Marine Hermit Crabs

For discussion and photos of all of the non-hermit crab pets we hold dear, including other crab species.

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Guest

Cannibalism

Post by Guest » Thu Oct 23, 2008 9:10 am

I've got five hermies, three large ones and two small ones. Recently, my larger ones molted for the first time since setting up the tank... which has been over five months ago. The recently molted hermie was a beautiful pink and gray color post molt.... and he seemed to be doing fine. He had a nice big shell to back in to for safety. But.... the next morning I woke up to find that the other hermies had killed him and were feasting on his body. They've never done anything like this... so I was surprised and sad. I'm in the process of setting up another, larger tank, to keep this from happening again. I'll transfer the newly molted hermies to the new tank after molting.

My tank is a 15 gallon, I have no live coral or rock, and my MHC's do just fine. I'm pretty new to the salt-water business, but it's been fun to see them interact... and it's totally been worth the cost... although, with a 15 gal I got off pretty easy. lol

Mine are extremely particular about shells. I've tried all sorts, but they always move back into their old shells. Regardless of their shape or size. I also take mine out occasionally... which they seem to enjoy. I live on the Gulf Coast and they are EVERYWHERE.... you often see them sunning in the sand.
They love pellets (Crab & Lobster Bites, I think they're called). But they also enjoy seaweed, lettuce, and of course algae. Beware about the seaweed though... it makes for a nice mess. Be prepared to clean up the leftovers when the crabs no longer show interest. In general, they'll eat almost anything.

The salt-water fish store that I buy supplies from sell MHC's in abundance. They also keep them for tank cleaning. Essentially, it's only illegal to take them from the beach... but that only applies to certain states.

Does anyone know how to tell males from females? And how do you embed pictures in a post?


Topic author
Guest

Post by Guest » Mon Nov 17, 2008 2:36 pm

Hi

Just an update on my three new MHC's :) I sure appreciated your help Caroline. So far so good. I have not had any problems with them nipping at more corals and my Hawk fish seems to be leaving them alone.

I do want to check on one behavior though. Very often, I look in the tank and two of them (the two that switched shells) are upside down tucked inside of their shell. The shells are quite big for them but that is what they choose. There are smaller shells available. Do you suppose they are not able to handle the shells or is this common or are some of my fishes bothering them?

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annopia
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Post by annopia » Mon Nov 17, 2008 6:36 pm

hmmm...the only time i ever see mine on their back in the open is when they are in a shell fight (being attacked by another crab). was another crab nearby when you found them like that? if so, you might have disturbed the shell fight and the aggressor left quickly. as for the shells being too big, no worries, the water makes everything so light that they can wear shells our MHCs would never have dreamed of. as long as you have a good range and they have an option, you should be good (ive got 55 extras in my tank)..


Caroline
26 LHC: 6 PPs, 5 Es, 1 Straw, 6 Ruggies, 2 Indos, 1 Blueberry, 4 Violas, 1 Aussie


Topic author
Guest

Post by Guest » Mon Nov 17, 2008 11:08 pm

One of the other crabs may have been near. I will have to pay more attention next time. Boy they sure do love silversides - they run for the food unlike my LHC's. :) It is quite interesting the difference in how shy the LHC's are compared to MHC.

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annopia
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Post by annopia » Tue Nov 18, 2008 1:26 pm

oh yes, my MHC have no fear of me. when i reach down with the fresh fish chunk of the day (or one of the sea veggies cubes), several will literally reach up with their claws and grab it. I have so many pics of them all eating with reckless abandon, something i rarely see with LHC. i haven't given them silversides though, usually i buy the fish from the grocery store and freeze it in chunks. they really love calamari the best.

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Caroline
26 LHC: 6 PPs, 5 Es, 1 Straw, 6 Ruggies, 2 Indos, 1 Blueberry, 4 Violas, 1 Aussie


Topic author
Guest

Post by Guest » Thu Jan 01, 2009 11:18 am

Hi everyone. Happy New Year :)

I have a question about my MHC for Caroline or anyone with experience. I was wondering if they shed their skin like the LHC? I got up their morning and there is what appears to be a dead crab out of it's shell in my tank. I don't know if it is a crab or an exo-skeleton. I see two of my crabs and they appear to be fine. The other one usually hangs out behind the rocks so I do not see it very often. Should I take it out? The fish seem to be picking at it.

I did not see any of my crabs digging down like the LHC's do, but one of them did sit in it's shell for the last couple of days in the corner. Is this how they molt?

Thanks for your help.

since MHC don't eat their exo, its very possible that what youre seeing is the discarded exo. the key is if it has an abdomen: if it does, it is the crab, if it doesn't, its the exo.

Caroline

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Post by OIF_VET » Thu Jan 01, 2009 1:07 pm

Sounds Like the Hermie Passed. :(
When I had my Marine tank up and running, I would sometimes find a dead hermie.
Not to sound gross, But, I left the carcass in the Tank for the fish and other hermits to eat.

As for Molting, I am fairly certain that they do not dig down. Instead I believe they curl up as deep as they can into the shell and molt from there.
I am not 100% sure on this.
Good luck to you.

On a side note.
If you have found that the hermit is dead...I would do a water quality check.
MHCs are fairly hardy and can with stand drastic fluctuations. Hence this is why some Aquarium shops will sell them to help establish a Marine Tank.
Welcome to the HCA! Advice for the Stressed, Owners and Crabs alike.
Been Crabby Since 8/16/05 Land, Marine Hermit Crabs Since Summer '04
Currently Have 4 PPs. I have Countless Successful Molts!
MY "Lil Dudes"

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annopia
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Post by annopia » Fri Jan 02, 2009 8:05 pm

I think its most likely that you're seeing one of your MHC's exoskeletans. they shed very quickly on the surface and abandon them (they do not attempt to eat it). Many many times I have gotten a bit freaked about seeing this "dead" little body, only to (thankfully) realize it is only exo. Easy to determine: if the abdomen is attatched, its the real crab, if there isn't an abdomen, its an exo. i hope the later is true in your case.

Caroline
26 LHC: 6 PPs, 5 Es, 1 Straw, 6 Ruggies, 2 Indos, 1 Blueberry, 4 Violas, 1 Aussie

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annopia
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Post by annopia » Fri Jan 02, 2009 8:11 pm

Here's a shot of one of my scarletts, Ismene, right after a molt (it took her less than 4 minutes to shed the entire exo):

Image

her disregarded exo left in the tank:

Image

after realizing that they don't eat the exos, ive started taking them out and preserving them, to show how each crab grows over time.

Caroline
26 LHC: 6 PPs, 5 Es, 1 Straw, 6 Ruggies, 2 Indos, 1 Blueberry, 4 Violas, 1 Aussie


Topic author
Guest

Post by Guest » Mon Jan 05, 2009 5:33 pm

Caroline

Thank you for your response. Sorry it is taking so long for me to reply. You are right (YEA). It was an exo and all three are alive and well. Unfortunately, I did not get it out of the tank and have no idea where it is - the fish may have eaten it I suppose.

Anyway, thanks again.

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annopia
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Post by annopia » Mon Jan 05, 2009 7:21 pm

Chryss wrote:Caroline

Thank you for your response. Sorry it is taking so long for me to reply. You are right (YEA). It was an exo and all three are alive and well. Unfortunately, I did not get it out of the tank and have no idea where it is - the fish may have eaten it I suppose.

Anyway, thanks again.
thats great! don't worry about not taking it out, some fish might find it tasty, even if the crabs dont. i take them out because i preserve them and plan to mount them later.

Caroline
26 LHC: 6 PPs, 5 Es, 1 Straw, 6 Ruggies, 2 Indos, 1 Blueberry, 4 Violas, 1 Aussie

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