New crab: he's just so BIG

[shannonrenee4]

I had two medium hermies and I was looking for another one. There is nowhere around here to purchase them. My cousin told me she knew a place that sold hermit crabs in her town. I called there and ordered a medium-sized purple pincher. My cousin picked it up for me and brought it here today. I was not prepared for the size of this thing. I introduced him to the other crabs (who are way smaller) and realized he was too aggressive to keep in the main tank (at least until he de-stresses). I moved him to the Iso tank but honestly, I'm afraid the plastic tank is just too small for him.
I contacted the pet store and they informed me it was "medium-to-large" and his shell makes him seem bigger than he is. (He does have a very large natural shell). They told me he lived in a tank with hermit crabs of all sizes and he was never aggressive towards them.

I don't know. I just can't figure out what to do. I can't bring him back to the pet store because it's 3 hours away (where my cousin lives), I can't put him in the main tank just yet, and he looks so miserable in the isolation tank. (He's trying desperately to get out actually).

What do I do?

[erikleeson]

Your new hermit crab was most likely not being aggressive, many times a new crab will engage in what we call "antennae wars" and sometimes pushing contests. Hermit crabs naturally travel in groups and frequently determine the leader crab of the group by having these displays. There is nothing to worry as these are completely normal and harmless actions. The only aggressive act hermit crabs have been known for are shell fights, and these can be detected by chirping noises. Ultimately you cannot stop these by separating the crabs as the attacker will attempt the fight again. This sounds unlikely in your setting as the newbie is much larger, so I'm assuming it was just a greeting, not aggressiveness.

As for the problem, Hermit crabs should not be kept in plastic tanks because moisture can easily escape and gets dirty easier. How big is your tank? Try to get a 20 gallon tank so that all of your crabs have enough space to be alone if they wish. This new crab is also going to need deeper substrate for molts - I'd say no less than 6 inches. Keep it damp.

You could try a 10 gallon tank but with a medium large its really better to have a 20 gallon, besides then you can have larger climbing toys and etc..

Basically larger crabs are the same care except on a larger scale. All the items in the tank must fit the crab's needs. Can he fit in the shelter without being crowded? Can he fit in the water dish? Does he have enough shells in his size? Can he climb without breaking anything?

I'd say that by spending a little money you can create a nice environment that will suit the new crab fine and well be better for all the crabs overall.

Hope all goes well!

[shannonrenee4]

Thanks for your reply.

I have them in a ten-gallon tank right now. (I was only using the plastic one as the isolation tank, with a covered lid & gauge for correct humidity). I have honestly put so much money towards these hermit crabs, I simply can't afford to purchase a 20-gallon tank. I had just built a second level so there's more room in the tank now than before. Yes he can fit in the water dishes and there are plenty of hiding places for the crabs to be alone. But still, I am worried about his size for general mobility around the tank. It's a bit of a maze at the moment. (Until I get my new corner water dishes and differently-shaped hideaway). Honestly, I wasn't expecting a medium-to-large hermit crab. I ordered larger shells because the ones I had were not big enough. But besides that, I don't know what else I could do to accommodate him. Here's some pictures I just took with my cell phone, what do you think? Is it too small? (The other two hermit crabs are hiding underneath the upper level).
The new hermit crab doesn't look that big in these pictures, but when he's next to my other two, he's a monster.

Front picture of the tank. (the new hermit crab is on the upper left corner)


You can see the top a bit better in this one:


Here's the new guy going up a climbing branch:


Closer:


There's a hiding hut and various shells on the lower right side of the tank, but you can't really see them in these pictures.

[erikleeson]

If thats the case I think its fine. He has plenty of space, it looks fine. I have 2 crabs that size and 8 others smaller and they get around fine in my tank.


My tank is 29 gallons.

[ladybug15057]

First, is that a hole in the tip of the new guys shell?
Second, I would suggest to keep him in iso for at least a week. He is new, has been through a LOT and will have more of his wild instincts still. He will feel the need to fight for food, water, and shells. By giving him iso time he will have time to adjust to knowing he should not need to fight for these things. Even though your other hermies are smaller and chances are he would not fit into their shells, all he relates to is there is a shell with another in it so it must be comfy. Until he gets that hermie out of it and tries to slide his bottom into it he will not know it is too small. Meanwhile your original hermie could be seriously injured or even killed. If you only have the 2 other hermies who are smaller, once his iso time is done there 'should' be room for the 3 of them, but you may wish to wait until you get shells his size and offer them a few days to him in the iso tank for him to have the chance to try them on.

[Wai]

Since you need to isolate the new guy, you'll need to use the critter keeper for now (unless you can find a glass tank). Find some plastic wrap and cover the mouth of the critter keeper, leaving at least two air gaps in the corners. Spray the underside of the plastic wrap with dechlorinated water, then put on the critter keeper lid. Wrap the whole critter keeper with a dark coloured towel, but only cover half of the lid. Measure the temperature and the humidity and if all is well, try putting in the new guy. Leave plenty of spare shells for him. He needs to get out of his "wild" mode (where you have to fight for everything) and into "captive" mode (where you don't need to fight for everything). Critter keepers aren't ideal, but this may be the only thing you can use for the time being.