Humane way to PTS a shark

I need to know what a humane way would be to PTS our ID shark. He has still not gotten any better after a week+ as he still flips on his side even though he fights it. Neither one of us have gotten any real sleep since this started & it's now time to give up.
So what would be the HUMANE way of killing him?
For the record: he may be around 15 years old.

There are several ways to "humanely" put down a fish. I've been asked this question many times while working in a LFS and have talked to vets and SPCA people to get answers that could be shared without getting into trouble.

There is the simple method of freezing - put the fish in water and container or bag and put it into the freezer. another is using alcohol - I've usually heard vodka being used, but gin and other things would do as well, I suspect. The other is using clove oil. these last two numb the fish and slow down their body functions until they expire.

That sounds like it would be slow and would cause suffering as it would take awhile to die.

On a side note: when the shark does get to swimming, he "pants" so to speak as if he's not getting enough oxygen. So I know have 2 air wands running in the tank & the filter's output is breaking up the water more as well. The shark does not want to die as he does try to fight off flipping over and when I turn him around, he swims to the other end and vice versa.

This is a difficult topic. I have used freezing before. But such a large fish would mean quite a significant amount of water to be used to reduce function.

It might be better to let him live his final days in the aquarium and then let him pass naturally. This option does not mean a quick end, but the decision is now made by you to allow nature to take its course.

alexmtl wrote:This is a difficult topic. I have used freezing before. But such a large fish would mean quite a significant amount of water to be used to reduce function.

It might be better to let him live his final days in the aquarium and then let him pass naturally. This option does not mean a quick end, but the decision is now made by you to allow nature to take its course.

To be honest, he doesn't seem like he's really ready to die. He does still eat, just not every other day. When he starts to flip over, he fights it, but needs help if he does flip. He is now currently laying on one of the bubblers.

What an unpleasant situation in which to find yourself; I don't envy the choices you are being forced to make.

I have read plenty of suggestions in many places to use clove oil, but the two times that I have been present for the utilization of this technique were very unsettling. The fish seemed to be very uncomfortable and immobilization and death were very slow to occur. It did not appear to be in any way humane.

I have personally euthanized a few fish over the years using the freezer method, but now have read that this is also very unpleasant for the animal. I still think it is far preferable to the clove oil. If using this idea, do not simply bag the fish and put it into the freezer. Rather, fill an appropriately sized container with ice water, lots of cubes. Quickly plunge the fish in and the shock of the cold water will quickly knock it out; then place it into the freezer and leave for a couple hours. With typical small fish this is almost immediate; it might take a few more seconds for such a large specimen.

Finally, for small fish I now think that simply placing the animal on a flat surface and then very quickly crushing it with a hard plank is probably best. It is not an easy task, but the fish goes from live to dead...actually, to not even being a fish anymore...virtually instantaneously. I suspect this is the most humane method for the fish...but it takes a bit more of a toll on the person. If the goal is a humane end for the animal, it's hard to imagine a better technique.

Your fish is a lot bigger, so this would be much tougher. I just discovered this thread and read the whole thing now, so you have probably already done the deed. I hope it went as smoothly and cleanly as possible. My condolences go out to you.

jjohnwm wrote:What an unpleasant situation in which to find yourself; I don't envy the choices you are being forced to make.

I have read plenty of suggestions in many places to use clove oil, but the two times that I have been present for the utilization of this technique were very unsettling.  The fish seemed to be very uncomfortable and immobilization and death were very slow to occur.    It did not appear to be in any way humane.

I have personally euthanized a few fish over the years using the freezer method, but now have read that this is also very unpleasant for the animal.  I still think it is far preferable to the clove oil.  If using this idea, do not simply bag the fish and put it into the freezer.  Rather, fill an appropriately sized container with ice water, lots of cubes.  Quickly plunge the fish in and the shock of the cold water will quickly knock it out; then place it into the freezer and leave for a couple hours.  With typical small fish this is almost immediate; it might take a few more seconds for such a large specimen.

Finally, for small fish I now think that simply placing the animal on a flat surface and then very quickly crushing it with a hard plank is probably best.  It is not an easy task, but the fish goes from live to dead...actually, to not even being a fish anymore...virtually instantaneously.  I suspect this is the most humane method for the fish...but it takes a bit more of a toll on the person.  If the goal is a humane end for the animal, it's hard to imagine a better technique.

Your fish is a lot bigger, so this would be much tougher.  I just discovered this thread and read the whole thing now, so you have probably already done the deed.  I hope it went as smoothly and cleanly as possible.  My condolences go out to you.  

He is still kickin, though still lays on the bottom. On Friday, we were told to aerate the crap out of the tank as best we could. SO I now have 2 decent bubblers goin. We still think it's his swim bladder not inflating and I found out the other night that for THE first time in 8 years of having him, the ammonia spiked. It's still in the .60 to 1.0 range and still have no clue why. No dead fish have ever been in that tank. Have done multiple 50% water changes since the weekend. I am about to take out a lot of the gravel. The FX5 has lots of bio media & I recently added Seachem Matrix to the mix. He swam around a few times but still galls when he stops.

If it were water quality issues then the other cat would be suffering as well. The increase in aeration is a decent idea, but you have successfully kept him for years with the same setup so I can only imagine that it is an organic issue.

Aeration can cause water chemistry changes but such a large ammonia spike means that there is decomposition from somewhere in the tank. In the aerobic conversion of nitrogen, the equation is catalyzed by oxygen. So the water changes make sense. The gravel can be washed a put back in as a lot of the nitrogen conversion occurs in gravel surface area, unless the gravel itself is the cause of the water quality problem due to leaching.

The sudden imbalance in nitrogen is a concern but you seem to be managing both the water and the fish ailment. I have no advice to offer other than to care as best as possible. If the cat is eating then you are doing well. Senescence of your cat is not well documented, but I assume it is gradual unlike what you see in salmon and octopus for example. Thanks for the update.

alexmtl wrote:snip

The ammonia level is down to about 1.0. I just cleaned out the tubes for the first time.
But there's also a lot of floaty crap in the tank that I never noticed before. I am doing a water change now though.