Two PBTs die virtually overnight - rest of fish are fine - what's the deal? No ich, no velvet.

[merkmerk73]

Hey folks,

About 3 weeks ago I picked up a PBT and acclimated it along with my yellow tang and kole tang.

Everyone got along fine as the PBT was newer. PBT started going after Nori and would eat mysis/brine on occasion as well when the rest of the fish were fine.

Minor fin damage in first 48 hours from clownfish, after that healed up and everything looked good for 2 weeks.

Then it went from healthy to hiding and dying in a 36 hour period. No signs of ich or velvet.

So I chalked it up to bad luck, got another one from the store, and within 48 hours it went the same way - reclusive behavior, then rapid breathing and flop over on side and die. Again, no ich or velvet.

What's going on? I know PBTs are ich magnets, but I've never seen a fish die from ich or velvet and show zero signs on the body - if they die from ich/velvet it's all over the body.

Additionally there has been no physical damage to the fish until it already starts acting sick (at which point other critters seem to take advantage) - and I've never seen a fish take a minor nip and die in 36 hours from it.

Tank is about 2 years old
Salinity 1.0265 (a little higher than I like)
Phosphates .1
Nitrates 5
Mag about 1300
Calcium about 440
Alkalinity 8.6

Photo info:

Fish in box is 2nd PBT that was fine and then rapidly declined and died within a few hours

Fish in net and swimming was eating and thriving for about 3 weeks and then rapidly declined and died within 24 hours.

He was always a little skinny.

Fin damage didn't show up until fish was discovered to be weak and sulking - I do not believe a fish of this size keels over and dies from minor nips and he was fine when active and swimming so I am not inclined to believe these are tang bullying deaths

Tagging #fishmedic

 

[threebuoys]

I'm concerned the first PBT may have been malnourished unless he was ravenous during the two weeks you had him. The frozen cubes of mysis are 90% water.

For the second PBT, did you check the salinity of the water in the bag with the fish when you got him? Some vendors run tanks well below 1.026 and fish must be acclimated over several days to avoid shock. The picture of the PBT out of water seems to confirm a malnourished condition.

 

[merkmerk73]

I was worried about the first one too - he was skinny when I got him and never really fattened up. But my biota yellow tang was kinda scrawny too and fattened up like a hoss.

I fed nori 2-3x a day and he went after it and only occasionally went for mysis/spirulina brine. (on the spirulina brine it seems to be some kind of coloring and I question the gut loading but that's a different topic!)

He was great for 3 weeks - I was cocky and thought I had acclimated another tricky fish through good husbandry, then it just got sick and died - I took a video last saturday of it swimming around and eating and then monday morning it's dead.

To your question yes I did a pseudo drip acclimation where I put the fish into its water, then drained half and filled half with my water, and did that every 15-20 minutes until it was good to go and released into the box for the night.

In both cases I kept in an acclimation box for one night and then released into the DT after no aggression was shown (they don't seem to eat in the acclimation box so I wanted it out and about asap)

 

[threebuoys]

I was worried about the first one too - he was skinny when I got him and never really fattened up. But my biota yellow tang was kinda scrawny too and fattened up like a hoss.

I fed nori 2-3x a day and he went after it and only occasionally went for mysis/spirulina brine. (on the spirulina brine it seems to be some kind of coloring and I question the gut loading but that's a different topic!)

He was great for 3 weeks - I was cocky and thought I had acclimated another tricky fish through good husbandry, then it just got sick and died - I took a video last saturday of it swimming around and eating and then monday morning it's dead.

To your question yes I did a pseudo drip acclimation where I put the fish into its water, then drained half and filled half with my water, and did that every 15-20 minutes until it was good to go and released into the box for the night.

In both cases I kept in an acclimation box for one night and then released into the DT after no aggression was shown (they don't seem to eat in the acclimation box so I wanted it out and about asap)

If the salinity of the water from the fish store was in the 1.019 - 1.021 range, drip acclimation will not work very well to raise the level slowly to 1.026. You would need to acclimate over 2 days. Some mail order vendors ship at the lower salinity level. LFS vary from one to another. Some fish species are affected more than others, but this is a potential issue.

 

[merkmerk73]

If the salinity of the water from the fish store was in the 1.019 - 1.021 range, drip acclimation will not work very well to raise the level slowly to 1.026. You would need to acclimate over 2 days. Some mail order vendors ship at the lower salinity level. LFS vary from one to another. Some fish species are affected more than others, but this is a potential issue.

I've never heard that it would take days and that hasn't been my experience

I also wouldn't expect it to take 2-3 weeks from poor salinity acclimation to result in a death.

What I am finding out is that PBTs just seem to be difficult to keep regardless of ich/velvet.

 

[merkmerk73]

The more I read the more I find people pointing at velvet.

I've never encountered any fish flashing or displaying any spots or dust on their bodies, which I thought was the hallmarket of velvet.

 

[Jay Hemdal]

The more I read the more I find people pointing at velvet.

I've never encountered any fish flashing or displaying any spots or dust on their bodies, which I thought was the hallmarket of velvet.

Dehydration from a salinity rise can cause a fish to become really thin. However, you’re correct in that this issues sorts itself out in 3 to 5 days - either the fish recovers or dies. I wish dealers wouldn’t sell fish at salinity - it causes a lot of issues when fish are then moved into full salinity.

I don’t think this is velvet - that is super contagious and very quick to kill.

 

[merkmerk73]

Dehydration from a salinity rise can cause a fish to become really thin. However, you’re correct in that this issues sorts itself out in 3 to 5 days - either the fish recovers or dies. I wish dealers wouldn’t sell fish at salinity - it causes a lot of issues when fish are then moved into full salinity.

I don’t think this is velvet - that is super contagious and very quick to kill.

It's been almost a week now and all the other fish are fine - I would agree that it isn't velvet, but I've never dealt with velvet

There are some posts on this forum from years ago where people say velvet can lurk in a tank and just pick fish off one by one every month or so

I have had fish losses in the same fashion in the past 6 months - stop eating, rapid breathing, then death all in about 36-72 hours or so - but I chalked that up to old age

It happened to a yellow jawfish I've had for 18 months who was very huge and probably old, and several oddball blennies that may just have short lifespans.

Almost everything I've read about Velvet is that it just wipes your whole tank out, especially if it flares up with a patient 0

Also...don't all fish die with the stop eating > rapid breathing > stop swimming/flop over > dead cycle?

 

[Jay Hemdal]

It's been almost a week now and all the other fish are fine - I would agree that it isn't velvet, but I've never dealt with velvet

There are some posts on this forum from years ago where people say velvet can lurk in a tank and just pick fish off one by one every month or so

I have had fish losses in the same fashion in the past 6 months - stop eating, rapid breathing, then death all in about 36-72 hours or so - but I chalked that up to old age

It happened to a yellow jawfish I've had for 18 months who was very huge and probably old, and several oddball blennies that may just have short lifespans.

Almost everything I've read about Velvet is that it just wipes your whole tank out, especially if it flares up with a patient 0

Also...don't all fish die with the stop eating > rapid breathing > stop swimming/flop over > dead cycle?

I’ve never seen Amyloodinium/velvet become a chronic infection, but also causing fish loss, it is always acute - massive, rapid mortalities. I can’t rule out velvet living asymptomatically in low numbers in a tank (like ich can do) but that won’t cause mortality in the fish - for fish to die from it, there needs to be an acute infection, involving thousands of trophonts.

Without a microscope, you can only infer velvet infections. However, once you’ve ruled out water quality issues (all types) then only velvet has the following symptoms: rapid breathing, not eating, hanging in water currents and death in 3 days or less.