Simply Koi and More Koi

Hi all did post this elsewhere, maybe in the wrong forum.

One of my fry vats holding about 250 - 40mm fry has a couple of fish constantly flashing on the bottom. These seem to be the same fish identified by their size.
This has been going on now for a couple of weeks, other fish seem to have no problems.
My questions are
1. Could it be a psychological problem with no physical presence of parasites?
2. How do you take scrapes from fry with very little mucus on their bodies?
3. How log will parasites live on dead fish before either leaving the host or dying themselves? (as I have taken scrapes from dead fry, as I can scrape as hard as I like with them)
4. How do you or others identify fry with net in hand when they all look the same and fry wriggling in the net all look the same size?
5. Also while I'm on when does Beni start to show on Kuhaku fry?

Phil

Hi Phil

If you suspect a parasite problem on fry that are too small to scrape, then I'm afraid you may have to sacrifice one and look at it under the microscope if it is very small, or try to get some mucus from it if it is a little bigger. Unfortunately, it's no good trying to do a scrape on a fry that has been dead for any length of time.

We usually harvest our fry when they have been in the mud ponds for 3-4 weeks or are on average about 1 inch long. At this stage, you can make out the pattern although pattern on some is always easier to see than on others.

Hope that helps.

Lisa

Lisa,
like you said one for the good of the many. Looks like skin flukes, only problem is what do I dose them with? I wouldn't like to use anything to strong, whilst on the other hand I do need to get shut; if I can?

Phil

Hi Phil

I have sent you a PM.

Lisa

Many thanks Lisa.


Phil