Something more sinister?

[tobrien]

Hi all,

This is my first post so forgive me if its in the wrong forum,

I have a strange problem with my tank, its been running now for over a year, parameters are near perfect, but for some unkown reason, my healthy fish keep dissapearing at night. The only fish who have survived since i bought my tank are my two ocellaris clowns. And i believe they are only still alive due to the protection of the green carpet anemone that they sleep in at night...

recently I lost my sailfin tang who was suffering from a mild case of fin rot which i was treating with melafix. And last night my small yellow bellied damsel dissapeared which was my most lively fish. in the past few months I have also gone through a coral goby and a jewelled blenny. My spotted Hawkfish is also looking very stressed and has been hiding behind some live rock for the past three days. repirating quickly.

I know that there is a bristle worm in my tank that could be close to 6-7inches long! Could it be the problem here? I never find any trace of dead fish when they go so something is up. Sometimes i also hear what sounds like a pistol shrimp every now and then too.

At the moment i only have my two clowns, hawkfish, yellow bellied damsel and a six-lined wrasse.

Any help or advice would greatly be appreciated

[twisted]

There could b quite a few reasons to lose your fish
One thing I experience was that fish that disappeared im my tank were eaten by a rose bubble tip I use to have. I'm sure as ppl chime in they will b curious as to what your params are so if you can post them, it will save us one question. most bristles r scavengers but in the world of reefing anything is possible

[leebca]

You really haven't provided much information about your tank/system. The 'fin rot' problem is indicative of a potential water quality problem, despite you saying that 'parameters are near perfecct.'

Small (under 3") bristle worms are very useful substrate stirrers. However the large ones can and do become problematic. They can and do attack fish when hungry enough and of course, the very large ones are usually very hungry. There are other possible predators that hunt at night when fishes tend to be 'asleep' in their hideyholes.

At about 2 a.m. some night, sneak up on your tank and look closely without useing lights and see if you see anything 'unexpected.' Then shine a dim light into the tank and search around for anything unusual. Do this a few times over the next few days and at different times during the black of night.

If you find or suspect a predator, hunti it down and remove it. Regarding Melafix, be sure to read this post: Melafix and Pimafix - How They Work and Don't Work

[Original Fin]

At about 2 a.m. some night, sneak up on your tank and look closely without useing lights and see if you see anything 'unexpected.' Then shine a dim light into the tank and search around for anything unusual. Do this a few times over the next few days and at different times during the black of night.

Just wanted to add that you can use a red filter lens on your flashlight. The red spectrum is easy for you to see, but it's difficult to sense for most marine life in your tank. I've been able to catch worms unawares with this method. They just keep doing their thing as long as you keep the light still. Use a white light and they get scared.

[leebca]

That's a great idea. Never thought of that!

[FoMoCo Master Tech]

Sometimes i also hear what sounds like a pistol shrimp every now and then too.

Are you hearing a clicking sound? If so, it's also possible it could be a mantis shrimp, FWIW.

[Reefing Madness]

And how big is your Carpet Anemone? I'm suprised your clown fish are still there. He must be big.