fish highly stressed, lethargic, drops to bottom

[lostanime]

The last week's been rough around the aquariums.

We just lost two more fish - I'm not sure how/why, hoping someone can point me in the right direction.

We've had the refugium cut off from the main tank as a quarantine (and would remove sand/chaeto and use as hospital tank if something came up) and had a small yellow tang in there.

I finally replaced the flame angel we re-homed with a "hybrid yellow fin nox" according to the LFS (although i'm pretty sure it was a moonbeam dwarf angel, perfectly matched pics/description)

The new dwarf went in quarantine with the yellow, but the yellow tried to harass him for nearly a day straight... they really needed to be separated. Since he looked plump and healthier then the new yellow (and because he wasn't a disease-magnet tang) I was more comfortable moving him to the main tank then the yellow. In hindsight I should have made a divider for the quarantine, but that didn't dawn on me at the time.

He was skittish and hid alot in the main tank (which I assumed was normal for a very dark colored fish normally found in rubble in the wild) and keening noted but didn't start stressing over him not eating much.

For the first 48 hours nothing changed. Then, the following morning my very large blonde naso tang started to look stressed (keeping up his "mohawk", darker then usual coloring) and was hiding under a cave... I threw in some frozen food and despite being one of the most active eaters he remained hidden. I threw in a new sheet of algae (which he always pursues and tries to keep from other fish)... but he ignored.

At this point, the gig was up, something was obviously wrong with the naso. I circled back to the dwarf angel who was also not eating, and lifted the branchrock he was hiding in and he fell out of it (I couldn't see that he had been laying in the rock, not swimming/hiding) He was alive but not for much longer.

The naso passed the same way... a few hours later he was on the bottom of the tank. A few hours after that he was on his side on the bottom of the tank. After that, I euthanized him because he wasn't able to keep invertibrates off of him (he didn't even react when i reached in and touched him w/ rubber gloves on)

I understand that I probably introduced something to the main tank with the dwarf angel, but I have never seen a healthy (not to mention large) fish pass so quickly.

One of the naso's eyes had a scratch on it, but he otherwise appeared mostly unscathed. Neither fish had any noticable abnormal markings or signs on them.

Water parameters - undetectable ammonia, nitrite, nitrate. Phosphates nearly undetectable. PH 8.2. Salinity 1.024. Temperature 79F.

I'm not aware of any shifts or swings in the tank. We've had the naso for quite a while - he was the largest fish in the tank. No other fish are showing signs yet.

I'm trying not to grieve over the fish yet, because for now I need to focus on doing what I can to save the rest of them.

Any insight would be much appreciated.

[Loman]

Wow - I am sorry to hear about these problems.

I really have no ideas to offer that your write up did not eliminate. As you know the water parameters and system is text book. I would expect most diseases to take a bit longer and to have some visible signs on the deceased fish. You might talk with the source of the hybrid yellow fin nox to see if they encountered any problems and what they did to solve them? The only other thoughts I have are, you may be in one of the rare situations where a shotgun approach is needed and try so general broad spectrum antibiotics. That may be hard to QT all the tank. Wish I could offer more help

[lostanime]

QT the whole tank would be surprisingly easy at this point (they should all fit in the 75 fine on a temporary basis, kept main tank stocked fairly low to begin with) I'll have to swing by the LFS I acquired the nox at and see what they can share. It's one of the best LFS (over 20yrs running, very clean, very high quality)...and the owner has been good friends with one of my older brothers (that was also into saltwater) since before he opened the store. I have alot of faith in the stores ethics and practices because of things I've seen up there. He even gives me full retail on fish I need to rehome and scolds me when I look at incompatible/inappropriate fish for my system - how cool is that for a LFS? I'll post what I can find out.

[lostanime]

Joe (owner of store) has no clue with the nox. He had the nox for nearly a month in his store, and gave him dips before adding him to inventory. He ate fine at store and was even mildly aggressive (harassing small blue hippo tangs)... he was shocked to discover that it never ate in my tank and passed within days. He ran a full battery of tests on my water to come to the same #s I got. He tried to give me store credit for the guy (I refused, not his fault and I'm not trying to take advantage of him)...but then he refused to charge me for the stuff I bought today. Talk about one dedicated owner.

He knew exactly what happened to the naso. He's a little more observant then I am - there was one very mildly swollen part down low ... he had a blockage, which according to Joe is the 2nd most common problem with tangs in captivity (the first being ich)... and that a tang will commonly die within a day from a complete blockage. For future reference... he mentioned it's not 100% safe (fish die as often as not) but very gently rubbing/massaging the abdomen from front of fish towards back will sometimes free up the blockage.

Talk about some &^%# luck. $300 worth of fish in a week all died from bizarre circumstances (mandarin jumped out of tank, very large blonde naso apparently had blockage, and nox hybrid apparently couldn't handle move to tank) If I had lost the most expensive fish in the tank as well as those guys, I probably would be taking a break from the hobby now.