Death of a fish !!

[Duncan]

I don’t know if you guys are ready for this just yet but here goes

Question to the board and I don’t have a definitive answer to this myself

When is a dead koi actually dead ?

Given that a koi can last outside of water for a good few hours and survive. What this means is it is effectively drowning in fresh air as its totally deprived of O2. in fact a Crucian Carp (Carassius carassius) can last out of water for best part of 12 hours


In a human if we are deprived of oxygen to the brain we are dead within a few minutes whereas a carp produces ethanol to protect the brain in anoxic conditions the end results is the brain does not dehydrate in fact its getting drunk.

Also I have dissected carp and held the beating heart in my hand not attached to the carp and it’s carried on beating for a good few minutes. (In fact the Japanese eat the still beating hearts of fish as a delicacy) So its follows if the heart carries on beating outside and not attached to anything in the body the heart can beat for and undetermined indefinite period. I have always said when respiration totally collapses from anaesthetic as long as the heart is beating once we force Oxygenated water over the gill lamellae the fish is forced to oxygenate itself and recovery usually follows

So this poses the question when exactly is a fish dead? And given how long a fish can survive with no respiratory response and come back are we in fact being cruel euthanizing with anaesthetic (not taking long enough)? Would not a priest be the faster and better method. I have a theory that it’s just a load of electrical responses and a blow to the head would stop these?

Just a thought for a Wednesday morning

Dunc

Definition of Death “Death is the termination of the biological functions that sustain a living organism”.

[Gazza]

Hi Dunc,

A very good question for a Wednesday and one to get you thinking thats for sure

I myself have held a beating heart from a fish as it was you that gave it to me and one of the strangest thing i found from our dissection was that when the side was cut away from the fish you could still feel some muscle movement in this as well. Now this may just be the last bits of the nerves and muscles but it defiantly feels alive and as you say we know a fish can live outside water for a long time.

I had a Showa that jumped out the pond and smashed herself to bits all over the paving and she was out for ages as my next door Nambour come and knocked on our door and waited for a while (wife was out shopping again) so as there was no response she then run down to the in laws (who was out shopping with the wife) and same again knocked and waited a while..........time is cracking on now bless her she then run back and didn't know what to do and ended up knocking for my other Nambour and then the took out a fence panel and she pout the fish back in the water and in all this time she was bashing around all over the paving

I have thought many times and even recently as the above Showa went to the koi pond in the sky is she fully gone even though she was in a massive dose of sedation and even then i just had to make sure which is something i have always done ion the past as i believe that they can and will come round as i have heavily sedated a fish before and they come round in the end and it never surprises me just how resilient these fish can be sometimes.

Be interested to here what others think on this matter.

[Brockp]

Hi Duncan you ask some difficult questions.

Even in humans the point at which we consider somebody dead is far from agreed in fact the debate is quiet fresh as there is a push to increase the number of organ donors this has naturally raised the issue "when is a person dead ?".

In humans the physiology is quiet simple, the organs which have the highest demand for oxygen and glucose, and have only one metabolic pathway to make energy (by the oxygenation of glucose) die first. So if the breathing stops or the circulation stops the brain goes first. But the other organs can be quiet OK, so called brain death, allowing donation of organs from “a beating heart donor”.

The irony is that in other states, liver failure due to hepatitis, the brain may appear dead i.e. no brain waves for three consecutive days and the patient may still recover if the heart carries on and the liver recovers.

So in fact in man death is whatever we all agree it is, there is no absolute definition, the definition of death may vary by country, religion or even local politics.

In fish it is even harder because as Duncan so rightly pointed out they have this amazing adaptive mechanism of pickling their own brains until things improve, or not. So once again death has no absolute definition it is whatever we agree it is.

In practical days at school when frogs were dissected the live frog was anesthetised in a jar using ether and then pithed (see Wiki for definition); a long pin (mums hat pin) was pushed into the skull through the back of the neck and waggled around to scramble the brains and ensure death. The heart would carry on beating but I don’t think anybody would disagree that the frog was dead.

Using a priest is the closest we can get, in my opinion, to killing a fish. It is analogous to pithing a frog or using a stun gun or humane killer and avoids any ambiguity which “death by prolonged anaesthesia” could produce.

Well there we go time for look at the live fish.

Peter

[Duncan]

guys

i looove getting you thinking, this is another of the questions thats is not as straight forward as you imagine
And i do have a reason for asking its to change my phylosphy on euthenasia im thinkng of recommending a priest for the deadly dead its brutal for sure but its instant and not dragged out where as someone doing it with anaethetic could cause immense suffering

its similar to the statment nothing has ever been made in this life or any other without any moving parts,, think about that one for a while?

or is glass, solid, gas or liquid? these are questions designed to get you thinking out the box thought provoking or what?

back to the subject at hand

when we have qrestled with this i'll throw the same question out to the main forum and see what happens there then we will merge to two threads and see where the truth lies

dunc

[StuW]

Think Im with you on this one Duncan. Many years ago when I was a site engineer I was working in Birmingham removing the 45 year old temporary flyover in Bordesley/Small heath and as part of the job we had to exhume a grave yard at a church there. The grave yard was from the 1800s and it was very disturbing the number of coffin lids with scratch marks on them from people who had been declared dead but who were in comas or catatonic etc. I guess the point I am trying to make is that our opinion on death is ever evolving as we begin to understand the complexities of life. As somebody said you can be brain dead and still recover, be in a coma for 20 years and wake up with no apparent ill effects (except psychological) so the whole issue becomes a very grey area. For safetys sake I would anaethsetise first (even overdose) so the fish is very heavily under) and then use the priest. This might ensure that a botch job would not be so traumatic for the fish and a second or more blows could be delivered painlessly.

[boogatee]

priest only ..... never used any other method

[tomy2ponds]

This is very thought provoking I have been a fisherman for many years (not so much in the last 4 years)when trout fishing I use a priest not had any come round again,when I euthanize a Koi I use phenoxytol I leave it in there over night and give it a visit from the priest in the morning just to make sure it has gone peacefully.

[tomc]

Never really thought about it.... my standard procedure as per T2P has been to leave the koi in phenoxytol overnight, which I've always assumed was satisfactory.

Tom

[Russ Little Pond]

priest only here.

Glass is a liquid or the ale inside the glass liquid is liquid.

[Duncan]

hi

the problem and dilemma with this is what was once thought to be a given is no longer the case death is no longer an event but more like a process that in a lot of cases can be reversed

what was once thought of being clinically dead is no longer thought of in the same way people can now drown for hours and be bought back to life by gradual reheating of their core temperature indeed operations are now being performed where they clinically in effect kill people by chilling them right down to the point life ceases do the operation then start heating them back up in fact this is the only way some of these operations can be conducted its just a form of cryogenics that has not been taken to the extremes Yet!

somebody who is brain dead and being kept alive on machines is warm to the touch but clinically dead. if you connect them to a heart machine as well and take over the pumping for them you can keep them, i was going to say alive, but will change it to biologically functioning indefinatley . it makes you wonder where the cut off point is we used to think we knew the safe cut off point between life and death but this idea has now shifted dramaticaly and will continue no doubt into the future to shift even more out there

im willing to bet right now in the next few years what they can achieve now with so called "Dead" people with fade into Insignificance and whats is thought of as fantastic and cutting edge tech will seem like toytown by comparison


back to the koi. the Koi is a lot more adaptive than human life in many, many ways not least in the way it can protect its brain and shut down everything till conditions improve in fact i remember erading soemwhere about a certain tytpe of jellyfish which was thought to be immortal

with this in mind my own personal feeling is its just set of electrical impulses that for whatever the reason can operate independent of each other and can affect reversal of what was once thought of as deceased

one thing is for sure fish die naturally in a very short space of time and there is no doubt this process has taken place buty where was the more natural cut point and what induced all systemic function to cease and how can we reproduce and simulate this in euthenasia when needed in a mamal/animal this is much more straight forward , under normal conditions we stop the heart and wait and in a few minutes after the brain is staved of oxygen brain activity ceases to exist this is a known and a given but in an aquatic life form its not quite so straight forward. My fear about this is the fish could be aware but unable to react as its slowly dies of a prolonged period maybe over night with certain anaesthetics beacuse we have no way of measuring wehat we need to measure to be certain

although 2 phenoxyethanol is my favourite anaethetic i have never advocated its use in euthenasia it and phenooxitol is pretty poor at performing that function rather i use MS222 but recently i have begun quetioning that

dunc

with your permission i would like to post the frist post on the general health and we can see what the responc eis of the folks out there

dunc

[tomy2ponds]

Thats fine with me Boss

[Brockp]

Yep lets see what the other folks say.

Peter

[Manky Sanke]

Fortunately I've never had to euthenase a fish but I have thought about it. I've read about different ways to do it but they don't seem right. Putting fish into a freezer so that they quietly go to sleep, ignores what they must feel while they are being slowly frozen. I thought that leaving them in anaesthetic for a few hours might be the answer but that doesn't seem so certain now. It seems that hitting it on the head with a preist is probably the best idea so far but there is a problem with that and that is squeamishness. If you have the confidence to do it properly first time, it will be effective and the object of the excercise will be achieved - the fish will be dispatched immediately without further suffering. But what about those who are too squeamish or don't know how to hit the fish's head effectively?

A horrible example that comes to mind is from some years ago when a collegue brought an injured pigeon into work. He had seen it get hit by a car, just outside, and brought it in to see if we could help it. It didn't take long to figure out that it was beyond help and was suffering badly so someone stepped forward to put it out of its misery. "I know how to do this. Grasp the body in one hand, the head between the index and second finger like this, then quickly pull and twist". To cut a gory story short, the pigeon didn't die, it fluttered free but with its head at an unusual angle. It was recaptured and it took several more attempts, each one more gory than the last. The guy clearly had the best of intentions but whether through inexperience or squeamishness, he didn't do it correctly and ended up causing unnecessary suffering. The moral of the story is that it is one thing to have read how to do something, but it's another thing to put that into practise.

This leaves open some questions. I once saw a fisherman hold a fish in one hand in front of him and hit its head with a metal bar. It stopped flapping, he seemed quite satisfied that he had killed it and put it in his bag. Is this all it takes or had he just knocked it out and left it to die in the bag? Does it take one short sharp tap, or does it need a really good whack or will that just end up splattering blood and brains everywhere?

I would appreciate the answer to that but the wider question is how should less experienced koi-keepers be advised? Put it in a bag in the freezer or put it in some Epsom Salts with a drop of vodka may be terrible ways to dispatch a fish but they are easy methods to follow, even by the squeamish. Is there a simple to follow method involving anaesthetics and hitting a fish on the head? Most koi-keepers won't have an anaesthetic or a priest to hand but they would be able to go to a chemist and buy a bottle of clove oil. Would it be sensible to say to the ordinary koi-keeper that fish should be dispatched by putting them in a bowl of water and then adding some clove oil that had been shaken vigorously in a jar with some water to mix it, then put the fish on a firm surface and hit it on the head with a hammer?

[Duncan]

Manky

to answer one of your questions , the very last thing you should do is put the fish in the freezer even before this discussion this is a barbaric way od dispatching a fish

i dont have a difinitive answer for you on this one its a matter that i have been wrestling with myself fopr some time in light of whats being discussed here

im tending to think the priest is a time honoured method that seems clean and humane kinda like the bolt through the head of cattle. The priest is actually an elegant piece of kit its not the piece of iron bar you have in your minds eye

these have been used for possible a hundred years in trout fishing i have used these in the past long before i became interested in koi when my father and me used to go mackerel fishing we loved fresh mackerel back then. a sharp fast blow on the head dispatches the fish, the instant the blow is received the fish goes limp and lifeless and i have never seen one gain any muscle response and nore have i seen and brains splattering around its a lot more subtle than that you will see from the pic attached

dunc

[Duncan]

to answer two possers i asked earlier, glass is liquid believe it or not. in old glass im talking really old glass windows etc its found that glass is thicker at the bottom than at the top indicating the glass has been gradualy sliding down hill over many many years, a solid could not do this

and no moving parts was:: everything you think of as made of non moving parts take the silicone chip in your puter you dont think of it as having moving parts but there are millions of transistors on a CPU and all they are , are on/ off switches, moving parts they either open or close and if you take anything man made to its ultimate atomic level, atoms are constantly moving

this was just to provoke thought

dunc