Unknown Tunnel Maker

[crazyhaggis]

I’m having a strange problem if it is a problem. The rocks on the right hand side of my tank keep getting under-mined. It is although something is making tunnels under them. Over time this causes my rocks to collapse. I’ve noticed sometimes some of the tunnel’s ‘entrances’ are blocked with shells. During the day my Skunk shrimp likes to hang around this side of the tank, alhtough I've never seen her tunneling. When I check the tank at night I find her hiding behind the rocks on the left side of the tank.

Does anyone have any idea what could be making the tunnels, should I be worried about it and is there anything I can do to prevent rock falls?

[crazyhaggis]

Just thought I'd add I have the following fish:
2 tomato clowns, a sergent major and a blue damselfish.

[Ace25]

Damsels can dig holes.. seen that many times with the blue damsel. I would guess that is your culprit.

[Mustang Boy]

you may have a mantis shrimp in your tank it couldve come with your live rock as a hitchhiker and i know there are species that tunnel in the sand

[manowar669]

pistol or mantis shrimp. The shells around the entrance seem like the behavior of my mantis and pistol shrimp (different tanks). they like to re-arrange the furniture.

[Fishieness]

pistol or mantis shrimp. The shells around the entrance seem like the behavior of my mantis and pistol shrimp (different tanks). they like to re-arrange the furniture.

that would be my guess too.

[crazyhaggis]

Is there anything I can do to help me figure out who's making the tunnels?

[Ace25]

Are you hearing any strange noises coming from your tank that you can't figure out? Like "clicking" or the sound of a small tree branch snapping? Those would be the best indicator that you have something like a Mantis/Pistol shrimp in there.

While it is common for the blue damsels to dig holes, it is not common for that fish to stack shells/rocks outside the hole. That is definately a trait of shrimp and jawfish.

[Arakkis]

Sounds like a pistol shrimp to me

[kcress]

Yes. Fill in the holes, then lay-in-wait after the lights go out. You will probably see the perpetrator..

[Mustang Boy]

i would listen for a clicking noise that will narrow it down and since your skunk shrimp is still alive i would think it isnt a mantis unless it is a spearer

and if you do hear a clicking if it is random it is most likely a mantis whereas pistols have a series of clicks they do

[Ace25]

I think you got that backwards.. mantis make the clicking sound, pistols make the random "snap". I had a pistol that lived for over 4 years.. it would "snap" about once an hour or so and never snapped more than once at a time unless the cleaner shrimp got to close. For all the years I had both in the same 29G tank (cleaner 5+ years/Pistol 4+ years) the pistol never harmed the cleaner which I found odd, it definately would snap at it, just never hurt/stunned it.

[Mustang Boy]

oohh i must have my information mixed up i thought i had read somewhere that pistols made a clicking(or snapping pretty similar) noise more than once in a row somewhat rhythmically whereas mantis clicks are more random

[got2envy]

My pistol very seldomley makes any noise...I do see alot of empty snail shells around his area and the sand is piled high, also one of my cleaners came up missing last week without a sign..was in there for a year :( my other shrimp looks bored haha
they love to tunnel under rocks so at night with a flashlight you will be able to see him..if it is a pistol and not a mantis...mantis like holes in the rock

[gomrjoe]

Have you noticed that your hermit crab population is slowly shrinking? That could be another sign... pistols and mantis love to feast on hermit crabs. I had a pistol in my tank for over a year, I fed him for a while, then got tired of cleaning up his mess (colapsed rocks), and he was feasting on my cleanup crew. I finally wanted to reorganize my tank and I pulled the rocks out and grabbed him.

If it is a pistol they are tricky to catch, the traps don't work that well on them because they are practically blind. As I said, I wound up having to remove most of my rock.

[kay-bee]

Damsels can dig holes.. seen that many times with the blue damsel. I would guess that is your culprit.

Yep. I've got one doing that in my tank (have caught it in the act fanning its tail and creating fist-sized pit between one of my stony corals and live rock.

I've got a maroon clown in another tank which has escavated the sand down to the glass (creating a 5" deep mound of sand in one of the tank corners).

You've got a lot of culprits in your tank.

[crazyhaggis]

ok everyone I've 'filled' in the entrance I'll let you know what I find