I've received a response from Dr. Colorni - one of the most cited scientists and leading experts in the world on fish disease - which I will post below.
Let me start this post by articulating my intention. My intention is to spread truth and help educate hobbyists that don't know about a particular topic - in this case, fish disease.
This forum (and hobby) is so full of myths and misinformation it's incredible. There is a lot that is still unknown about the hobby, and with so many variables we are often guessing at solutions or answers.
So when something as well understood as ich and velvet are concerned, we should not be spreading lies, myths, and misinformation. These things have a lot of scientific study behind them, and we have a very good understanding of their biology, life cycles, methods to cure them, and how to prevent them from entering our systems.
This forum should be a place where people come to learn, exchange accurate information, make friends, enjoy the hobby, etc. It
should not be a place where people spread myths, mislead people, or pretend something is based in reality when it isn't. Particularly to newbies. Which gets us to the issue here.
For those who don't want to read the email exchange, here is the summary of what Dr. Colorni said:
1) Is ich and/or velvet
always present in a home aquarium?
NO
2) Is there a scientific framework for QT methods to substantially mitigate, if not entirely prevent, the introduction of these parasites into our aquariums?
YES
I'm especially annoyed at people that make baseless claims and then disappear when they are shown to be wrong. It's nothing personal, but spreading myths and misinformation does not help the hobby. It hurts the hobby, leads to unnecessary fish deaths, and makes people leave the hobby.
@gobyvin I am still waiting for any literature to support your claims, but I am 99.9% sure there isn't any. I'm not trying to be a jerk here, but you held yourself out as an authority, and then made up a bunch of stuff that is not based on any evidence at all. You claimed:
"...most parasites are always in our systems."
This is easily disproved. Which is why I politely asked you to clarify your statement. It was an opportunity for you to revise - which you did - to this:
"I only mean that Ich and Velvet even can always be in dormant stages of their life cycle in an apparently disease free tank. Read up on this in the aquarium literature, it is a well supported view and has been tested by some. I work in marine systems (the wild) and find it hard to believe that any fish tank started with live collected rock or even little bits of it does not have some common aquarium pests hitching a ride on it. "
Ich and Velvet cannot always be in dormant stages. This is categorically false based on current evidence. No study has found ich that was dormant for longer than 72 days at reef water temperatures. And those were isolated strains. The vast majority of ich strains have a dormant period of two weeks. So you can decide how you QT to eliminate the chance of ich. I personally QT for 90 days. But if you QT for a few weeks you are basically reducing your risk substantially. Your statement is not a well supported view. Your view contradicts all known science and what most research universities and scientists believe to be true.
Then despite me asking more than once for proof of your statements, you ignored me and said this:
"The invert parasites only come out of hiding on stressed animals. If your animals are happy, you will have nothing to fight off. "
This is a fundamental misunderstanding of the life cycle of these parasites.
It's simply not true at all.
Here is the life cycle of ich:
- Trophont (feeding stage where it is on your fish) - 3-7 days
- Protomont (after it drops from your fish, it loses cilia and flattens before hitting substrate) 2-18 hours
- Tomont (encysted reproductive stage, commonly called the dormant stage) 3-72 days, majority 4-8 days
- Tomite (daughters of tomonts) the combined time for tomont and tomite stages are 3-72 days, majority 4-8 days
- Theront (free-swimming infective stage) this is the stage where ich can be killed by medication. It must find a host within 48 hours before it dies
- Trophont - back to the beginning
These parasites cannot lay dormant forever as you claim. And they do not hang out feeding on fish forever either. They stay on the fish for 7 days at the longest.
Here is one paper (there are many, many more) describing the life cycle:
http://agrilifecdn.tamu.edu/fisheri...ections-Marine-White-Spot-Disease-in-Fish.pdf
@gobyvin Again, this is nothing personal, but myths and misinformation need to be called out. It's not mean or rude to call people out for this. People should not make baseless claims if they don't want to be questioned. After this thread started, I've attempted to help you in another thread so hopefully you won't take this personally.
Anybody that thinks ich is always in our systems might as well believe the earth is flat.
And finally, here is the email exchange with Dr. Colorni, copied verbatim:
My email to Dr. Colorni:
Dr. Colorni,
My name is Andrew and I have been doing reading on fish diseases for my local aquarium club. I have read through a lot of your work and I truly appreciate your contributions to the science.
After reading your work, I think I have a good understanding of the lifecycle of crytocaryon irritans and how to prevent it from entering a closed aquarium environment. There seems to be a persistent argument amongst saltwater hobbyists that I was hoping you could settle definitively. Here are the questions:
1. Is it true that cryptocaryon irritans is always present in home aquariums? I'd ask the same question for Amyloodinium Ocellatum.
2. Assuming that the answer to the previous question is no, would you agree that there are currently known quarantine protocols that can prevent (or almost entirely mitigate the risk of) the introduction cryptocaryon irritans and/or Amyloodinium Ocellatum into a home aquarium?
If you do not have time to respond, I understand. But I truly hope you can help me with these questions.
Thank you for your time.
His response:
Dear Andrew,
Thank you for your interest in my work.
With regard to your first question: neither Cryptocaryon irritans nor Amyloodinium ocellatum is “always present” in home aquariums. However, both are often present on fish sold in pet shops.
As for your second question: the most practical and efficient method to prevent, or at least mitigate, the risk of introducing these two parasites into your home aquarium, consists in switching daily (or at least not later than every second day) any new fish between two containers for at least 2-3 weeks, taking care of drying every time thoroughly the container the fish come from. In this way any trophont (parasitic stage) potentially present on the fish will reach maturity and full size (depending on water temperature it takes a few days) and will then drop from the fish, while the thorough drying of the potentially infected container will interrupt the parasite’s life cycle in its dividing benthic stage.
Good luck,
Angelo Colorni
So
@Fishing , I hope you can now see who has credibility on this topic and who does not.
Anybody that doubts the authenticity of this email is welcome to PM me and I will provide the evidence.