Knock Knock who is in my tank???

[xxnonamexx]

I have a weird thing going on in my tank I have a 55gal. 260Watt CoralLife Power Compact, 3 1W Lunar Lights, Live sand 4in DSB, 75lbs. Live Rock, 2 Cinnamon Clownfish, Firefish, Magenta Dottyback, snails, crabs, Feather Duster, Sabae Purple Tipped Anenome, 1 White Leather Coral, Red Sun polyp, assorted polyps, 2 Assorted Color Plate Corals, Pipe Organ, Frogspawn, Fox Coral, Flat Brain, Finger Leather, Mushrooms, Green Star Polyps, 2 8" Maxima Clams, Wet/Dry filter, Protein Skimmer, Heater I hear a weird knocking sound that I can't pinpoint. I know it isn't a mantis shrimp I orderned from LiveRocks to add a lil more rock and they searched my rocks for any and told me to test the rock in a quarantine tank to make sure no mantis shrimp and I tested and there was none. The rock has been in about 2 months and tank set up over 3 years. I bought corals recently but I heard if it was a mantis it would have eaten my 2 clams by now and the clams are just fine. It's a weird knocking sound happens once in a while I tried to pinpoint and so far think its from inside the tank. I can't figure it out. Any Ideas?? Thanks

 

[malkore]

could be a pistol shrimp. I believe they are reef safe, may even benefit the system. (feel free to correct me if I'm wrong though)

 

[Gatorfreak]

Do the knock/click sounds come in pairs (knock,knock) or one at a time. Pairs = most likely Mantis. Single = most likely Pistol. Mantis can, and often do, go undetected for many months.

 

[xxnonamexx]

If it is a Mantis I heard that It's good bye to my clams? How can I get it out or trap it? The sound is like a knock..........................................knock..knock.............................knock it fluctuats

 

[badfish]

how loud is the knock, like you think someone is at your front door. I have had my rock in for around two months now and just started hearing a clicking, most of the time its one click, like a snapple bottle cap can make, not as loud. As for a trap you can either buy one or make one. To make one cut off the end of a soda bottle (the part where the soda comes out) flip it around inside out so it creates a funnel into the bottle, place a raw shrimp in the bottom of the bottle with something that will hold it down. Lean it up against the rock you think its in. I used a 1 liter bottle on my friends tank to try and catch his mantis, but we caught his cleaner and three hermits the first time. I am almost positive that he has a mantis, and he has had no deaths, ive hear LR.com mantis are more docile, and often wont eat your livestock. The soda bottle trick takes a couple of nights from what i heard. Let us know how everything works out.

- Jeff