HCA: Hermit Crab Association

im so angry right now!! I got this crab i had for a few years and he has had 2 other tank mates and BOTH are dead because he ate them while molting. Tt was my fault because the dirt was not deep enough but now i decided to do this one last time. I just put the new tank mate in their and they are about the same seize this time because the first one was so tiny and the second one was to big. but no sooner did i put him in Gumbo(the old one) got on top of the new one while he was in his shell and rocked him back and forth nonstop until i rose up and made a shadow and he hid in his shell and the new one popped out and gumbo popped out and started shoving him into a wall then the new one got sick of it and shoved back while both were having a feeler fight. then the new one oped his claw about to grab gumbos leg and i made my shadow again and they both hid. I put the new one in a circle plastic container with a lid that does not go with it and a plastic water dish holding the lid down. a few days later Gumbo easily moved the lid over and got in the container and it looked like they fought some more and gumbo was in his shell flipped over. I took them both out and got rid of the container. later i kept hearing MORE noises. and i turned to see Gumbo holding on to the new crabs shell while the new crab was trying to get away. I don't know why he is doing this when he had FIVE shells near by. he even switched into one of them. Im seriously about to just return this new one and just either let gumbo live the rest of his life alone or ditch him somewhere or give him away. This crab has a bad and selfish attitude no matter what he has he ALWAYS wants more! when I got Gumbo from a painted shell crab vendor he was in the tank doing the same thing to another crab while it was in its shell. he even did the same thing to the first one who was about the size of his claw before he lost interest. the second one who was the bigger one he did it to but it beat HIM up instead and he stopped until he ate it. now HES in he isolation plastic container. the new guy is just sitting in the corner

I'm sorry you're having so much trouble introducing crabs. It's rare, but there have been crabs who just could not be kept with others talked about here before. But usually it's something environmental going on. Too little substrate, not enough protein, not enough or the wrong types of shells, etc. Also some crabs go a little crazy just before a molt. ....And then there's the well documented aggression issues many (but not all) crabbers have had with Es (not sure what species you have).

Can you answer these questions just so we can see if there's any obvious possible reason?

1. What kind of substrate is used in your tank and how deep is it?

2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?

3. Is a heat source used in the tank? If so, what?

4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?

5. What kinds of food do you feed and how often is it replaced?

6. How long have you had the crab and what species is it, if known?

7. Has your crab molted, and how long ago did it happen?

8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?

9. How many crabs are in the tank and about how large are they?

10. How many extra shells are usually kept in the tank, if any?

11. Have there been any fumes or chemicals near the crabitat recently?

12. How often do you clean the tank and how?

13. Are sponges used in the water dish? If so, how are they cleaned?

14. Has anything new been added to your crabitat recently?

15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?

Bocoom,
Hi. I have a 14 year old Purple Pincher. She has a history of not tolerating other crabs. From previous discussions on HCA, I was told this is because if a crab lives in isolation for too long, they stop liking other crabs. It is possible it is not fixable.

However, now that I think about it, the environment during all these attempts was barely tolerable. I was doing the best I could, but it took a while to figure out what I was doing wrong with temperature and humidity. So maybe my crab was more stressed than I knew at the time.

I am inclined to believe that isolation is the problem though, because the incoming crab didn't seem to be stressed. I did all the recommended isolation/de-stressing procedures for the incoming crab. And the incoming crab was noticeably polite and willing to make friends. But my older crab, who is friendly with me (to the point of requesting attention daily) was murderously aggressive with the newcomer for no reason. I saw this, it was uncalled for.

After two attempts, the incoming crab lived in a smaller tank next door for a year and a half. He made repeated attempts to get attention, but the larger crab faced in the opposite direction. Eventually, I gave the newer crab to a crab rescue so he would not become psychologically damaged as well. He is doing well there, I'm told. I ask about him periodically.

As for my original crab, when she realized her neighbor was gone, She appeared (in my opinion) unhappy and frustrated. Oh well. I do my best to give all the attention she wants, in her own way.

Prolonged isolation from other crabs truly is the most likely cause. This can often be seen in other social animals as well. Case in point, I had a pet dove growing up who was hand-raised from a baby and was not in contact with other doves. He loved people, but could not stand other doves. Every time we tried to get him a mate (thinking that he may have liked an actual girlfriend instead of mating with socks and people's feet), he would be so aggressive toward her that it was shocking. We eventually stopped trying and left him to his socks.

Well after a few days in the same plastic container he managed to get out again. I just said screw it and went to work. I came back excepting the worst but they were just sitting behind the wood decoration casually touching feelers. I guess that sorted it out. peace has returned to the tank. maybe ill make some chicken livers for them to celibate