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Discussion Starter · #1 ·
Thought some of you might find this paper interesting.

Glucose levels in fish blood are measured to detect stress in fish, with higher amounts of glucose in the blood showing higher recent stress to the fish. The researchers in this study used an over the counter diabetic glucose meter (FreeStyle Lite) to test glucose levels in fingerling walleye they chased around in a tank and compared the results with the more intensive, intrusive, and expensive glucose tests typically used. There wasn't a perfect match between the two tests, but there was a pretty good relationship, meaning it could be a useful tool.

If anyone gets the urge to try this out themselves with a FreeStyle Lite meter, I would love to see the results.
Message the glucose reading, date, the time it took to real the fish in, fish length, location (as accurate you are willing to be), and if you have it: water depth, fish depth when marked, water or air temperature, and any other info that could be relevant; it would make my day. Let me know whether any of the above are estimates or measurements.

Only do this with fish that are already bleeding; do not injure fish to draw blood!

If the price is right, I am going to buy one of these to take on my fishing trips. I will let you know the results, and the cost of the device, if I do.
 

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The device is cheap, even free with some first purchases, its the test strips that are the real cost, last time I used one they came out to $1.00 per test.
Don't know if price has gone up or down.

Humane random blood sugars go up when under stress as well, so a hook in the mouth and being dragged out of the water and not being able to breath just may register some stress, don't think you will have any problem finding an increased level.
 

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We should start human clinical trials! It would probably have to pay real good to find volunteers though! :grin:
 

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Discussion Starter · #4 ·
The device is cheap, even free with some first purchases, its the test strips that are the real cost, last time I used one they came out to $1.00 per test.
Don't know if price has gone up or down.

Humane random blood sugars go up when under stress as well, so a hook in the mouth and being dragged out of the water and not being able to breath just may register some stress, don't think you will have any problem finding an increased level.
Good to know, thanks for the details about the costs.

I agree that catching the fish will cause them to be stressed out. I would also expect that some conditions would make them more stressed out than others...for example warmer water or a longer fight. What I would be interested in is if those differences could be detected using a glucose meter.
 

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Good to know, thanks for the details about the costs.

I agree that catching the fish will cause them to be stressed out. I would also expect that some conditions would make them more stressed out than others...for example warmer water or a longer fight. What I would be interested in is if those differences could be detected using a glucose meter.

It would be a difficult study due to a lot of factors to take into account.

First of all what is the normal blood glucose level? mmol/L
When did they eat last? (starving, engorged).
Are they sedentary = normal level
Are they in a current (exercise) = lower level
Diet - high protein= lower level, high fat content food= higher level
Fasting (during spawn) = lower level, or maybe stressed out spawning?

I'm intrigued. Just saying there are so many more variables and a need for a longitudinal study which has to take into account seasonal changes.

I no communities of humans that are near impossible to screen/treat for blood sugar levels, let alone fish.:)

All the best in your findings.
 

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Come to think about it, after dealing with a lot of type 1 diabetics (human/idiots) in a correctional facility, maybe fish would be easier to study LOL
 

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Discussion Starter · #7 ·
I'm intrigued. Just saying there are so many more variables and a need for a longitudinal study which has to take into account seasonal changes.
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I agree, to do a study properly, you would need results from a lot of fish and baseline information to ground it. Or control for some of those factors (I.e. No spawning fish).

Right now we have no information...other than what they found for fingerlings. I have no idea what to expect, especially in terms of people other than me contributing, but I will still let you know about the fish I test, for pure curiosity sake.
 

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We should start human clinical trials! It would probably have to pay real good to find volunteers though! :grin:
That info on humans and glucose/stress response has been avail for many many decades - haha but prob not gathered by trying to dunk someone underwater! But in all seriousness, the studies/knowledge is there - what makes glucose rise, and more importantly, what makes it go back to 'normal' levels.

Not sure if its the same physiology with fish, i will assume energy and stress are close to the same since fish require oxygen to live, and the cycle to get energy from oxygen is the similar (Krebs cycle)
Will be interesting to see if they can conclude the rise in glucose was due to stress (being caught on a line or caught in a nets mesh), or a byproduct of hypoxia/lack of oxygen from being out of the water, or both combined - and again, how fast they get back to normal levels once released. Add a change in water temp, and results will differ again...
Then add another entity - how does lactic acid play a role in this... lactic acid removal plays as much or more of a role in muscle recovery than oxygen does (its removed in a human via circulation and respiration). To get much more info than blood glucose alone, one would have to measure the chemistry of the respiration of the water that the fish uses to breathe - i.e. - what byproducts the fish excretes with every 'breath' thru the gills, same as we humans breath in air (that contains oxygen) and exhale that same air that has cabin dioxide in it. Measure chemistry of the water going into the fish, then measure the chemistry of the same water exiting the gills... Hmmm.... how do we do that? I am sure someone will figure it out.

So many variables, but interesting info nonetheless - i suspect the authors are finding that they are needing or wanting to do more research...
 
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