Silent assassin... HELP!!

[soulbereaver]

Ok, so i have a 75 gallon tank, been set up for about a month. Have 60 lbs of live rock (was well established) and 20 lbs base.

Anyways, I have 3 Chromies, a couple mushrooms that came on the rocks, and an aptasia-like anenome that hasn't spread at all, and it's something to look at so I'm keeping it for now.

Two weeks into my tank being running, the anenome and mushrooms were growing and prospering. One day I woke up to see my anenome looking a bit chewed up!! Some of its tenticles were definately shrivled up at the ends, and appeared much shorter then i remember. It eventually recovered.

Then I bought 3 Chromies. Two weeks into having them (today) I woke up and one was dead, and another was badly hurt. The dead one had no visible wounds that I saw, but the hurt one had what looked like missing scales towards his tail, and damaged scales on both sides, torn fin, etc.

The wounded fish is doing ok atm, and one Chromie is just fine, but the third is a gonner and all three fish were just fine when I went to bed.

WHAT IS ATTACKING MY TANK?? What do i do about it? My rock has tons of large caves and pores, I'm thinking I'll never find this thing. First an anenome, and now my fish... I refuse to add anything else to the tank until I catch this preditor.

Any ideas??

[gimmic]

get a red filter and check your tank out at night

[woodiecrafts]

When you say well established rock, I am assuming you mean it came from another tank and not just bought online. In any case the first thing that comes to my mind would be either a
Mantis Shrimp or a Crab of some type. After you shut your lights out and when every thing is good and dark, take a flashlight and start looking around and see if you can spot one or the other.

[soulbereaver]

thank you I will definately do that. If i find something and want to remove it, what necessary precausions should i take when trying to remove it? What's the best way to remove something like that since I'm sure it will go back to hiding the minute it senses danger...

Also, I thought at one point that maybe the fish and the anenome could have gotten into a battle of some sort, but the anenome isn't any bigger that my chomies... that would be very unlikely right?

[Aerowen]

theres a bottle trap that you can make yourself or buy- just put some food in it and you should catch w/e is attacking your lifestock- maybe a mantis?

[soulbereaver]

I'm a diy kinda guy, do you have a link or something explaining how to make a bottle trap or any kind of trap to catch a mantis shrimp or crab or whatever this thing could be?

[otrlynn]

I believe that I have read about using a tall glass or bottle and baiting it w/a piece of seafood (clam, shrimp, etc) and propping it on an angle against something in the tank. The idea being that the mantis shrimp or whatever can climb/slide down into the glass but not back up the slippery side of the glass. My memory is fuzzy on this but at least this response will bump you back to the top and you may get better info from someone else.

[cgoodman381]

for your flashlight try a red baloon over the top.

[super stooge]

the trap should be in here somwhere :)

http://reefcentral.com/forums/showthread.php?s=&postid=6085950#post6085950

[WinnipegDragon]

Could be something like an Arrow Crab too?

[cgoodman381]

would an arrow crab tear something up like that? It could be a sally lightfoot, but I dont think you would miss it if it was walking around.

[Sk8r]

half litre wine carafe tilted up at 45 degrees so any intruder will be unable to climb out: raw shrimp bait at the bottom. Left overnight.