Thread: Bacteria infection and have you added new fish

Originally Posted by alex1968

Ok this might stir up some trouble but here goes
I’ve been having bacterial issues with just my Japanese koi three of my latest ones all melted and died very quickly, water was stable no parasites found tried aquflavin and salt for weeks finally went with ct and that looks like it’s working.
Has anyone else had this problem with their ponds after introducing new koi from Japan the fish I got were quarantined before arriving in my pond and I have spoken to other people and they say the same so I’m just wondering if the problem is coming from the same wholesaler?

It could well be or something in your water. When I first started my pond I kept losing fish to bacterial issues, literally would be fine for a month or two then suddenly either get dropsy and die or a little knock which led to ulcers etc then death and nothing out of the ordinary was showing on my water tests and scrapes were clear.
In the end I got a paddling pool, chucked the fish in it and done a big dose of PP in the pond leaving it for days before draining, drying the pond then knocking up a strong dose of virkon and scrubbing all the walls before washing down and draining again then refilling. After this I literally saw instant improvement and the fish grew more in the next month than they had the 2 months previous of summer.
To confirm it helped, one of my fish got a knock not long after the refill and it healed up within a few days, whereas before that would just spiral into a bacterial infection and death.

I also had a few fish from a certain breeder and seemed to have the same issue with 3 fish so I have decided to steer clear just incase something with my pond and that breeders fish just don't work. I won't name them as it is more likely something with my pond environment than the breeder.

In line with the principle that protozoan-derived parasites are always present in all KOIs and bacterial infections can occur at any time, there is no alternative but to control outbreak situations.

Our most effective prevention methods, which we have introduced many times over, then, are the establishment of a full summer feeding period and the setting up of techniques and environments that allow young fish to nearly double in size in a short period of time.
Grow and Show in Japan

The only clear way to prevent them is through increased shoulder to back flesh and mucus volume.

In comparison, it is our frank opinion that those problems cannot be prevented by the annual schedule that still persists over there, which disregards the full feeding period, and the current situation where year-round commerce is the norm, as with consumable ornamental fish.

Selling at show stalls
This is a common sight not only in certain European countries, although it seems to be the norm for KOI immediately after importation from Japan in mid-summer to be sold in this way and then put directly into existing ponds..,

※They are the same age as the KOI raised by the Japanese hobbyists above. Compare their already transport-weary and emaciated physiques and you will realise how difficult this situation will soon become for them in the future.

Some of them are already showing the ‘flashing’ or ‘flicking’ behaviour that we are not supposed to miss as an early symptom of parasites when we do our pre-sterilisation!

Moreover, unlike in Japan, the natural water temperature is unstable at less than 20 degrees Celsius, and from our point of view, it is honestly impossible that this would not cause problems.

If this practice of ignoring the ecology of the KOI doesn't change, the problem will get worse and worse, and the bacteria and parasites will become less and less effective with repeated sterilisation, and if the fundamentals are not reviewed, the KOI will become increasingly expendable in the future, although it's good that you continue to be interested in them.

There's a few things:

1. Koi are heavily bred and thus as a result are easily stressed and seem to have lower immune responses.

2. Koi enviromentals - pathogens differ geographically. Therefore like you when you go abroad and get all the illnesses from the water and food that are naturally presents and natives have built up immunity.

3. You don't know the history - it may have been recovering from illness when you introduced it thus it's an uphill fight for the fish.

4. Pathogen resistances increase depending on the treatments and you don't know the resistance or the treatments in use. Add to that the breeder becomes a hot spot for pathogen mutation to overcome resistances. The more fish, for longer, generationally, makes a perfect pathogen breeding ground.

That's all well and good, but first of all, shouldn't we be aware of how NISHIKIGOI is established?
I often see you here quoting literature and data on carp, but carp is a species that has the ability to survive in the wild.
Natural species that grow by preying on siblings
They survive by having the vitality to feed on their siblings and grow on their own without hesitation if they lack natural food in the early stages of their juvenile life.

On the other hand, in the case of artificial breeding, it is essential to remove as quickly as possible those that have no commercial value as NISHIKIGOI, mainly those that have no pattern due to differences in viability, although they are helped to grow as much as possible on average with the help of artificial food.
Scenes of artificial culling

Of the 30 or so fish he caught, only three were selected as NISHIKIGOI, a type of juvenile fish that would not normally survive in nature without human help.
When this process is repeated several times until the autumn harvest, and when this work is carried out over several generations, it is natural that the more sophisticated the NISHIKIGOI themselves become, the weaker they become.

So how do you nurture such sophisticated but fragile KOIs??

In the five months from May to the end of September, they all achieved an average growth rate of 2.5 times.
Some of the KOIs are almost as good or better than those put into mud ponds by professional breeders.

It is for us to create the skill and environment for rapid growth in a short period of time.
The growth rates of the KOIs discussed earlier are listed below.

●From May to late September. avg. 248％growth
KOHAKU 17cm →43cm 252％growth
KOHAKU 22cm →48cm 218％growth
SHOWA 18cm →31cm 172％growth
S,UTSURI 13cm →31cm 238％growth
SANKE 20cm →41cm 205％growth
KOHAKU 8cm →35cm 437％growth
KOHAKU 21cm →44cm 209％growth
SHOWA 24cm →45cm 214％growth
SHOWA 25cm →41cm 164％growth
SHOWA 23cm →50cm 217％growth
SHOWA 24cm →49cm 204％growth
H.OGON 8cm　→36cm 450％growth

In the five months from May to the end of September they all achieved an average growth rate of 2.5 times.
Some of the KOIs are almost as good or better than those put into mud ponds by professional breeders.

The KOI has become more sophisticated over the years. However, their markets, mainly in Europe and neighbouring countries, remain optimistic and willing to take repeated doses to the extent that the T-shirts and mug of the drug manufacturers are circulating and there is no prospect of the future looking up.

Even when quality improves and large quantities of promising young KOI become readily available all year round at affordable prices, the setting of feeding periods is neglected, and even if only a few centimetres of growth is allowed during this period, sterilisation is repeated whenever a problem occurs, and the process is repeated.

If they want to stay in the same market of consumable KOIs, which they will be happy to buy again and again when they die, then it's not my place.

The natural summer water temperatures there made this impossible, but recently a few people have finally been able to compensate for this by heating the water and achieving rapid growth of young KOI in a short period of time.

Only when more and more people acquire such skill will we be able to talk about the challenges of combating parasites and bacterial infections from the same perspective and with the same standards as we do?