Is it a mantis or a pistol shrimp?

[asn]

For the past year plus, I have heard clicking coming from the corner of my tank. I have also noticed that the sand was slowly being taken from under some rocks on the right side side of my tank, and piled up around the rock, thus giving this creature more space for his home. As time went on, I had close to 3 inches of sand on the right side of my tank, when everything else had 3/4 of an inch. It always appeared as the door to this cave/home was towards the front of my tank.

Then a couple of weeks ago, I noticed a hole about 3/4 of an inch around in the back of my tank. This looked to be a new back door for this creature.

Because it appeared in the sand, I always thought it was a pistol shrimp, but today was looking at my tank, and noticed by the front door, something was fanning the sand out. It almost looked as if there was a power head blowing under the rock. I looked closer and saw a 2" long (dull) dark green/black shrimp of some sort. It didn't appear to have any sort of legs, so my thought was it could be a mantis, but it's face didn't appear to have long eyes like the mantis shrimp have. He did turn himself around, and kind of looked like a roly-poly. This also makes me think he's a mantis.

Does anyone know of a good way to figure out what type of shrimp it is?

Thanks!

 

[Gonodactylus]

The fanning behavior and jack-knife turn sounds like a stomatopod.

Roy

 

[dragonladylea]

My pistol does the same thing!

 

[Thurge]

lol and so on goes the debate as to wether you can distinguish a pistol and Mantis from each other without getting a good look at it. I would definately take Dr. Roy's annalysis to heart, but I think your going to have to get out the flash light and really pear into that hole and see what you can see.
Something else though, have you noticed a snail/hermit grave yard around the entrances to the burrow? Mantis are rather tidy critters and will dump the shells of food outside their burrow.

 

[dragonladylea]

If you are missing any small frags or mushrooms its a pretty good sign you have a pistol they like to "decorate" the inside of their burrows. I have had to pull all sorts of things out of the burrow. My pistol and I had a regular war going on over a Feather duster, I'd pull it out of the burrow and he'd pull it back in by the next day.

 

[Agu]

The behaviors of my n wennerae mantis and tiger pistol shrimp ( in different tanks of course) are completely different.

The fanning of substrate is completely unique to the mantis. The pistol shrimp is more like a bulldozer rearranging the substrate.

The mantis pics his lair and stays with it. The pistol is constantly opening and closing entrances to it's burrow, often with three or more entrances visible.

The only thing they have in common is that a piece of krill on a feeding stick brings them out of hiding :lol: .

 

[dragonladylea]

Agu - I have to disagree my Pistol is constantly "fanning" the sand
and has kept the same burrow for over six months. Yes I am sure its a Pistol.

 

[asn]

Well, I see several entrances to his home, and as of last night, he started closing up the one up front. I wonder if that means he's a pistol.

You also mention using Krill to bring him out. Do I used a freeze-dried piece, or do I buy something fresh or frozen?

thanks

 

[asn]

I caught a quick look at him again tonight. He appears to have legs like you'd see on a blood or cleaner shrimp. From the pictures I have seen, pistol's have legs, where the mantis do not. I am pretty sure it's a pistol.

 

[CraigsReef]

I am in the same boat as well, I've heard clicking sounds for more then a year now and just assumed it was my pistol shrimp i had. I also had a bunch of empty shells laying around the one side of the tank but again just figured my snails or hermits just passed on. I took a closer look this time at the shells and realized that i must have a mantis shrimp or either my pistol shrimp is snapping holes in these shells. Not quite sure how im gonna catch this guy. I just finished counting the number of shells laying around and to my surprise this guy owes me some cash.

 

[dragonladylea]

Craigsreef - dont blame the pistol to hastely, they like to collect things from all over the tank to "decorate" their burrows with, so he is probably collecting the empty shells and bringing them home. If you have hermit crabs in the tank they are more likely the culprits who owe you the money.

 

[Jakaru]

I'm not sure about other mantis shrimp but mine has dug through a rock and created about 6 entrences and exits that he can get to without leaving the rock. I can also spot him during the day peaking at me through one of these usually. You can try a 2 liter bottle trap. Cut the top off and invert it then stick it back in. Mantis seem pretty smart though and may find a way out of this but worth a try. I would put some krill or shrimp pellets in there and bury it partly in the sand near the entrace to see if it can be enticed out.

 

[CraigsReef]

Can pistol shrimp break the shells of snails and hermit crabs ?

 

[BigRedDog1934]

i have tampa bay saltwater and i am trying to figure out the same thing. i have had the clicking for about two months ( the same amount of time that i have had the rock) without seeing either a pistol or a matis. recently, however, i have found gorrilla crabs dead in the tank. they are white and lifeless but do not have any holes in their shells or look any different than they did alive except for the color difference. recently my cool little coral crab was found belly up and now i am thinking about getting into a real hunt.

does anyone know if there is some kind of "signature" to a crustacean killed by mantis? thanks in advance.

 

[Frostyeel]

Those gorrilla crabs sound like they are just molts, but it is very common to get mantises hitchhicking on tbs rocks, so it would be safe to assume you did.

 

[BigRedDog1934]

i think you are right about the molts. i just found my coral crab alive and well last night. i thought these things were dying; there just getting bigger.

i had two mantis in my first shipment from tbs. i got them out with the baster and the carbonated h2o. this one may be tougher because of the additional rock however. its kind of like counter insurgency.