Aggressive Crab

[crabbykat]

Hello!
Behavior Question: I have a medium sized PP that was in with my main colony. He had a small bit of his leg shell broken so I put him in
isolation. He molted (although his hurt leg is deformed now). I have been trying to reintroduce him into the colony again but he is either very aggressive towards the other crabs or they are very aggressive towards him. I suspect that the shell damage he suffered was the result of a fight. He is a super cool crab but is just my problem child. I would really like to get him back into the colony as he can't stay alone. Any advice on what to do? I don't want any of my crabs to get hurt, the colony that i have is very peaceful.

[LadyJinglyJones]

Did you try dipping him in the fw dish before adding him back to the colony?

How does his agression manifest? What exactly is his behaviour towards other crabbos? A certain amount of dominance jockeying can be normal, as the crabs figure out their pecking order. Certain behaviours, like reaching into a shell, are bad news, but a bit of pushing isn't usually a problem.

[crabbykat]

He grabs them from behind and starts reaching into their shell and won't stop. He follows them around and shoves them out of the way when they are face to face. I think he is an alpha that is trying to be an alpha but I wonder if he needs his own colony? Does that sound accurate? Can he be introduced to other (new) crabs?

[LadyJinglyJones]

Ooh, yeah - that might not be great. Maybe we can figure out a way to get him to chill.

Quick questions, just to get an idea of your tat:
how many crabs?
what size is your tank?
how many hides do you have?
What proteins do you offer & how often?

Also @wodesorel or @GotButterflies, does that seem like it could be mating behaviour? I've only seen a couple of videos of mating/guarding.

[crabbykat]

I have him in a separate tank which is a 10 gallon tank, 1 hide, protein daily. I have 2 other colonies, 1 is a medium to large size crab colony with 9 crabs in a 55 gallon tank, several hides, daily protein, deep substrate, etc And a smaller size crab colony with 4 very smalls in a 10 gallon same set up. I want to reintroduce him into the 55 gallon tank. I have a play pen that I let the crabs out into in the evenings and that is where he interacts with them. He/She is a sand box bully.

Proteins I offer are: dried mealworms, frozen brine shrimp, boiled eggs and shells

[LadyJinglyJones]

Okay, if you haven't yet tried adding him to the 55 colony, perhaps that would be a good idea - he may react differently in a tank with hides & decor than he does in a more open setting (like the playpen - I sort of assume you mean a literal playpen?).

When an animal enters a space with other conspecifics, the space can provide as much context for how that animal behaves as the behaviour of it's peers does. Given a territory with desirable areas, foods, climbing apparatus and substrate, he may be less fixated on other crabs, though I'd still expect some posturing (pushing).

I'd first dip in the fresh water pool, then place him in the tank. I'd also try offering a novel food item or two - definately something with a strong smell, probably an animal protein like raw fish. They tend to be more attracted to foods they haven't recently eaten, so try that.

Then observe the crab with the others for as long as you can & decide if you like his behaviour better.

Edit- If he seems to guard the food options, I'd place multiple feeding stations in the tank to disperse the crabs' attention.

[crabbykat]

Ok, I can try to introduce him again to the 55 gallon tank. I did that previously and he chased them around but maybe I can get him/them used to it. Worth a try. My other option is to get him a couple of buddies for his tank and see if he can't make nice nice with them. Thanks for your responses!

[wodesorel]

It sounds territorial or like shell aggression to me.

I would do baths for all the crabs so they smell the same. That should prevent any back and forth squabbles. Smell is big to them and if they think they are from different colonies then they will get into it.

I would also check the shells you are offering against the preferred list. It could be your aggressive guy wants a new shell and likes what the others are wearing, and is in turn agitating them by his behavior. Giving him different options or letting him have access to your shell collection overnight might be enough to get him to settle down.

[crabbykat]

Ok, I can try the bathing. He has a bunch of shells in his tank but maybe he just wants what the other crab has. I will try to reintroduce him this weekend and see what happens. Thanks!