Murder in my tank! Please help!

[ntropics]

Here is what's been happening. I lost a Black spot butterfly about a week ago. He tended to hang out in the corner, and I just figured he wasn't well, and died. But then three days ago, my tassle butterfly was killed. He had bite marks on him, and was alive, but did not survive. Today, I lost a dartfish, again, with bite marks on him. THese could have happened after he died, but I am not so sure. Three healthy fish dying in two weeks?
Tank parameters are Ammonia, and Nitrite both zero. Nitrates about 20 to 30. (Testing kit goes from 20 to 40). pH 8.0 yesterday morning. Sg 1.025. (200 gallon ten feet long by 2 feet high tank)

My remaining fish are: in order of adding them to the tank over the past two years:
Lemon butterfly (5"),
Naso tang, 6inches long
flasher wrasse (3")
a coral beauty, bicolor and ferrugata (rusty) angel fish
a pair of false percula clowns,
Majestic angel (3")
falcula,(6") semilarvatus (5") and auriga (3") butterfly.

For various reasons not relevant, there is no possibility of a mantis shrimp in there hiding.

The only aggressive activity I have seen is the auriga nipping at the tassles on the file fish, and the majestic rarely chasing the bicolor.

Does anyone have any idea which fish might be the culprit? Or any other ideas?
Thanks for any help you can give.
Bruce

 

[Recty]

How big are the bite marks? Are the fins tattered and torn on the dead fish or is it just the body getting damaged?

No slices on the fish? Just bites?

You should be able to judge the size of the bite marks and pair them up with a fish.

 

[ntropics]

On the tassle they were tattered. The bites seemed a bit too big for a butterfly mouth to get to but I did see the auriga nipping at the tassle. No slices, just bites. I am leaning toward the majestic angel, but I just don't know. The only good news is that the more aggressive fish are the ones that are left (except maybe the clowns.)

Bruce

 

[snorvich]

How large are the clownfish? How aggressive? Mating?

 

[DoubleM 10]

just out of curiosity how do you know you did not get some sort of hitchiker(i.e. mantis or something to that affect)? how did you rule that out?

what are the inverts you have in the tank?

i think we would need to know all living things in their?

 

[snorvich]

Yes, other living things would be beneficial.

 

[ntropics]

I have two small hermit crabs, and a couple of snails and one cleaner shrimp. Also one slightly larger hermit (about one inch body) that's been there for over one year and never attacked any fish.
I am pretty sure of no mantis shrimp because when I first got the tank, I had a complete die back and recycle (two years ago) where everything (and I do mean everything) died, except for the hermits. I lost all of the snails, all the fish and the mushrooms (due to "precycled" live rock). I took in only a few mushrooms and a couple of favia since then. I suppose it is possible there is a mantis in there, but I just don't think it likely. I haven't added anything in over four months, other than the fish. In over two years I have seen only small asterias starfish as hitchhikers.

Bruce

 

[chjay00]

I think it is your butterflies. You have too many with simular shape and color. The most I was about to have was two b'fly in my 180. Anytime when I tried to add a third b'fly, it would be chased by the establish butterflies.

Were the Black spot butterfly and tassel butterfly recently added to your tank?

 

[ntropics]

It wasn't a tassle butterfly (don't know what that is!) It was a tassle filefish. So I lost a tassle filefish and a dart fish. The black spot butterfly was there before any of the others except the lemon and there was no aggression there. I am hoping this either ends, or I can figure out the culprit! (An "Aqua-Cam" might be of use here!)

Bruce

 

[DoubleM 10]

I think it is your butterflies. You have too many with simular shape and color. The most I was about to have was two b'fly in my 180. Anytime when I tried to add a third b'fly, it would be chased by the establish butterflies.

Were the Black spot butterfly and tassel butterfly recently added to your tank?

we are trying to help you.

why not take this butterfly statement into concideration.
it makes sence to me. my lions are the same way. i had the issue where one almost dies till my buddy let me borrow a small tank.

on the other hand have you sat and watched the fish for about 2 hours> maybe even more? when i sit and watch my tanks i learn alot about the peronality of the fish and their normal habits.

i would do that and see what you get.

 

[chjay00]

It wasn't a tassle butterfly (don't know what that is!) It was a tassle filefish.

LOL. I thought it was tassel filefish. But your first post had tassel butterfly. So I went with it.

 

[ntropics]

Ha Ha! Yeah, I just looked back at that! A tassle butterfly?! Anyway I have been watching which is why at first I thought it might be the auriga because he was nipping at the filefish. What I don't get is why too many similar butterflies would result in someone attacking the dartfish! Thanks so far.

Bruce