Most humane way to euthanize a fish

[Tamberav]

Hmm i am thinking to euthanize a sick velvet demsel tommorow. In freezer method, we only hv to put fish and water in freezer,right?

I would say this is probably not comfortable for the fish.

When I bought some live crab I severed it through the head/brain before tossing it in the pot.

 

[Tamberav]

I know you're kidding, but, when euthanizing a batch of pest crabs recently, I did give them some food. Figured there wasn't any harm in distracting them. It was interesting to watch them get less and less cautious as the amount of clove oil in the water increased, too; they kept eating, but they ignored me coming over to look at them.


I've seen videos of decapitated fish heads still moving, and read a study suggesting decapitation isn't humane for eels because their slow metabolism prevents quick brain death. It's also documented that snake and turtle heads can continue moving for hours after death. Chopping the brain in half would be humane, but decapitation isn't.

It is just the nerves moving even with no input from the brain (like a headless chicken running). It isn't life.

I would still try to cut something through the brain itself perhaps? That is how I dispatched of some crabs (ones I bought to eat).

 

[Tired]

Hmm i am thinking to euthanize a sick velvet demsel tommorow. In freezer method, we only hv to put fish and water in freezer,right?

Do NOT freeze fish. It's not considered humane. Get some clove oil at your local health food store or online. Put the fish in a container of water, then add a few drops of clove oil to a separate, small container of tank water. Something like a water bottle or lidded cup, with a secure lid. Shake the small container violently to mix the clove oil into the water, then add the resulting mixture, a tiny bit at a time, to the container with the fish. You should see it slow down over time, and eventually stop holding itself upright. Once it becomes completely unresponsive, including to being poked, add a decent bit more clove oil and leave it in the water overnight.

 

[Bucs20fan]

You are going to get 100 different answers here on this topic. The freezer, clove oil, severing the spine or brain. Ultimately its your fish and you do what you want with this info. For a damsel, it would be very easy to make quick. Humane, but brutal would be a knife straight down, slightly behind the eyes, it severs the spine and brain stem.

People can argue, the brain isnt dead blah blah blah, once the spine is severed, this fish will feel nothing. Its basic anatomy.

 

[Tired]

It is just the nerves moving even with no input from the brain (like a headless chicken running). It isn't life.

That /is/ the brain, though. A headless chicken can't suffer because it has no brain. A fish head with a brain still sending signals may be in distress, particularly if it's responding to being touched.

Edit:

Decapitation and brining: Experimental tests show that after these commercial methods for slaughtering eel Anguilla anguilla (L.), death is not instantaneous | Semantic Scholar

It has been too readily assumed that, like a mammal, a fish is killed immediately by decapitation, and the so-called isolated gill preparation, a standard method for studying various gill functions, but actually involving part of a severed fish head is one further example of this shallow...

www.semanticscholar.org

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2109.1993.tb00627.x

 

[Lavey29]

I guess if you are a fish in the tank it is critical that you don't cough or sneeze.

 

[Tamberav]

That /is/ the brain, though. A headless chicken can't suffer because it has no brain. A fish head with a brain still sending signals may be in distress, particularly if it's responding to being touched.

Edit:

Decapitation and brining: Experimental tests show that after these commercial methods for slaughtering eel Anguilla anguilla (L.), death is not instantaneous | Semantic Scholar

It has been too readily assumed that, like a mammal, a fish is killed immediately by decapitation, and the so-called isolated gill preparation, a standard method for studying various gill functions, but actually involving part of a severed fish head is one further example of this shallow...

www.semanticscholar.org

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2109.1993.tb00627.x

just cut it through the brain part? It is small so might be hard. I have a meat cleaver... so it would be fast...

 

[Tired]

That would be more akin to pithing, and should definitely work. It's severing the head but leaving the brain intact that's a problem, and may even be a problem in mammals; some experiments have shown 10-30 seconds of pain-like brain activity in decapitated rodents. Decapitation would be better than nothing with a severely injured animal in a lot of pain, but in all other circumstances, it's best avoided.

Pithing is best left to larger fish, though, since it is in fact hard to hit the brain in a small animal. There's a lot of potential for someone to mess up and make things worse.

When I've had to kill lizards that a cat had gotten ahold of, I've done it by putting them on the sidewalk, putting a paper towel over them to keep them calm, and crushing the head with a brick. It sounds awful, but it's instant; something can't suffer if it has no brain to suffer with. Not really a good method with fish, though, since you can't just set them on the ground.

 

[zheka757]

fish is probably dead already. died naturally

 

[ptrick21186]

I'm a fisherman so when I catch something I'm keeping I take a knife and sever the spinal cord behind the head. Instant death. But for something small like an aquarium fish....honestly....old boot you don't mind getting dirty. Kills the brain quick.

 

[Jared Bryant]

Plastic bag then quick snack with hammer. Instantly dead.

 

[Tired]

I'm a fisherman so when I catch something I'm keeping I take a knife and sever the spinal cord behind the head. Instant death.

Not necessarily. Scroll up a bit; I linked a couple of articles about decapitation in eels, and the same principle applies to other fish.

 

[Ben Pedersen]

Clove oil, when used properly, is a sedative. I've used it on both fish and crabs. Added very slowly to the container, it causes zero visible distress; they slow down, become less and less wary, and eventually pass out. Never had either of them show any signs of irritation; no head-shaking, no flashing. Heck, it's used as an anesthetic for surgeries on fish sometimes. It'd definitely be an irritant if you poured in a ton at once, so, don't do that.

Unless you've got a reputable source that says clove oil is inhumane when properly used, you might need to do some more reading.


Sometimes, yes.

Decapitation is NOT humane on cold-blooded animals, as it can take a long time for the brain to die. Pithing or otherwise destroying the brain entirely is humane, but gruesome, and can be difficult to do properly. Clove oil is probably the best bet for the hobbyist; it's hard to mess up, the opposite of gruesome, and easily available at health food stores and the like.

Freezing is highly debated but likely inhumane.

I'll have to read up on this. Maybe Clove oil, if administered properly, is an option.

I was trying to dissuade people from dumping a bunch of clove oil in a cup with a fish... That would not be humane.

 

[Tired]

Oh, that's definitely not humane, but that goes for any botched euthanasia method. We shouldn't turn people away from a safe, easy, effective option just because it can theoretically be done wrong, we should tell them how to be sure they've done it right. And any euthanasia method where you can use it on crabs and they'll keep eating until they pass out (which I've done) is a humane method.

Proper use of clove oil involves adding it slowly to the container the fish is in. It's only an irritant in high doses. In low doses, it's a sedative, and by the time it gets to an irritating level the fish is unconscious. Sort of like a two-in-one version of how veterinarians will sedate an animal, then administer a toxic solution to kill it.