hermits are the same way. I'm also a little leery of feeding fish food, since most fish foods contain ingredients such as copper or ferrous sulfate that are specifically designed to kill invertebrates.

Our fish food is for reef tanks. We feed it to corals and other inverts without problems. However, you can even make your own food out of natural ingredients if you prefer (a number of reefers do).

  • Like 1

Share this post


Link to post
polarblair2000

Hi there, this sounds like a pretty awesome project.

 

Obviously Land hermit crabs are pretty complex animals. I don't speak for everyone but in reality hermit crabs are not really thought of much more than a part of a reef tanks clean up crew. A collection of smaller creatures we first add to our tanks to help keep it clean. This includes snails, crabs, hermits and other things.

 

Hermits seem to look after them selves in a regular reef tank other than providing larger shells there's not much you need to do.

 

There may be some people with more info on these guys that your looking for but I would try the invert sub forum for more answers.

 

Marine fish food does not contain copper, otherwise all our corals would be dead so I wouldn't worry about that.

 

Really hermit crabs can be a bit of a pest to the reef keeper. The steal food and trample over corals - they are interesting little guys but I've not seen anyone solely dedicate a tank for them before on here so there might not be as many experts as you might hope.

 

Be sure to post pics when it's set up! Would like to see this progress :)

 

EDIT: Seabass beat me to most of those questions :)

  • Like 2

Share this post


Link to post
flutinkat

Thanks for the considerate replies. I appreciate the detailed responses; I'll post in the invert forum and hopefully there will be more people that know a little bit more about it.

Here's the questions I have right this second:

1) How many crabs should I get for a lightly stocked 5.5g tank? I'm assuming 3 would be reasonable, but would like a second opinion.

2) Is salt creep going to be an issue for the tank dwellers, or is it a cosmetic issue?

3) Almost all the fish food I find seems to contain either ethyoxquin (sp?) or copper/ferrous sulfate. Both are slow known poisons for many inverts (think human lead poisoning). What brand would you recommend?

4) Is there anything I should look for in live rock or avoid?

5) Most importantly right now, what should I do to begin cycling the tank? Or is it different for marine tanks? This is the biggest thing I keep running into, since most of it contains jargon that I really don't understand and have no point of reference for. My main priority is to start the process of making the water inhabitable.

6) What should I plant the tank with? The pet store guy says that you can't plant a marine tank, but he's kinda full of crap on most other topics so I'd like a second opinion from someone more educated.

Share this post


Link to post
fretfreak13

1) How many crabs should I get for a lightly stocked 5.5g tank? I'm assuming 3 would be reasonable, but would like a second opinion.

2) Is salt creep going to be an issue for the tank dwellers, or is it a cosmetic issue?

3) Almost all the fish food I find seems to contain either ethyoxquin (sp?) or copper/ferrous sulfate. Both are slow known poisons for many inverts (think human lead poisoning). What brand would you recommend?

4) Is there anything I should look for in live rock or avoid?

5) Most importantly right now, what should I do to begin cycling the tank? Or is it different for marine tanks? This is the biggest thing I keep running into, since most of it contains jargon that I really don't understand and have no point of reference for. My main priority is to start the process of making the water inhabitable.

6) What should I plant the tank with? The pet store guy says that you can't plant a marine tank, but he's kinda full of crap on most other topics so I'd like a second opinion from someone more educated.

 

1.) Depends on what species you're doing.

2.) Just cosmetic, really. May slightly effect salinity, but not enough to make a real difference to the hermit crabs.

3.) My hermit crabs eat Spectrum pellets with no ill effects.

4.) The more porus the better because it has a larger surface area for the bacteria to inhabit. There are some pest algaes you can watch out for, I'll edit this post with a link.

5.) Just put some live rock in there and maybe a little crab food (organic material for the bacteria to eat). Give it a week, then test your water and see where you're at. Honestly, since you're stocking so lightly bio-load wise, you could probably just get away with just using the live rock without the food booster.

6.) Macro algae! That guy obviously doesn't know what he's talking about...

 

I didn't read the whole thread. Are you familiar with fiddler crabs? They're a pretty awesome little saltwater crab that actually need land to escape the water. Just don't have shells like hermits.

  • Like 1

Share this post


Link to post
seabass

1) How many crabs should I get for a lightly stocked 5.5g tank? I'm assuming 3 would be reasonable, but would like a second opinion.

That's totally reasonable. I'd get a couple of Dwarf Blue Legs, and a Scarlet Reef Hermit (but any combination should be fine).

 

2) Is salt creep going to be an issue for the tank dwellers, or is it a cosmetic issue?

It is a cosmetic problem; however, I know that it can harm coral if it falls on it. I don't know if it would be a problem for a crab that could avoid it; but I assume that it could be harmful. I wouldn't put an airstone in that saltwater side.

 

3) Almost all the fish food I find seems to contain either ethyoxquin (sp?) or copper/ferrous sulfate. Both are slow known poisons for many inverts (think human lead poisoning). What brand would you recommend?

The choices are endless, and they are not picky at all. They are extremely hardy and will eat any prepared food. Take your pick; I'd probably go with frozen or small pellet food.

 

4) Is there anything I should look for in live rock or avoid?

Nothing that will harm the crabs. Pest algae (and anemones) can be a problem.

 

5) Most importantly right now, what should I do to begin cycling the tank? Or is it different for marine tanks? This is the biggest thing I keep running into, since most of it contains jargon that I really don't understand and have no point of reference for. My main priority is to start the process of making the water inhabitable.

Add the live rock (about 4 or 5 pounds) and wait for ammonia to become undetectable for a week straight. Then you could start adding your crabs.

 

6) What should I plant the tank with? The pet store guy says that you can't plant a marine tank, but he's kinda full of crap on most other topics so I'd like a second opinion from someone more educated.

There are all types of display macro algae available. Note, some varieties can go "sexual" and dissolve in your tank if conditions become unsuitable (like low nutrients). This will release all the nutrients and could crash the tank.

 

 

Edit: Looks like fretfreak13 already beat me to it with a good response.

  • Like 1

Share this post


Link to post
Tamberav

Cool project! I wish I could help but I don't know much about technical caring for hermit crabs, just that they are fairly easy compared to other reef animals. The land hermits sound difficult!

 

If something goes wrong... a lot of times fish die and the hermit-crabs live on eating them giant fish snacks. I have one and he has been a happy little guy for 2 years now.

 

Cycle:

 

You will need a test kit for ammonia, nitrite, and nitrate.

 

First you need a ammonia source, for live rock.. some die off will happen in transport to serve as this.

 

After a few days you should see a spike in ammonia, test every few days until it reads zero.

 

Next you test for nitrites, it will spike and then drop to zero.

 

Then you test for nitrates, at the end of the cycle this will peak. You do a partial water change to remove the nitrates then add your hermits.

 

 

You can DEFINITELY plant a marine tank. Lots of people do on these forums. There are many colorful macroalgae's, you will just need proper lighting for them depending which you choose.

 

If the rock had very little/no die-off (depending how long it was out of the water) then the tank may not cycle at all. You are most likely safe to add hermits right away with live rock since they are a small bioload.

 

Edit: Looks like I got beat by 2 people :)

Share this post


Link to post
RC1313

If I was you I would look into halloween hermit crabs. I've always thought those were cool!

  • Like 1

Share this post


Link to post
flutinkat

Thanks! All of those look very cool. I'll do some research and see which species need the least space and which I'd prefer. I've always had a soft spot for the brightly colored crabs, so this should be super fun.


I did do a water conditions check tonight and this is what I came up with. Nothing has been added, so the ammonia must be from city water or possibly land hermit waste.

pH: 8.0

Ammonia: 1 ppm

Nitrite: .25 ppm

Nitrate: 0 ppm

So I'm assuming it's already started the cycle. However, I'll definitely get live rock ASAP (maybe next weekend when I can visit this great store out of town). To make sure, I need all those levels to drop to zero before adding any animals, right?

 

Can you tell me more about pest algae?

 

Can you tell me more about fiddler crabs and halloween crabs?

 

Can you tell me more about macro algae? Specifically, information on what kinds are beginner-friendly is helpful.

 

You mentioned coral being harmed; is there a possibility of making my current coral "live coral?"

 

Can you tell me more about low nutrients and how I can avoid that?

 

Is there a non-chemical way to raise my pH a little bit?

 

Thank you! I'm still continuing to devour articles, which is pretty much just generating more questions. I probably should have been a biologist; I get like this with every new animal.

Share this post


Link to post
seabass

To make sure, I need all those levels to drop to zero before adding any animals, right?

Ammonia and nitrite should become undetectable. Nitrate will probably have to be exported via water changes. You should be using distilled water, not tap water.

 

Can you tell me more about pest algae?

It could be any algae you don't want. However it usually is Bryopsis, hair algae, or bubble algae.

 

You mentioned coral being harmed; is there a possibility of making my current coral "live coral?"

I was just referencing that animals can be harmed by direct exposure to salt. Dead coral can essentially support bacteria (like live rock), but it will not become coral again. Coral will have more demanding requirements.

 

Can you tell me more about low nutrients and how I can avoid that?

Phosphate should be around 0.03ppm, and nitrate should be around 10ppm. It will take a decent low range phosphate test kit to determine the appropriate phosphate level.

 

Hermit crabs are easy, but macro algae can be much more difficult.

 

Is there a non-chemical way to raise my pH a little bit?

Don't worry too much about pH. It will be a little low while the nitrogen cycle is becoming established.

 

Oh, and what is dKH and sg? Under water conditions: http://www.liveaquaria.com/product/prod_display.cfm?c=497+501+620&pcatid=620

Alkalinity and specific gravity (salinity).

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recommended Discussions

×
×
  • Create New...