Fish deaths...

[Mihai]

Something must be out of whack in my system and I don't know what...

I have a nice, 90gal with lots of SPS and LPS being perfectly happy and just a few fish (1 yellow tang, 2 mandarins, 1 chromis, 1 royal gramma, 2 clowns).

While being on vacation for one month my yellow tang died without apparent reason: the neighbor told me that one day was fine, and the other one was hanging in a corner looking bad, then it died. Despite putting him in a freezer bag and in the freezer I couldn't figure out what was wrong with him: he was nice and plump like always. I classified it as an inevitable vacation loss.

After returning from vacation (Aug. 2nd), I noticed that all my corals looked GREAT, with huge growth. I attributted this either to my increased Alk/Ca additions or to the large (40 gal) water change afforded by the new sump just before I left.

However, last night I noticed that my male mandarin looks VERY bad: his lateral fins (the nice thin - blue ones) were almost gone - only the bones were sticking out. As a result he flopped them very fast to hover as usual. His back fin also looked pretty bad.

In contrast, the female mandarin looks perfect. I asked my neighbor about cleaning the glass of my lamps (as I suspected UV damage), but she said she never did it.

Today I was unable to find the mandarin, I hope it's in the rockwork rather than dead.

I'm stumped... any ideas what can it be? Again, all the other fish look and behave normally, all corals (acros, monti, zoas, mushrooms, acan, frogspawn, etc) are fine, actually look better then ever.

What should I test? (temp and salinity are on par).
Mihai

 

[Anonymous]

Well this may or may not have anything to do with your losses, but here goes. A buddy of mine had the unfortunate experience of having someone's kid dump a bowl of dogfood in his tank one evening. The result visually was exactly what you might imagine, but also some great looking corals, all polyped out and happy, and 12 dead fish due to the ammonia/nitrogen/Ph spike.

This problem may be unrelated to your losses, but just thought I'd throw it out there. Check your skimmer...

Other than that, there are a myriad of things that can wack a fish...for all you know your Tang had a brain tumor or fatty growth around the kidnies that finally got him.

Having said that, my feeling is - Vacation + neighbor feeding + Murphy's Law = Spike

Jim

 

[Mihai]

It turns out that my skimmer was indeed off (air intake tube under water). However, I think that it's been off only for 1-2 days, as a couple of days ago was skimming happily. So... can this lead to an ammonia spike? That fast? And doeas an amonia spike can do fin damage to a mandarin (and not the other one)!? The lady (and all others) seems to be fine.

Any other ideas?

M.

 

[Anonymous]

The skimmer turned off would decrease O2 in the tank. This could have killed the Tang, as they need lots of 02.

As for the mandarin...how long have the 2 been together? It's possible that one is picking on the other.

 

[Mihai]

When the tang died the skimmer was working (he looked bad for about two days in a row - with O2 will be only the night).

Regarding the mandarins, they have been a couple at least from March. I'm sure they are a pair. And even if they were not, the big one was the one with the problem. Nobody picked on him...

Last night I checked Alk, Ca, Mg, all are normal.

Mihai

 

[Anonymous]

There maybe some sort of predator in the tank attacking your fish. A small crab or mantis could be in there and is now just big enough to do damage. Either that, or your tank has something bacterial going on, causing fish to die and fins to rot.

 

[Mihai]

There IS a small crab in the tank. I seldom (say twice a year) see a crab that looks exactly like an emerald crab but with dark shell (black and brown feet). The claws and feeding habits are similar to emerald. I never had the oportunity to capture it, I barely see it somewhere deep in the rockwork from time to time.

However, the tang had absolutely no signs of external damage and the madarin was not "chewed" anywhere - just the fins. There are also lots of small snails and blue-legged hermit crabs that would make much easier meals than a yellow tang.

Regarding the mantis, I'm pretty sure I don't have one (the tank is 2.5 years old).

But the bacterial thought is scary... can I do anything about it? Don't say antibiotics as I don't believe in them .

Mihai

 

[Anonymous]

Anti-biotics could kill your coral so don't go there.

 

[Anonymous]

Unless you have a QT you cannot use antibiotics.

The crab maybe the answer to your mandarins injuries. They tend to attack when the fish "sleep".

 

[Anonymous]

sorry to hear that Mihai...I've got nothing constructive to add, except to ask how is the mandarin doing?

 

[Mihai]

He's doing bad. And it's not the crab - its a bacteria or something. My wife told me that she saw him on the bottom last night. His pectoral fins were also attacked - she described it like having lots of salt crystals - like the rim of a margarita glass. She said that it was moving slowly but not swiming or eating.

The only thing that gives me some hope is that he's a big guy that was quite fat when this happened, so, if needed, he may be able to go without eating for a couple of weeks until he gets airborne again after he gets rid of whatever got him. That is if he can fight it off - from what my wife said, it seems that he's not very effective at this time.

If I can catch him, I'll try to put it in a hospital tank with antibiotics. One thing to notice is that there had been no new additions to the tank in many many months (perhaps March when the lady came) so it's unlikely that it's a parasite. It must be a bacteria...

M.

 

[Anonymous]

Hopefully you can catch him and try treating it.

Good luck...

 

[Mihai]

I'm happy to report that it looks like he's going to pull through. He seems to be recovering at this point. He started eating again a few days ago and the skin on his fins started to grow back. It's still a long way from getting back, but he's eating and recovering (and doesn't seem to be slimmer than before).

Just wanted to let you know,
M.