Generational acclimatisation

[Lynnzer]

So many beautiful fish come from the warmer climate countries, in fact I can't think of any that come from the UK.
I was just wondering if the fish that are used to the warm water conditions can gradually be bred down through multiple generations to accept our own water temperatures. If not actual river temperatures being so damn cold in the winter, but the normal tap-water temperature or unheated tank temperature in a normal household.
I see that some species have adapted to other water parameters such as hardness, PH values etc so temperature tolerance would be a useful end result

 

[Lajos_Detari]

I think no one has tried/experimented it before.
If you use water heater and the heater in your house at above 22degC, I think most fish might be able to take it.(just my opinion)
Most fish are from the tropical countries such as South America, Africa, Asia, etc.

Probably you can do a research from the Seriously Fish website for the majority of the fish preferred temperature.
The website will give you a range of temperature for each fish species.
If you can keep them in the middle range, then they will be fine.

Just stay away from fish that prefer warmer temperature such as Blue Rams, Discus, Betta, etc.

One example here:

Boraras brigittae – Mosquito Rasbora (Rasbora urophthalma brigittae) — Seriously Fish

www.seriouslyfish.com

 

[Lynnzer]

Just stay away from fish that prefer warmer temperature such as Blue Rams, Discus, Betta, etc.

That was the whole point of the topic. Can these warm water fish be acclimated over many generations of breeding? Let's suppose that a fish has a need for a minimum temperature of 78F. So by breeding them once at let's say - 75F the fry that survive are conditioned to that temperature. Then breed from these at 72F and the cycle goes on until we reach perhaps mid 60's or even less.
I mean, that's natural selection isn't it? The survivors will be hardier fish.
We'd all still be monkeys without natural selection after all.

 

[kwi]

It'll probably be a longer process than you expect, and you don't know how the mutations you introduce will effect other factors of the fish.
I know from my scuba days that warmer waters give brighter coloured fish, so while you may succesfuly breed fish that tolerate cooler waters you may also make them less attractive at the same time.

And it has been attempted, here's one study which I'm not buying the paper on.

Maternal effects in the inheritance of cold tolerance in blue tilapia (Oreochromis aureus) - Environmental Biology of Fishes

In accordance with their tropical origin, the optimal water temperature for most tilapia species is between 25 and 28 °C. The lethal temperature varies as a function of environmental effects, individual fish histories and genetic effects; however, the genetic basis of cold tolerance in tilapia...

link.springer.com

 

[PheonixKingZ]

Many people stress the point that wild fish can survive in tanks without a heater, because, “they do that in the wild”. What these people don’t realize, is that most aquarium fish have never been in the wild, hence have no tolerance to cold water. (If they are a tropical fish)

Just my opinion.

 

[AilyNC]

We didn't evolve from monkeys. It's apes we'd a common ancestor with and the line diverged so we've humans & apes as completely seperate animals. The evolution that did take place would've happened much more slowly than you could see in a few generations of fish. Our own babies are born better adapted to eating & sleeping schedule you'd have when we lived in caves. So you can see evolution is incredibly slow & incredibly unpredictable too.

 

[PheonixKingZ]

We didn't evolve from monkeys. It's apes we'd a common ancestor with and the line diverged so we've humans & apes as completely seperate animals. The evolution that did take place would've happened much more slowly than you could see in a few generations of fish. Our own babies are born better adapted to eating & sleeping schedule you'd have when we lived in caves. So you can see evolution is incredibly slow & incredibly unpredictable too.

Thank you, finally! Someone who doesn’t believe that we evolved from primitive creatures.

 

[kwi]

Thank you, finally! Someone who doesn’t believe that we evolved from primitive creatures.

We was created by aliens............

 

[seangee]

That was the whole point of the topic. Can these warm water fish be acclimated over many generations of breeding? Let's suppose that a fish has a need for a minimum temperature of 78F. So by breeding them once at let's say - 75F the fry that survive are conditioned to that temperature. Then breed from these at 72F and the cycle goes on until we reach perhaps mid 60's or even less.
I mean, that's natural selection isn't it? The survivors will be hardier fish.

Short answer is no. They have evolved over thousands of years and a few generations can't change that. Yes the hardier specimens may survive for a while - but it would just be survival, not acclimation.

 

[AilyNC]

Thank you, finally! Someone who doesn’t believe that we evolved from primitive creatures.

That's not what I said. There's a difference between apes and monkeys. And we didn't evolve from apes but both humans and apes shared a common ancestor. To be honest I'd say we're still pretty primitive.

 

[PheonixKingZ]

Short answer is no. They have evolved over thousands of years and a few generations can't change that. Yes the hardier specimens may survive for a while - but it would just be survival, not acclimation.

Just because a fish “survives” doesn’t mean it’s thriving. @Byron ’s signature is very good:

“I notice a troubling trend in modern aquarium keepers, where the measure of welfare seems to be steeped solely in terms of survival: if the fishes live, things are good, if the fishes die, things are bad. It is an inappropriate position to take. [Nathan Hill in PFK]”

(I’m not saying you were saying surviving is thriving, I’m just pointing out what’s right)

 

[Lajos_Detari]

At cooler temperature, the fish metabolism will slow down and the fish will become inactive.
So, I guess the tropical fish just can't live in cold water. Their bodies are not created for cold water and they just can't adjust to it.