[vaporize]

Hi Lee,

Was just reading at the Industry forum at reefs.org and a bunch of the wholesalers and retailers were discussing about a strain of ich that is resistant to hyposaliinity treatment, and most likely come from Vietnam.

Would you know if there is any truth to this strain and/or region? Since vietnam does have some pretty unique clownfish and the last few vietnamense clownfish I got kick the bucket in QT within a week too.

[leebca]

There are 'unofficial' reports of a strain of Marine Ich Cryptocaryon irritans) that can live at a specific gravity of 1.014. These came out of Japan about 18 months ago.

I'm afraid this 'unofficial' news has been warped and twisted in both translation and transmission.

All that is known is that Marine Ich still cannot survive a specific gravity of 1.008 to 1.010. The 'unofficial reports' have not be verified nor proven. It is not unusual for someone to make an error in the treatment process, see Marine Ich show up after the treatment and then claim the treatment didn't work. That is human nature. Aquarists especially seem to blame themselves last.

I wouldn't sweat it until a lab can actually show Marine Ich free-swimming parasites to live through a low sp. gr.

[greenbean36191]

There have been reports of hyposalinity tolerant strains from Asia for several years. IIRC Colorni talks about them in one of his papers.

[leebca]

Thanks greenbean36191. Are you referring to his 1997 or earlier work or something more recent.

One of his studies showed that the cyst lived in (I believe) 15ppt saline water and delayed producing Theronts for 28 days. However, the Theronts died at that ppt.

There are two stages of the Cryptocaryon irritans cycle that is affected by hyposalinity: Theronts and the encysted Tomonts. Each are susceptible to hyposalinity, but at different salinities, and in different ways. The most susceptible are the free swimming Theronts and they still die at hyposaline treatment levels. The cysts have been varying and some, though not killed, just delay their release of the Theronts (which do die).

Much of Colorni's work was on the cysts since at that time, it was thought that the cysts were the ones to attack and kill in any treatment process.

In the '70's when I worked on finding means to eradicate Marine Ich, the best approach was to attack the Theronts. Later that switched to the cysts. Now it's back to the Theronts.

Last year, which was a few months after I had heard the Asian rumors, I spoke in person with Dr. Edward Noga and a few other Veterinarian staff members of NCSU. At that time they too have not heard of any Theronts surviving hyposaline treatment.

To the best of my knowledge no one has showed Theronts capable of surviving low salinity. But there are always rumors and explanations on why the Marine Ich shows up after a hyposaline treatment. They often fall back on early work with cysts.

I meet with Dr. Noga in a few weeks. If you have any recent paper that might suggest otherwise to the above, I'd appreciate you providing the reference. I'd like to bring it to Dr. Noga's attention.

[greenbean36191]

There's a good chance it may not even have been one of Colorni's papers at all. I would have looked for the reference myself, but for some reason the library's databases don't work on the computer I'm using. Google scholar is all I've got at the moment and I can't find jack with it.

[leebca]

No problem. If you can think of it or come across it in the next few weeks, please keep me in mind.