HELP!!!!!!!

[bottle of dees]

Please help,
about 3 months ago i bought 20 kilos of fiji liverock, everything was going well until recently i started to hear repeated clicking from my tank,usually when i clean the algi off the tank wall or just after i have fed my shrimps etc.Then a piece of liverock about the size of a chicken egg was dragged across the tank overnight.
The next day i moved the rock back to its origional place, that night it was moved back again. Is this typical behaviour of a mantis shrimp or could it be something else.Over the last 2 months i have lost 2 hermit crabs but i put it down to my 2 cleaner shrimps getting hungry or could it be a mantis shrimp ? any imput would be very useful. If you think it is a mantis could you please advise on how to get it out of my tank without ruining my rockwork

kind regards Bottle of dees

 

[Navarre]

OK dont panic.

I had a similar situation as you last year but it was not what i feared.

People asked me if the clicking was rndom or was it able to click in rapid suession. I was told that if it was not rapid clicking then its a pistol Shrimp. If its rapid then probably a Mantis.

Months went past without any deaths but still the annoying clicking. After searching and searching i could not find its hiding place. Then one day asi was adding a new coral, i felt a clicking sort of virbratio next ot my thumb... Amazing! i found a tiny hole where it was hiding .. right next to my thumb!

Now i had isolated the rock it was in i watched to see what it was. It turned out to be a tiny harmless Pistol Shrimp. I still have it although i have not seen it since.

I would say that first of all you will need to find the hole its hiding in. This will not be easy and you will probably find it by chance.. or perhaps never.
You could try trapping it after the lights go out. If its a mantis though i would say that its far too clever to be caught in a bottle/trap.

Its possible that it killed some hermits, but to be honest hermits can fight among themselves also.

If you try a late nght vigil on the tank with a red torch. This might show the culprit up. Red torches or lights are good for watching at night as most creatures in the marine world cannot see the red light spectrum.

 

[bottle of dees]

Again last night i moved the piece of liverock back to its origional place,this morning it had been moved again ,is this behaviour of a pistol or the dreaded mantis?

 

[Navarre]

Cant be sure to be honest. Both tend to burrow and over things around. Possibly the Mantis will be more active though.
If the mantis (possible) loves this bit of rock that much then how about setting a trap? Place the rock in a reversed neck bottle and place the bottle where the rock is kept. Maybe the shrimp will fall for it (they are very intelligent though so it might take a few days.. perhaps more)