koi consuming their eggs

[Duncan]

I was asked on face book how koi consume their own eggs
well I thought Hell it should be on here its a bit complex but here tiz
enjoy

Ok here tiz, the best way to explain this and dumb it down so everyone can get a handle on it.

Remember David Blain when he hung over the Thames in a glass box for a couple of months without food? Well it all starts here. Remember he had already fasted and purged his system before he went in the glass box you did not want to see him defecating so his system was purged and voided before he went in, now the body in fact the body of all higher animals and fishes consume food for energy and the building of skeletal and muscle tissue and this includes muscle such as the heart, when it does not need any more energy the surplus is stored in the liver as glycogen when the liver is full the body starts producing FAT and stores this fat all over the body. When times are lean the liver releases glycogen back as glucose for energy and when that’s gone its starts to consume fat and convert that.

Back to David, the real danger to him was obviously starving to death but he was already lean so had very little reserve to call on so the more immediate danger was the fact once he had used up all his reserve energy with nothing left his body would start consuming itself to stay alive this is called “Catabolysis”. The body is a clever thing it knows what it can consume and in what order to stay alive as long as possible obviously should food be eventually forthcoming. The longer time goes by the more damage is done to muscle and organs and eventually they are so wasted away they can’t be repaired. This is the same with all animals, which is why you see bodies of animals more often in Africa that have died of starvation in an emaciated condition where muscle and organs have been consumed to a point where recovery is no longer possible and the boddy looks like canvas over a frame. This was the case with David Blain his doctors could see he was ok through the glass box but could not tell how far down the road of consuming his own body he had gone!

Right the koi, the koi does the same thing as animals when its deprived of nutrition it will first start re converting glycogen back to glucose and when all that reserve has diminished the fat will be consumed. It’s worth mentioning that the fat and the glycogen is not in the gut but is still broken down by enzymes and ATP Adenosine triphosphate will transport it to where it’s needed, when these reserves has run their course the carp WILL start consuming its own body but with the female it has an advantage in some cases it has a huge stash of eggs it can utilise as energy, so the female body will start with these, enzymes will break the eggs down into a molecular form and Adenosine triphosphate (ATP) will transport this energy through metabolic pathways across the cell walls to where it’s needed. The male is not so lucky he drew the short straw and does not have this hoard of energy so will start consuming himself once the glycogen and fat is gone.

So what’s the likely hood of a female koi consuming her own eggs in the UK? I would say low to nonexistent, because if you think about it, we all over feed our koi and we feed them crap they would never encounter in the wild the end result of which is, They nearly all have huge fat reserves and fatty liver disease to boot and by the time we actually start to think our koi may be egg bound its usually too late because the eggs are going rotten, and if we were to get them to consume the eggs stash, it has huge reserves of glycogen and fat it WILL use first before it starts consuming itself ( eggs)
The process of consuming eggs is very real but takes months not days or weeks and if they are fat forget it the fish will be dead from impaction long before it gets to consume the roe!!!

Hope this has helped you I can’t as I say dumb it down any further. but the technical stuff is below

Adenosine triphosphate (ATP) is a nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer ATP transports chemical energy within cells for metabolism. It is one of the end products of photophosphorylation, cellular respiration, and fermentation and used by enzymes and structural proteins in many cellular processes, including biosynthetic reactions, motility, and cell division. One molecule of ATP contains three phosphate groups, and it is produced by a wide variety of enzymes, including ATP synthase, from adenosine diphosphate (ADP) or adenosine monophosphate (AMP) and various phosphate group donors. Substrate-level phosphorylation, oxidative phosphorylation in cellular respiration, and photophosphorylation in photosynthesis are three major mechanisms of ATP biosynthesis.

[StuW]

Really interesting read Duncan and exposes many of the myths surrounding this subject.
However there is one thing which does confuse me wrt egg production in koi.
If a fully mature female does not have the correct triggers, ie daylight hours, temperature, male stimulus etc and hence no spawning what happens. Is it simply that the eggs do not mature and expand for that year and/ or future years or is there a more complex solution. I have some very happy, mature females in my pond that have never spawned and never seem to have problems due to this.

[Duncan]

stu

as i said the ratio for a normal function in a female is around 100.000 eggs per kilo of body weight normally she wont go beyond this but for some female they just don't switch off, now 100k eggs may sound a lot but its not enough to make her look huge it just gives good body shape
she will carry these eggs un-matured till the trigger comes. similarly some females don't produce any where near that amount of eggs. and of course some over produce that leads to problems

same with males I have dissected older males of 5-7 years of age and they have no gonads to speak of MOF there is a prime example in my post mortem talk I do you can see from the slide the gonad is no existent

sexual development in koi is a strange thing for example koi are hermaphrodites if there are too many of one sex in a pond or lake they can change sex and do change sex, this in the fish world is nothing unusual. for instance all common clown fish are born male and the largest of a batch of young will become female
so when we by a pair of clown fish we always buy one small one and one large one they may both be male but over time the larger of the two will become female so if you buy a big un and a small un you know eventually you will have a pair

all this just shows what a wide and diverse topic this is with no certainties

dunc

[Boycey]

Hi Duncan
I have a female koi which looks very heavily egg bound,if the chances of her consuming her eggs are non existent is the best option to put in some spawning brushes try and get her to spawn??
Thanks
Al

[Duncan]

yes Al you can spray water on the surface that sometime triggers them if you know somebody near by that's had a spawning get some of their water it will contain pheromones and that will trigger them
dunc

[Boycey]

Ok cheers,will have to get some brushes!
Al

[DaveB]

Duncan Great post and clears up a few myths. I know a few koi keepers who give their koi a 3 month winter fasting period even at temperatures of 13 degs and above and now wonder if this is a waste of time. I have usually just give my koi a month fasting and feed very little over a 4 month period at 14 degs. I have bother every year with a sttressed shiro which looks pregnent. I also have mixed sex koi with some very old males So there is not much I can do but hope nature takes its course. Best REgards Davy