What can this critter be?

[Reefguide]

I about done cycling a 10g and have noticed from about day 1 than something oddd id happening. I have just one pretty big chunk of LR. The rock has a tunnel from the front near the sand line to the top. There is a pile of sand in freont of the opening at the sand line that keep getting bigger. Obviously something is pushing the sand out the opening. The odd thing is that I also from time to time see a cloud of sand being thrown out of the top opening. What could possibly throw sand out the top? Can seem to spot the culprit. Can crabs throw a pretty decent amount of sand around like that ?

 

[investigator1]

It's probably a mantis shrimp.

duhnt Duhnt DUHhhhhhhhhhhhhhh!!!!!!!!!!

 

[Reefguide]

I actually like mantis shrimps but the tank was intended to house a couple of very small juvinile clowns. That would be a problem !! Any other ideas? I'm dying to see something in there, but I dont want to dip the LR for fear of killing off bacteria on it or dusters, ect... any other Ideas on getting a look at the critter? Tried a air line and blowing air into the rock and nothing...

 

[fishfanatic2]

I think it is definitely a mantis. They have a habit of enlarging their tunnels and rearranging them. To get a look, tie a piece of meat to a string and lure him out. Mantises can chuck a LOT of sand.

 

[Anonymous]

I think pistol shrimps burrow like that as well.

I suggest placing a chunk of shrimp in front of the hole and sitting back in front of the tank with a few beers, hopefully you can get a better view.