Ich/velvet in mandarin.

[Jay Hemdal]

I didn't get that impression - maybe we're talking about a different study. it was my impression that they randomly sampled fish in a given area during different season - and found seasonal differences - in which there was very little cryptocaryon found in season x and y (I don't remember) - and 70-80 percent in the other seasons. There were also differences between species that were fairly marked.

The paper I read (The Prevalence of Cryptocaryon irritans in wild marine ornamental fish from Vietnam) showed fish that obviously came from the commercial supply chain - the researchers did NOT catch them on their own. Look at their table 1. They purchased a selection of fish from a supplier - those fish are not all collected the same way in the same locations. My point is; the fish entered the supply chain and that affected the prevalence of CI in their samples.....

 

[MnFish1]

The paper I read (The Prevalence of Cryptocaryon irritans in wild marine ornamental fish from Vietnam) showed fish that obviously came from the commercial supply chain - the researchers did NOT catch them on their own. Look at their table 1. They purchased a selection of fish from a supplier - those fish are not all collected the same way in the same locations. My point is; the fish entered the supply chain and that affected the prevalence of CI in their samples.....

There are 2. I will try to find the other one. Re-read the one you're talking about - indeed they captured the fish - but it was my impression (possibly wrong) - that they based their 'ich or not' on their initial appearance as compared to after weeks of captivity. Either way its interesting that they found a difference based on species as well as season - which shouldn't be affected by the collection method?

 

[Jay Hemdal]

There are 2. I will try to find the other one. Re-read the one you're talking about - indeed they captured the fish - but it was my impression (possibly wrong) - that they based their 'ich or not' on their initial appearance as compared to after weeks of captivity. Either way its interesting that they found a difference based on species as well as season - which shouldn't be affected by the collection method?

Oh, I know there is seasonality with CI in Florida, so it makes sense to see it elsewhere. My comment was more about the high incidence of infection being related to the fish going through the dealers systems.

 

[Australian_Reef]

All fish have completed copper treatment and have been under observation for one week. Almost ready to add to new display. I just keep thinking delaying increases the odds that the fallow period will be successful.

Just a question that I’ve had in my mind. When an encysted tomont erupts. Are the resultant theronts genetically identical? If they reproduce asexually where does genetic variation enter into the mix?

 

[Jay Hemdal]

All fish have completed copper treatment and have been under observation for one week. Almost ready to add to new display. I just keep thinking delaying increases the odds that the fallow period will be successful.

Just a question that I’ve had in my mind. When an encysted tomont erupts. Are the resultant theronts genetically identical? If they reproduce asexually where does genetic variation enter into the mix?

My understanding is that the theronts released from a tomont are all daughter clones. However, you'll read about different "strains" of Cryptocaryon, as well as lineages that develop immunity to some drugs (I've not seen that). So - that implies some sort of change, like that offered by sexual reproduction so that genetic variability can work. However, I don't know of any point during its life cycle where genetics are exchanged.....

 

[mcarroll]

This is called epigenetics. Changing the expression of DNA without changing the DNA.

Be careful looking this up on regular google as the pop-science media has had its way with the idea, but google scholar can get articles like this for you:

Epigenetics and individuality: from concepts to causality across timescales - Nature Reviews Genetics

Recent genomic approaches are providing unprecedented opportunity to disentangle how genotype and environment affect organismal traits. The authors review the role of epigenetic variation in mediating the genotype–phenotype map across three scales: among individuals within a generation, across...

www.nature.com

 

[Australian_Reef]

Seems a ripe candidate for a vaccine!