MORAL THREAD (is it right to Kill a sick fish???)
- Thread starter RobUK
- Start date
Actually, CO2 anesthetizes them. How it works is completely unknown, but we use CO2 on our flies, and a buddy uses seltzer to knock out his fish. They will wake right back up.
A good way to knock them out before you freeze them.
For good general info on methods, take a look at page 19 of 2000 Report of the AVMA Panel on Euthanasia
Could it be that at as the CO2/O2 ratio in the air/water increases, the kinetics of blood hemoglobin releasing CO2 for O2 becomes disfavourable? Therefore effectively decreasing O2 levels?
If I recall correctly, hemoglobin has a higher affinity for CO2 than O2, myoglobin the opposite, so the gasses trade off in tissues but in the lungs the much higher O2 concs. from our atmosphere are enough to overcome the affinity difference.
Meh, I've had coffee and thinking about that seemed more interesting that what I was already doing.
It doesn't seem to be anoxia. For one thing, flies don't have hemoglobin, and it works on them too. We don't use it in people, because elevated CO2 (hypercapnea) is extremely unpleasant. Come to think of it, I wonder what Drew's fish think of the whole soda water experience. Today is a bad day for it, but I need to take a look at a physiology text to see what is really known.
Fact is, we have little idea of how general anesthetics work. Ether was first used surgically in 1846, and its mode of action (or those of the newer compounds) is still mostly mysterious.
Fact is, we have little idea of how general anesthetics work. Ether was first used surgically in 1846, and its mode of action (or those of the newer compounds) is still mostly mysterious.
I feel pretty upset watching the fish suffer, but I think the quilt of killing them would probally be worse even though its probally in there best interests.
What I need to do I think is whats best for the fish not me, which is probally letting there suffering end
I take some solice in the fact I am not the only one who has faced this dilema and I can also take solice that they wont suffer with the methods people are suggesting.
Thanks to all who have posted, I am going to have a think for the next couple of hours. I'll post again later when I decide what to do.
It's a very difficult decision to make. It sounds like you've exhausted all your options, and it also sounds like at this point putting the ill fish 'to sleep' so to say, would be best for them, though it's hard on you.
I (thankfully) haven't had to do this, but my uncle, who has been keeping fish for a long time, has had to euthanize a few fish over the years. He fills a coffee mug 3/4 with tank water (one of those big "coffee house" coffee mugs, which he doesn't use for anything other than euthanizing and scooping out water for testing etc). Nets the fish and puts it into the cup, then he puts an alka seltzer tablet into the water, then once it's dissolved he puts the mug into the freezer, leaves it in there for a couple of hours.
Good luck, and I'm sorry for your losses.
~Tara
I (thankfully) haven't had to do this, but my uncle, who has been keeping fish for a long time, has had to euthanize a few fish over the years. He fills a coffee mug 3/4 with tank water (one of those big "coffee house" coffee mugs, which he doesn't use for anything other than euthanizing and scooping out water for testing etc). Nets the fish and puts it into the cup, then he puts an alka seltzer tablet into the water, then once it's dissolved he puts the mug into the freezer, leaves it in there for a couple of hours.
Good luck, and I'm sorry for your losses.
~Tara
Question for one of our scientist. Since fish are cold blooded, when you freeze them does their metabolic rate, and cardiovascular system slow until they become unconscious and then ultimately go into cardiac arrest (but from an unconscious state)? Or do they suffocate or maybe both?
I raise the question, because if they become unconscious from freezing then that might be a humane way of euthanizing the fish. This assumes of course that they do not experience a lot of pain from the process of being frozen - which in fact they might.
If they are sick beyond recovery and they are only going to suffer, then I would euthanize them.
Consider that If they were in the wild and got sick/weak they would probably be eaten or just die a slow death.
I raise the question, because if they become unconscious from freezing then that might be a humane way of euthanizing the fish. This assumes of course that they do not experience a lot of pain from the process of being frozen - which in fact they might.
If they are sick beyond recovery and they are only going to suffer, then I would euthanize them.
Consider that If they were in the wild and got sick/weak they would probably be eaten or just die a slow death.
Depending on the species and its adaptation to cold, neural function will fail before the fish freezes. Essentially like passing out.
Of course, if you take a fish from the arctic, with tissues full of antifreeze, it may well come out the the freezer alive and active. Not a problem with tropicals.
Of course, if you take a fish from the arctic, with tissues full of antifreeze, it may well come out the the freezer alive and active. Not a problem with tropicals.
