arrow crab

Just noticed this appendage on my arrow crab. I have no idea if it is male or female. But I’m assuming male…. it won’t stop messing with this appendage (I’ve had teenage boys sooo that’s where my mind went ). Normal? Or is something wrong with it?

I made this account to ask if anyone has bred Arrow Crabs before? We had brittle stars, fire worms, tube worms, bristle worms as hitchhikers in the live rock but now there is hundreds of tiny things running all over. The arrow crabs had babies twice and is pregnant again. The tadpoles were...

Looking for an Arrow Crab. Wanting to take care of some Bristleworms before they get out of control.

Been working on getting a new IM Lagoon 25 tank setup which is currently cycling. So starting to get more serious about thoughts on stocking. The tank is mostly for my kids so they have requested a few of the options. Looking for advice on if this combo would work well and then in what order...

Hey y’all happy to finally join this killer forum !! Kind of a weird question, for anyone with a arrow crab, how responsive are they when you try to poke them or scare them with something.? Mine seems to be blind, only seems to move around with feel of touch. And if I put a feeding tube in front...