Catching Mantis

[dmitry]

I think I have a hitchiker Mantis in my tank. Just a few weeks ago I upgraded to a bigger tank (72 from a 29) and added a lot of live rock. Over the last two weeks 6 fish have vanished without a trace. I suspect a Mantis because the readings are fine with only Nitrates a tad high. I have neither seen it nor heard it in the tank - just the disappearing fish suggest something, ahem, fishy is going on. As I was putting the rocks into the tank I was sort of looking at them (though not looking for a Mantis, of course), flipping around to see what he best way to put them may be. Never saw any sign of a Mantis. (Though I did see the two Emerald Crabs I hadn't seen in weeks.) And then my poor little fishies start disappearing; it's like "And Then There Were None" in there. I wonder how big a Mantis would have to be to kill and consume six fish (2-3 inches each) in two weeks. And could I have missed him in the rocks?
And the biggest question: how can I catch him?? There are the plastic bottle traps, which I've tried for several days without much luck. The idea of taking apart my rock-work is not an attractive one!!! Anything else I could try?? :help:

 

[celacanthr]

have you looked into your tank at night with a flashlight?
try that and if you see the mantis shrimp watch where he hides at and quickly dump that rock into a prepared container full of either ro water or a hyposaline solution. The mantis shrimp should come out fairly quickly when he does quickly, safely grab the rock and pull it out.

 

[bret61081]

throw a raw shrimp in at night wit hthe lights off...get a blue led or dim flash light...he should come out...thats how I found the 3 I had...

 

[dmitry]

I've got moon-lights. Will they do for viewing? So far all the attacks have taken place while the moon-lights were on...so probably. I'll have to throw in some fresh meat. I was using some raw salmon for bait in the trap. Would a piece of that do? I just hope it's not one of the rocks on the bottom, you know?! Ugh. You had three? Sheesh!

 

[dmitry]

I did a few hours' worth of night vigil last night with a different kind of trap. I took some of that window screen net and attached threads to the corners and sawed a piece of raw salmon in the middle. The thinking was that if this %^#^%$%&^ comes up to eat it won't be able to grab the piece and run, but I'd try to pull the net out with it in it.

Didn't work, though. Saw nothing, heard nothing strange. All I caught was a nassirius snail. I'll try again tonight with a raw shrimp.

 

[celacanthr]

i wish you luck!

:happyfish

 

[sw65galma]

If it is a mantis, would you send it to me?

 

[dmitry]

You wanna come over and help me find him???

I'm rather freaked out by the whole thing, to be honest.
The more I talk to some people the more they raise my doubts that it is a mantis considering I haven't seen him. And some have even raised doubts that a mantis could eat six fish in two weeks unless it was a really large one... in which case I'd definitely see him! So...I'm all confused. My overnight trap managed to trap 9 nassirius snails who went berserk for a raw shrimp in there. Some job I had getting them all out of there when I came home at 3:30am!

We'll see what happens. I wish I'd just see one in there and know that that's what I'm dealing with instead of this great unknown. And the idea of taking apart my rockwork because I *think* there's a mantis in there is just silly! :notsure:

 

[dmitry]

I discovered something interesting today. One of my power-heads wasn't working, but plugged in. The problem was that the in-take nozzle was turned too far to the side and had become disconnected from the body of the pump... I assume this thing was leaking a lot of electricity into the tank??? (It worked fine once I reattached everything.)

 

[dmitry]

Well...the last of the Chromises disappeared since yesterday. So...I guess I'll breaking the rocks down after all.

Though an hour long vigil last night didn't reveal anything.

So...how high should the salt levels be to dunk the rocks into? I don't want to kill off any bacteria/crustaceans on it.

 

[sw65galma]

Originally Posted by Dmitry
I discovered something interesting today. One of my power-heads wasn't working, but plugged in. The problem was that the in-take nozzle was turned too far to the side and had become disconnected from the body of the pump... I assume this thing was leaking a lot of electricity into the tank??? (It worked fine once I reattached everything.)
No that shouldn't cause any stray voltage.
The rule of thumb is that if anything leaks voltage into you tank for ANY reason THROW IT AWAY! It's NO GOOD and you can't fix it.

 

[sw65galma]

Originally Posted by Dmitry
Well...the last of the Chromises disappeared since yesterday. So...I guess I'll breaking the rocks down after all.

Though an hour long vigil last night didn't reveal anything.

So...how high should the salt levels be to dunk the rocks into? I don't want to kill off any bacteria/crustaceans on it.
I'd just put it in a tub with food far awy from the rock and watch...u see anything run out, grab the rock.

 

[dmitry]

I don't have a tub big enough for 100lbs of live rock!

Since I haven't actually seen any Mantis in the tank I don't know what rock it's in...or if it's even in there at all! I keep flip-flopping on what I think is going on, but just to be safe I'll have to pull all my rock out and check the rocks out one by one. (That's going to suck!) If no mantis...try to figure out what else is killing my fish. But I wonder just how salty that water should be. What levels??

 

[cam78]

Whatever happened?