View Full Version : Salt and Slugs


Orleander
07-03-12, 08:19 PM
why does salt hurt/kill slugs?

youreyes
07-03-12, 08:24 PM
Salt absorbs water, slugs loose water, they die.

http://boingboing.net/2012/06/13/salt-maze-kills-the-stupid-slu.html

Orleander
07-03-12, 08:28 PM
so salt water wouldn't kill them, just pure salt?

youreyes
07-03-12, 08:36 PM
There are plenty of sea slugs in the salty waters of the seas
I am sure however that the slugs on the surface wouldn't be too happy to be in the sea either.

Trippy
07-03-12, 09:28 PM
so salt water wouldn't kill them, just pure salt?

Osmosis on Wiki (http://en.wikipedia.org/wiki/Osmosis)

A sufficiently saline sloution would kill them just as readily as pure salt.

It's the same reason you don't put fresh water fish in salt water (or vice versa).

Asguard
07-03-12, 09:34 PM
Osmosis on Wiki (http://en.wikipedia.org/wiki/Osmosis)

A sufficiently saline sloution would kill them just as readily as pure salt.

It's the same reason you don't put fresh water fish in salt water (or vice versa).

Well actually you CAN put some fresh water fish in salt water, mollies for instance are used to dirty up a new salt water tank because they are cheep, hardy and VERY messy which forces the bacteria levels to rise. You just have to acclimatise them slowly

Trippy
07-03-12, 09:53 PM
Well actually you CAN put some fresh water fish in salt water, mollies for instance are used to dirty up a new salt water tank because they are cheep, hardy and VERY messy which forces the bacteria levels to rise. You just have to acclimatise them slowly

Yes, I'm aware that there are some fresh water fish that you can put in a salt water, and some fish which are able to cope with large variations in salinity. However, as a general rule...

youreyes
07-04-12, 01:12 AM
In a more subtly defined context on why is it exactly that salt water kills the fresh water fish ...


The ions making up the dissolved salt in the salt water jiggle at random due to Brownian motion. The ions bounce against all of the boundaries of the salt water, including a free surface. The free surface is where the salt water meets the air. When the ions making up the salt bounce against the free surface, the jiggling ions press against the liquid water molecules at the free surface. The liquid water molecules at the free surface are bonded to all of the other liquid water molecules and pull on all of the liquid water molecules, including the pure water on the other side of the semi permeable membrane. The pressure exerted by the ions making up the salt bouncing against the free surface pulls water through the semi permeable membrane

http://yarbroughlaw.com/Patent Projects/Everything you were taught is wrong.htm

Enmos
07-04-12, 03:50 AM
why does salt hurt/kill slugs?

Pour some salt into your eyes and find out.

KilljoyKlown
07-04-12, 08:39 AM
Pour some salt into your eyes and find out.

Ouch! That hurts!:D

Read-Only
07-04-12, 11:04 AM
Yes, I'm aware that there are some fresh water fish that you can put in a salt water, and some fish which are able to cope with large variations in salinity. However, as a general rule...

Yep. Another good example is salmon. They grow in fresh water until they migrate to salt water in the sea. And then they return from the salt water of the sea back to the fresh water to spawn.

And yet another example of the same sort of thing which also involves the variation in salinity you mentioned. Fish that spawn and begin their lives in saltwater marshes that get flooded with fresh water - greatly reducing the salinity every time there's a substantial rain in the area.

KilljoyKlown
07-04-12, 11:21 AM
why does salt hurt/kill slugs?

Did you forget about those speedy land snails? They foam up real good when you add salt.:D

Captain Kremmen
07-05-12, 08:29 AM
Salt is a terribly painful death for slugs.
They die in agony.
But they deserve it.

wellwisher
07-05-12, 08:51 AM
If you want to see something similar to slugs/salt, spray the slugs with liquid ammonia. The slugs will melt into a puddle. Unlike salt which dehydrates the slugs, the annomia appear to alter the interactions between water and protein so the slug changes from semi-solid to a liquid.

KilljoyKlown
07-05-12, 09:07 AM
If you want to see something similar to slugs/salt, spray the slugs with liquid ammonia. The slugs will melt into a puddle. Unlike salt which dehydrates the slugs, the annomia appear to alter the interactions between water and protein so the slug changes from semi-solid to a liquid.

Yuk! Gag me with a spoon.:D

youreyes
07-06-12, 07:27 PM
Salt is a terribly painful death for slugs.
They die in agony.
But they deserve it.

slugs don't deserve to die ... especially in agony. Just like vampires who must exist by biting into victims necks, not because of preference, but because of a will to live on and enjoy what life has to give. Or mosquitos for example...no one deserves a painful death.

KilljoyKlown
07-06-12, 08:28 PM
slugs don't deserve to die ... especially in agony. Just like vampires who must exist by biting into victims necks, not because of preference, but because of a will to live on and enjoy what life has to give. Or mosquitoes for example...no one deserves a painful death.

How does anyone know what is painful to a bug or slug, seems to me it would take more of a brain to really suffer much pain. But what do I know?:shrug:

youreyes
07-06-12, 08:38 PM
How does anyone know what is painful to a bug or slug, seems to me it would take more of a brain to really suffer much pain. But what do I know?:shrug:

I bet the Gods say the same thing when they look down on people, oh what do they know such frail creatures of anything of life. Well every creatures exists to survive and procreate one way or another, pain is a way to tell the creature that something is going wrong and will lead to death much quicker than if it was by a natural cause.
The reference is to the sea slug neuron: http://www.news.cornell.edu/releases/Feb04/Optical_recording.hrs.html
And neurons are there to signal the slug to avoid damage, to avoid pain.

KilljoyKlown
07-06-12, 09:40 PM
I bet the Gods say the same thing when they look down on people, oh what do they know such frail creatures of anything of life. Well every creatures exists to survive and procreate one way or another, pain is a way to tell the creature that something is going wrong and will lead to death much quicker than if it was by a natural cause.
The reference is to the sea slug neuron: http://www.news.cornell.edu/releases/Feb04/Optical_recording.hrs.html
And neurons are there to signal the slug to avoid damage, to avoid pain.

Yes, but I think it's a mistake to equate their pain as the same way we suffer pain. Plants also try to avoid death, but no one complains of causing plants pain and suffering. When you take soap and wash your hands, do you even consider all those bacteria you are killing? Or do you assume they going down the drain fat and happy?:D A slug or snail is a garden pest, and I have little sympathy for them and whatever kills them is okay with me.

youreyes
07-06-12, 09:48 PM
Yes, but I think it's a mistake to equate their pain as the same way we suffer pain. Plants also try to avoid death, but no one complains of causing plants pain and suffering. When you take soap and wash your hands, do you even consider all those bacteria you are killing? Or do you assume they going down the drain fat and happy?:D A slug or snail is a garden pest, and I have little sympathy for them and whatever kills them is okay with me.

No but the difference here is that we as consciouss being cause the death of other beings and take enjoyment from such practice. Thing is, a snail/slug in your garden is a pest and what kills them is okey in terms of morality. But taking pride in doing so is immoral in my sense. It is same with bacteria washed by soap, kill to survive. Do not kill for enjoyment, that is wrong.

Enmos
08-08-12, 06:48 PM
The slugs were here way before us.. about 350 million years before us.
We come along and take their land, destroy their habitats and exterminate them.
And somehow they are the pests..
Go figure. What a world.

Enmos
08-08-12, 06:53 PM
Gardens are unnatural agglomerations of mostly foreign and often invasive plants put in place by the most invasive and destructive species on this planet. How are native slugs the pests here?

Gremmie
08-08-12, 07:03 PM
Gardens are unnatural agglomerations of mostly foreign and often invasive plants put in place by the most invasive and destructive species on this planet. How are native slugs the pests here?

Two old cliches come to mind...

1) Might makes right.
2) Survival of the fittest.

Kinda leaves the slugs out.

Enmos
08-08-12, 07:05 PM
It's more like "arrogance makes it right".
Survival of the fittest? Oh come on.. the slugs have managed to survive for over 350 million years. We're just newcomers.

KilljoyKlown
08-08-12, 07:06 PM
The slugs were here way before us.. about 350 million years before us.
We come along and take their land, destroy their habitats and exterminate them.
And somehow they are the pests..
Go figure. What a world.

Have you ever had a slug race. Any starting place will do, you then take a magnifying glass and focus the suns rays to a small spot at the slugs tail and see how far you can get him to move in 30 seconds.

Actually they are not pest until they invade your garden.:D By the way have you ever seen a Washington State slug? These slugs are the biggest slugs I've ever seen. Some of them are over 6 inches in length.

Enmos
08-08-12, 07:08 PM
They are only pests according to our own egocentric definitions.
We invaded them, not the other way around.

Gremmie
08-08-12, 07:13 PM
They are only pests according to our own egocentric definitions.
We invaded them, not the other way around.

This is true. But...

Unless the slug evolves, and acquires a death ray or something, they will probably never be treated any differently than they are now.

Just sayin'

I've personally never had a slug problem, so I don't bother with them.

Live and let live... Untill you encroach upon me anyway.

defekkto
08-08-12, 10:30 PM
No but the difference here is that we as consciouss being cause the death of other beings and take enjoyment from such practice. Thing is, a snail/slug in your garden is a pest and what kills them is okey in terms of morality. But taking pride in doing so is immoral in my sense. It is same with bacteria washed by soap, kill to survive. Do not kill for enjoyment, that is wrong.

So if you wash your hands more times then necessary or just because you enjoy doing so then that is wrong?

KilljoyKlown
08-08-12, 10:48 PM
They are only pests according to our own egocentric definitions.
We invaded them, not the other way around.

Actually I would prefer to keep them out of the garden in the first place. I've heard if you put a ring of rock salt around the garden the slugs will avoid it like the plague.

Enmos
08-09-12, 07:20 PM
This is true. But...

Unless the slug evolves, and acquires a death ray or something, they will probably never be treated any differently than they are now.

Just sayin'

I've personally never had a slug problem, so I don't bother with them.

Live and let live... Untill you encroach upon me anyway.
If they evolve any smarts at all, that will probably be that last thing they will ever do. Let alone when they would acquire a death-ray.. lol

Enmos
08-09-12, 07:20 PM
Actually I would prefer to keep them out of the garden in the first place. I've heard if you put a ring of rock salt around the garden the slugs will avoid it like the plague.

Wouldn't that wash away and harm your plants?

MRC_Hans
08-10-12, 07:30 AM
Salt is a terribly painful death for slugs.
They die in agony.
But they deserve it.

Actually, slugs are unlikely to experience pain in the sense we do. Pain is useful to us, because we can take flight, learn to avoid damage, spare a wounded limb, etc.

The slug cannot take flight, it cannot learn, and it has few choices of ways of moving, so ... in short, it has little use for pain. The defence strategy for a slug is to contact to smallest possible extent (near round) and excrete a slime cocoon, - repeat as needed. This is the reason salt kills it: As a reaction to the salt, it keeps excreting slime till it runs out of water.

For a creature with such a low organization the only way to kill it quickly witout apparant agony is either squashing it totally (yuck!), or immersing it in boiling water. Compared with everything else, salt seems neither better nor worse, provided there is salt enough.

Hans

MRC_Hans
08-10-12, 07:35 AM
The slugs were here way before us.. about 350 million years before us.
We come along and take their land, destroy their habitats and exterminate them.
And somehow they are the pests..
Go figure. What a world.

It is called evolution. The natural world has no morals. It is full of creatures that would gladly take our place, if they could.

Hans

MRC_Hans
08-10-12, 07:40 AM
Have you ever had a slug race. Any starting place will do, you then take a magnifying glass and focus the suns rays to a small spot at the slugs tail and see how far you can get him to move in 30 seconds.

Actually they are not pest until they invade your garden.:D By the way have you ever seen a Washington State slug? These slugs are the biggest slugs I've ever seen. Some of them are over 6 inches in length.
True, of course, but all species are ultimately invasive: They took their habitat from some other species. Humans, however, are exceptionally good at it.

Hans

KilljoyKlown
08-10-12, 08:24 AM
Wouldn't that wash away and harm your plants?

Have an elevated garden and add salt as needed. Of course snail & slug bait also works quite well.

KilljoyKlown
08-10-12, 08:32 AM
True, of course, but all species are ultimately invasive: They took their habitat from some other species. Humans, however, are exceptionally good at it.

Hans

We are not taking their habitat, we are merely restricting it. Animals that want to survive in a human world need adapt or go extent. They need to become pets like dogs and cats or food like farm animals. There are probably more chickens alive now than at any time in the history of the earth.:D

defekkto
08-10-12, 09:36 PM
It is called evolution. The natural world has no morals. It is full of creatures that would gladly take our place, if they could.

Hans

I agree, of course we shouldn't go out of our way to cause harm to other species but if animals are in danger of extinction it's because they aren't adapting to our ever-changing world and extinction is just another regular process of the earth.

FTLinmedium
08-11-12, 09:36 AM
Actually, slugs are unlikely to experience pain in the sense we do. Pain is useful to us, because we can take flight, learn to avoid damage, spare a wounded limb, etc.
The slug cannot take flight, it cannot learn, and it has few choices of ways of moving, so ... in short, it has little use for pain.

The first point is completely false- slugs are mobile. Animals that can not feel pain at all don't have brains at all- completely sedentary animals, such as oysters.

Slugs do have brains- and the only thing that would make them useful is a capacity to feel pain- and the only use they have is some capacity for learning and adaptive behavior.

So, your second points is false too.

I'd bet good money that they can learn in a substantial and easily testable way, too. Take some electrodes and give a slug a little shock every time it turns left. Or include two kinds of leaves it likes, and shock it whenever it starts munching on one type but not the other.

Not the nicest of experiments, but it's entirely testable. I've heard of simpler animals than slugs being capable of very basic learning (on that level).

Slugs may not experience as much pain, having a lesser capacity to process it, but they certainly experience pain as real and meaningful as we do because it's necessary to guide their actions towards the most optimal behavior for the best use of the resources they have.

They choose their environments, their food sources, and basically avoid things that harm them.

That's not to say you shouldn't kill them if they're infesting your gardens. But it's just pseudoscience to suggest they can't feel pain.

KilljoyKlown
08-11-12, 10:12 AM
The first point is completely false- slugs are mobile. Animals that can not feel pain at all don't have brains at all- completely sedentary animals, such as oysters.

I'm not so sure oysters don't experience some kind of pain. After all one of the reasons they make perils, is because a grain of sand is irritating them. However how we or different creatures experience pain is up some debate.

FTLinmedium
08-11-12, 11:08 AM
I'm not so sure oysters don't experience some kind of pain. After all one of the reasons they make perils, is because a grain of sand is irritating them. However how we or different creatures experience pain is up some debate.

Our bodies encapsulate foreign material too- we don't do it consciously. I don't know if we can personify the experience an oyster has as irritation.

KilljoyKlown
08-11-12, 12:15 PM
Our bodies encapsulate foreign material too- we don't do it consciously. I don't know if we can personify the experience an oyster has as irritation.

Any organism that responds in any way to mitigate damage to itself must be responding to a pain of some kind. Having said that, I'm also sure humans experience pain differently than lower forms of life do.

FTLinmedium
08-11-12, 09:48 PM
Any organism that responds in any way to mitigate damage to itself must be responding to a pain of some kind.

False assertion. Reflexive and automatic behavior has no need for pain- pain is only present where there is cognition and the ability to learn and adapt in a dynamic way.


Having said that, I'm also sure humans experience pain differently than lower forms of life do.

If it looks like a duck, and quacks like a duck...

Pain serves exactly the same purpose in all life forms capable of basic cognition- it guides the evolution of the neural networks with negative feedback. The qualia is of an inherently identical nature. It may exist in varying quantities and degrees- depending on capacity for cognition- but the nature is the same.

If you're skeptical about that, you're making the same philosophical blunder as a solipsist.

KilljoyKlown
08-11-12, 10:08 PM
False assertion. Reflexive and automatic behavior has no need for pain- pain is only present where there is cognition and the ability to learn and adapt in a dynamic way.

When I pull my finger away from something hot, that's automatic behavior, but being burned still hurts like hell. I really can't say how a slug feels when it gets burned and neither can you or anybody else. All we can do is observe the physical reaction. I have no doubt that the slug hurts when it gets burned, I just don't care very much whether it in pain or not.

FTLinmedium
08-12-12, 07:46 AM
When I pull my finger away from something hot, that's automatic behavior, but being burned still hurts like hell.

I didn't say it wasn't sometimes accompanied by pain (in your example, reflexes and learning function side by side). An automatic reflex doesn't provide evidence for pain, though. Those we know don't feel conscious pain, like the brain dead, can also have reflexes and encapsulate foreign material. Likewise, plants which are equally incapable of feeling pain can act quickly and reflexively through a cascade of simple chemical reactions (such as fly traps closing).



I have no doubt that the slug hurts when it gets burned, I just don't care very much whether it in pain or not.

Of course that's fair- a garden pest is a garden pest. Whether they were tiny gnomes with complex societies, art, music, etc. or mindless blobs incapable of sensory perception at all, they'd need to be eliminated to protect our food supply.

It is certainly more comforting to imagine that they are closer to the latter than the former- though that doesn't make it true. If we strive to be critical thinkers, we should be extra careful with our assumptions when we have such a motivation to lie to comfort ourselves.



I really can't say how a slug feels when it gets burned and neither can you or anybody else. All we can do is observe the physical reaction.

We'll just have to disagree on that point. I think it's quite easy to say, and anything else resembles to me overly severe philosophical skepticism.