Holy Crap...What Is This?????

TAKE IT OUT. they can shatter glass tanks as adults but the big risk is losing ALL your livestock. they are the grim reaper of this hobby. Lightening fast and mean as hell. Their power is unmatched for their size. You can hear their strike through the water and glass, that is how powerful they are. They are not called thumb-splitters for nothing.

Biff is on the right track, take the whole rock out. BE CAREFUL and have a good first-aid kit near-by just in case. Good luck. I fear those things more than sharks!

You'll be lucky to get $5 for it at the LFS. They don't usually pay much for livestock.

If it was me:
I get it out and stick it into a 5g nano tank. Run a local add on Craigslist or in the local reef club forum. You could easily get $15 or $25 for it when selling direct to another reefer.
I'm just trying to figure out in my own mind how to approach this. So let me think out loud for a minute:

I guess I'll start at the top of the rockwork and place all of it at the other end of the tank. I have an idea of where he's made his home but not totally sure with rock or which specific location. If he's holes up in a rock I've heard that soda water or a blast of regular water should get him moving pretty quickly.

I wonder if he'll try to move around and hide from me when he realized he's being targeted. Or will he simply stick to the home he's made for himself?

How should I catch him? Should I try to suck him up with something? Nets? And once I get him what should I put him in? Perhaps a rubbermaid container for food would be the best.
you can keep him short term in a rubbermaid container (meaning a month) with a powerhead, heater and some rock.

Here is my solution for catching small undesirables. I just had to use such a trick for my Keyhole angel. First, you need to section off your rock near, but not on top of where he hides. move half the rock to one side of the tank to create enough space to slide a sheet of plexiglass the width and height of your tank. make sure the sides are flush with the tank walls or he will be able to scoot through and you have to start all over again. once the plexiglass barrier is set, start removing pieces of rock to the other side of the tank. have the net ready for when he shoots out. keep removing rock until you get to his or you see him, nab him and viola!!! No more Mantis Shrimp

BTW, when you take this approach, prepare to get you, your clothes and the floor pretty wet. You will also need about an hour to catch him and another hour to return the aquascaping to where you want it. It you have livestock try and "shoo" them to the other side of the tank from where you are working, it will help them be less stressed.

Before you do anything,postively identify the rock your mantis is in.DONT do anything untill you have completed that step.They can get theirselves into some tight places and you may move the wrong rock without knowing it.
once you have his rock identified,then carefully remove THAT rock.You'll have to get a net big enough for the rock to fit in but with small enough mesh to keep the shrimp from escaping.
Forget the first-aid kit.If he hits you,your gonna need stitches.
Good luck getting em.
Just a little update:

I spent about 45 minutes hunting for the little Bastard to no avail. I did manage to rearrange my rockwork though and was quite please with myself with the exception of that lingering mantis shrimp somewhere in the tank.

I fixed myself a rum n' coke and sat back to enjoy the new scenery when lo and behold........THERE HE IS! Coming out of a rock I placed at the front on the bottom only covered by one other large rock.

I didn't take any chances. I went in for the kill with my tongs. I took both rocks out and put them in my sink and totally submerged them in scorching hot water. It's been about 5 minutes so far and I can't seem to shake him out of the rocks. He's gotta be dead, that's if he didn't jump ship and take off to another rock.

So, as I have no experience at this and I don't have confirmation that he's dead in the rocks I took out does anyone know how likely it would be that he took off and relocated?
Put those 2 rocks in hot water and leave them sit overnight. You've already killed any other invertebrates anyway, so be sure you killed HIM. Maybe even put those rocks in a kettle of water and boil them?

I'd leave those 2 rocks out of the tank for about a week and see if you can spot him in the tank--just in case he did make a run for it and managed to escape.

We may have to start referring to you as Yote 2. You a killa!! :chair:
Hahaha, thanks RC. I like my reef tank, no, I love my reef tank! I don't want this f%ckwad messing everything up for me. Lol. Maybe the mantis will drop out of the rocks overnight or in the next few days or something. Other than that I guess I'll just have to keep a lookout for him. Much bigger than I last saw him when I took that photo. But, he was poking his head out getting ready to attack my flame angel for getting too close.
I am most likely getting a 3" mantis for my nano this weekend...he will be by himself.. cept for his prey that is......:evil!?!?:
ya, i saw that other post. nice job on the freebie. i'd like to have one, beautiful creatures they are, just not in my reef tank. i saw the photo. be sure to give us a feeding vid when you get him.
Newport I hate to tell you this.But that mantis has a 75% chance that he got away.
There probably one of the fastest critters on the reef.Worse than damsels.
I buddy of mine bought one of those mantis trap.Stick food in and drop it near its lair.It actually worked and this way you can still keep it in its own dedicated tank or in the refugium.
Here's a myth,
There are only a few species thats considered thumb splitters,tank breakers and fish killers.The majority of them stay tiny and scavenge.
I buddy of mine bought one of those mantis trap.Stick food in and drop it near its lair.It actually worked and this way you can still keep it in its own dedicated tank or in the refugium.

Thanks Reef, where do I buy a MantisTrap??? Or do I have to fashion one myself??? :frustrat:
Had a mantis in my tank not too long ago. HAD. I took my time with it. I waited until I was sure of which rock he was in. Just happened to be looking at my tank when I saw him, just like you, pulled out the rock in a bucket of hot water and out he came. Rock goes back in, mantis doesn't. It was pretty simple once you find out where he is. If he hasn't come out by now, assume he escaped.