water temperature and stress to fish

[bettasngoldfish]

So is it true that the lower (or higher) the water temperature is the more stressed out your goldfish or koi will be? Which is more dangerous to the fish?

The one thing that comes to mind in higher water temperatures is that the oxygen content is lower.

 

[MitchM]

I don't consider typical pond temperatures to be a stressor for goldfish or koi.
I consider typical pond temperatures to be between 33f and 80f.

 

[barryian]

I don't consider typical pond temperatures to be a stressor for goldfish or koi.
I consider typical pond temperatures to be between 33f and 80f.

Yes, I think the word stress should be change to immune system. That's what is lowered with lower temps. Here's an excellent blog to bookmark when anyone has time to read it ...

http://koihealthadvisor.org/kha_images/pdf/ColdWaterEffect.pdf

 

[MitchM]

Yes, I think the word stress should be change to immune system. That's what is lowered with lower temps. Here's an excellent blog to bookmark when anyone has time to read it ...

http://koihealthadvisor.org/kha_images/pdf/ColdWaterEffect.pdf

The author of that article was based in California.
People from California should not write articles on cold weather.
In the article he states that your pond should be at least twice the depth of your frost line. That means my pond should be nearly 10 feet deep if I followed his advice.

 

[Dave 54]

The shallower the pond the quicker the pond will chill rapid chilling is dangerous to both koi and goldfish and can kill, but the other end of the scale in a shallow pond can prove just as dangerous .
This is why we recomend a minimum depth of 4.5ft with an ideal depth for your pond being 5ft in depth...
Yes you guys get harsher winters than we do here in the UK but the same apply's especially if you live in the North of the UK .
Koi that have the latent Koi herpes virus can become stressed at higher water temperatures activating the virus to the detriment of all your koi....
But then again many other things can cause stress and the activation of the virus .
see link :-

https://www.gardenpondforum.com/articles/khv-cyhv3.27/

Dave

 

[Meyer Jordan]

Before this thread quickly goes of on a tangent discussion about proper pond depth (that horse has already been beaten here on this Forum), let's first agree on what we are discussing.

Stress-
a specific response by the body to a stimulus, as fear or pain, that disturbs or interferes with the normal physiological equilibrium of an organism.

With this definition in mind temperature extremes may or may not act as a stressor of Koi, Goldfish or any other specie of fish. The reason for this is acclimatization. A fish that has adapted to the prevalent climate of a geographical area will not noticeably experience any level of stress caused by moderately low or high temperatures. Fish that are not adapted will experience levels of mild to severe stress depending on lack of adaption, This, of course, excludes the minimum and maximum temperatures tolerated by individual species for basic survival.
It is a well known fact that fish physiology differs depending on the prevailing climate and its adaption to it. For instance, Koi adapted to warm water climates will have more Red Muscle mass than their cold water counterparts and cold water adapted Goldfish have a larger ventricular mass (bigger hearts) than their warm water counterparts.

 

[barryian]

The author of that article was based in California.
People from California should not write articles on cold weather.
In the article he states that your pond should be at least twice the depth of your frost line. That means my pond should be nearly 10 feet deep if I followed his advice.

Before this thread quickly goes of on a tangent discussion about proper pond depth (that horse has already been beaten here on this Forum), let's first agree on what we are discussing.

Stress-
a specific response by the body to a stimulus, as fear or pain, that disturbs or interferes with the normal physiological equilibrium of an organism.

With this definition in mind temperature extremes may or may not act as a stressor of Koi, Goldfish or any other specie of fish. The reason for this is acclimatization. A fish that has adapted to the prevalent climate of a geographical area will not noticeably experience any level of stress caused by moderately low or high temperatures. Fish that are not adapted will experience levels of mild to severe stress depending on lack of adaption, This, of course, excludes the minimum and maximum temperatures tolerated by individual species for basic survival.
It is a well known fact that fish physiology differs depending on the prevailing climate and its adaption to it. For instance, Koi adapted to warm water climates will have more Red Muscle mass than their cold water counterparts and cold water adapted Goldfish have a larger ventricular mass (bigger hearts) than their warm water counterparts.

Again, all that said, discounting stress, the lower the temp, the immune system becomes more compromised. This in turn opening a scenario possibly to more likely problems when temps warm and though they're present all the time, pseudomonas and aeromonas are always preying on the koi, figuratively speaking. With a better immune system at a higher water temp in winter along with a healthy slime coat and good quality water parameters, all should be well. In this case, with an accidental scratch the koi can carry on unscathed, rather than the area turning into a bacterial infection. Actually, at 60F, I believe the koi's immune system is at 50%. At 45F, naturally less and at 32F, it's low... But my whole point was way back when I was asked about the 45F winter water temp, my answer was, it should improve the koi's chances when coming out of winter due to a better immune system than at 42 or 43F.
I believe that's we we left off.

 

[Meyer Jordan]

With any cold-blooded animal lower temperatures means lower metabolic rates means lowering or slowing down of all other physiological functions including the function of the immune system. This is why fish are prone to pathogenic issues in Spring. Parasitic organisms resume normal function before fish do allowing them an 'edge' even if only for a short period of time.
This was not the question presented as subject of this thread and should be discussed elsewhere.

 

[Meyer Jordan]

Here, for what its worth, is an interesting chart on temperature acclimatization in Goldfish.

 

[MitchM]

Here, for what its worth, is an interesting chart on temperature acclimatization in Goldfish.
View attachment 89778

I don't understand what this graph represents.
I understand that sudden temperature changes are unhealthy, but the graph doesn't include any time values.
It seems to be telling us that a goldfish kept at 30C can never survive at a temperature below 9C.

 

[Meyer Jordan]

I had the same reaction. This is why i stated "for what its worth". I also noted the publishing date for this chart is 1942. I am guessing that this graph was constructed using empirical mathematical data that was available at that time. This was well before it was discovered that Goldfish could produce 'anti-freeze'. That being said this graph applied to other species of fish, has been proven to be fairly accurate in more recent research. As a fish approaches either the high or low limits stress increases.
There is also some confusion between acclimation and was is termed "final preferendum'. Final preferendum is the temperature that a specie will eventually gravitate to as a preferred temperature given sufficient time.
The temperature for maximum growth for Koi (and this should raise some eyebrows) has been determined by several independent research projects to fall in the range of 79F - 82F. It is logical to assume that because of this homeostasis is minimal at this range and therefore this would be the final preferendum for Koi.

 

[MitchM]

I found this article that seems to state that fish kept in captive environments (hatcheries) have a different genetic makeup than wild varieties.
Perhaps with the close quarters and intensive localized breeding that our koi/goldfish go through, all us pond keepers observe different adaptations that our fish have made. (including temperature tolerances)
I'm not decided though, whether the adaptations are from existing genes or from actual DNA changes.
http://www.eurekalert.org/pub_releases/2016-02/osu-des021216.php

.

 

[Meyer Jordan]

If genetic changes can be made in the hatchery environment, then conversely genetic changes can be made outside of the hatchery environment.....Most in the scientific community, I believe, would call this adaption.

 

[Mmathis]

To me, a "stressor" is anything that changes drastically from what is the norm. Drastic and rapid changes don't give the organism [fish, in our case] a chance to adapt, making them more susceptible to harm from infections, etc. Goldfish are a cold water species, but do well at higher temps. Deeper ponds allow for a slower temperatue exchange -- hot is still hot, but it will take it longer to get there.

Just my 2 cents.

 

[Meyer Jordan]

a "stressor" is anything that changes drastically from what is the norm.

Good definition!