PSA about diseases in Live Rock

[EMeyer]

Just wanted to say that over the last few months the live rock systems of at least one major wholesaler have become increasingly infested with Uronema marinum. 

I don't benefit financially from sharing this information since unfortunately I don't have any clean live rock to sell either -- the last few shipments I've had a bad run of luck getting contaminated material. They swear they don't keep fish in their rock systems but the fish DNA I find in their samples casts some doubt on that claim. 

On average overall I've found 20% of batches are contaminated. The average over the last 3 orders is 66%. My most recent order: 100%. 

Whether this is seasonal variation, just a bad run of luck in the supply chain, or an overall increase in the prevalence of this parasite in our hobby I do not know. But based on these findings I'd suggest we might want to consider imported live rock as a likely carrier of parasites just like we do the fish themselves, at least for now! 

[obrien.david.j]

Okay - I'll fess up.  I didn't know what Uronema Marinum was.   So I googled it.  

https://humble.fish/uronema/

Some quotes;

• These are the red sores most often seen on chromis damsels; however it can afflict any fish.
• There is no fallow period for Uronema. Once a tank has Uronema, it must be assumed that the disease can survive in there almost indefinitely.
• [treatment]  has a slight chance of working because usually by the time you see the red sores on the fish it’s too little, too late. 😞 I personally just euthanize the fish to prevent the disease from spreading. 

Is it really this bad?

[ocboat]

What type of live rock is contaminated?  I don't know of any "real" live rock that has been available for many years except for the Florida gulf rock.

Edited September 21, 2021 by ocboat

[EMeyer]

Indo Pacific stuff. Several wholesalers are still getting occasional shipments. NOTHING like the old days - this is the material I'm breaking up and testing for sale as Live Reef Rubble. Its not aquascaping rocks, just rubble. But its great stuff for seeding a system with microbial diversity. Until it hits the wholesaler systems and gets contaminated with Uronema. 

I have not tested any Caribbean/Gulf rock, I'm working with a supplier to test some soon. I expect that the farmed, fresh off the boat rocks will be relatively free of these things.  

 

[EMeyer]

10 hours ago, obrien.david.j said:

Okay - I'll fess up.  I didn't know what Uronema Marinum was.   So I googled it.  

https://humble.fish/uronema/

Some quotes;

• These are the red sores most often seen on chromis damsels; however it can afflict any fish.
• There is no fallow period for Uronema. Once a tank has Uronema, it must be assumed that the disease can survive in there almost indefinitely.
• [treatment]  has a slight chance of working because usually by the time you see the red sores on the fish it’s too little, too late. 😞 I personally just euthanize the fish to prevent the disease from spreading. 

Is it really this bad?

Its the most common parasite we find in aquariums. It appears to be really, really common in the supply chain. 

It can occur in tanks without any reported fish deaths. But I believe its contributing to a lot of undiagnosed deaths of recently added fish in many systems. The things that make it tricky IMO are 

a) no obvious symptoms in most cases before death, and 

b) no clear way to rid the system of it once it appears (fallow periods dont work). Some people are experimenting with H2O2 treatments and reporting good results, I've seen some pretty convincing before and after tests. 

I defer to Humblefish on the question of is it that bad, I'm just the DNA guy. But thats my 2 cents.