How did velvet get into the system? Newest fish was 5 years ago

[kesh]

Hey everyone,
I was reading someone situation and thought to get some views from you guys on it. There was no suggestions there.
This was the post

My scenario and have a question.
I have 150 gallon reef. All parameters good so I won’t bore you with specifics.
5 large well establish fish oldest fish are 10yr old tomato clown, purple tang, mimic tang.
Heni butterfly 7yr old and emperor angel 5yrs old.
All mature healthy since I had them. All inverts and coral in tank fine. There hasn’t been anything added.
Then I noticed angel acting odd, going to cleaner shrimp and not eating, hiding, spreading gills for cleaner.
Next day angel going to powerhead and the others not eating and noticed the color bad with dusty appearance, also eyes cloudy. I new something went bad. I got all 5 fish out and put in QT tank with copper.
That night the angel and clownfish died.
The 2 tangs and butterfly still swimming around, not eating. I got fish out on Wed night, it’s Sat now. 3 still alive, skin looks like it was peeling away in certain spots. I’m assuming this is areas were parasites infested.
I checked copper level to make sure I didn’t overdose.
How after all these years did i get Velvet in my system? The only thing I can possible think of is can it be in the frozen food? They get 5 cubes of mixed frozen a day. It’s it possible to introduce Velvet thru frozen cubes?

Another key issue is I have another reef 125, no problems there. I feed the fish that had problem freeze dried seaweed, fish downstairs no freeze dried seaweed.
Could the parasite can be in that? I know I’m reaching but trying to figure how it got in system

Thanks so much

 

[Dr. Reef]

Parasite won't survive freezing temps.
If nothing was added recently like inverts corals or live rock then most likely parasite was in the tank already but dormant and as fish were healthy and strong it probably didn't attack them till they got stressed due to some reason.

 

[Land Shark]

I can’t see how else the parasite or pathogen could have been introduced. This is concerning because I’ve always thought of frozen raw fish as a healthy thing. Sorry for your loss.

 

[Land Shark]

Parasite won't survive freezing temps.
If nothing was added recently like inverts corals or live rock then most likely parasite was in the tank already but dormant and as fish were healthy and strong it probably didn't attack them till they got stressed due to some reason.

How do you know this? Do you have any reference? Not trying to argue but many forms of life can withstand freezing temps.

 

[Land Shark]

Found a post “The introduction of a parasite to a captive system from an outside source is always a concern in our hobby. Since LRS works with some of the most the most cutting edge aquaculture projects we have processes in place to minimize any chance of a parasite surviving processing.” Then freezing is discussed.

Minimizing any chance isn’t quite the same as eliminating all risk, so you have to wonder.

 

[Dr. Reef]

Here is a link to a study conducted on ich parasite fresh and marine. Post 13 tells us it won't survive freezing.
http://www.journalofparasitology.org/doi/abs/10.1645/0022-3395(2002)088[0041:CTOIMA]2.0.CO;2?journalCode=para&code=asp-site

 

[Dr. Reef]

My years of experience is not a proof but in 25 plus years in this hobby I've never heard of ich or velvet getting into a tank through frozen food though I have heard and responded too many hobbyists where parasite was dormant or fish develop immunity and some event caused the Breakout sometimes months sometimes years down the road.
By the way there are many paid studies that are also done on this subject where I don't have access to them this was the only free one that I could find.

 

[Gareth elliott]

In general life that survives freezing has special adaptations to overcome the effects of ice crystals. Virtually all life regardless of size microscopic to blue whales, a cell’s wet mass is 70% water. These ice crystals are equally damaging on macro and microscopic scales.

In the food service industry freezing is the primary method for killing fish parasites.

Agree with @Dr. Reef was always there or came via another route, rock, coral, snail etc.

 

[Land Shark]

My years of experience is not a proof but in 25 plus years in this hobby I've never heard of ich or velvet getting into a tank through frozen food though I have heard and responded too many hobbyists where parasite was dormant or fish develop immunity and some event caused the Breakout sometimes months sometimes years down the road.
By the way there are many paid studies that are also done on this subject where I don't have access to them this was the only free one that I could find.

I was curious myself and found a technical discussion here https://forums.egullet.org/topic/119375-how-does-freezing-kill-parasites/

It does seem that freezing kills parasites in most cases. I wonder why freezing doesn’t kill bacteria?

 

[Dr. Reef]

You can kill bacteria by freezing but you need sub-freezing temperatures for that and not all bacteria can be killed parasite is a different story.

 

[HotRocks]

@kesh have you added anything at all to the tank? New corals, CUC, inverts, macro algae, live rock or sand, etc? Anything wet?

 

[Land Shark]

You can kill bacteria by freezing but you need sub-freezing temperatures for that and not all bacteria can be killed parasite is a different story.

A good discussion and appreciate your in depth knowledge sir!

 

[Dr. Reef]

Happy to help..

 

[Gareth elliott]

While in qt if the butterfly hasnt eaten yet try live worms and newly hatched brine.

 

[Land Shark]

This is interesting but I ask so that I can learn more about what matters and what doesn’t.

Freezing Food Doesn't Kill E. Coli And Other Germs
https://www.npr.org/sections/thesal...ezing-food-doesnt-kill-e-coli-and-other-germs

 

[4FordFamily]

What are the inhabitants of the 125?

My 125 was a wrasse tank with known velvet and most inhabitants fought it off until it grenaded a few years later as you describe. Even my blonde naso developed a resistance... but I killed several before I found a capable small blonde naso!

Anyhow, I cross-contaminated my 180 DTs with velvet by sticking my arms in each after the 125.

 

[kesh]

@kesh have you added anything at all to the tank? New corals, CUC, inverts, macro algae, live rock or sand, etc? Anything wet?

Its not my tank but lets assume not for discussion purposes..its somebody post elsewhere and seemed interesting

 

[Neo Jeo]

Did you add anything else to the tank? Micro algae ? Snails, star fish? Im dealing with ich now. After reading all day and night I guess ich and valvet can come on ANYTHING! That's why QT your fish before is an ok thing but if you add something else you can still get it.

 

[Daniel@R2R]

Its not my tank but lets assume not for discussion purposes..its somebody post elsewhere and seemed interesting

I don't know that we CAN assume that they didn't, especially for discussion purposes. The only way any pathogen gets into a closed system is to be introduced. The question is how would it have been introduced. The most likely culprit if no new fish were introduced is that it was introduced via water that came in with coral or some other invert. Only other possibility I can think of is some other form of cross-contamination like the one @4FordFamily mentioned.

 

[chipmunkofdoom2]

Its not my tank but lets assume not for discussion purposes..its somebody post elsewhere and seemed interesting

We can't just assume anything. Anything wet that goes in a saltwater tank from another saltwater tank can bring the free-swimming stage of most marine fish parasites. The likelihood is probably lower than with fish, but it's absolutely not zero.

If the person in question added anything new in the past 45 days without quarantining for that same time-frame, that could very realistically be the source of the velvet.