Balloon fish... how?

[Lysaell]

I was looking around for pictures of pearl gouramis and, well, I stumbled upon this. (Here is the link back to the source. Hope this is alright.) I was honestly horrified, this fish barely resembles anything like a pearl gourami other than the obvious colors and such. It got me thinking.

Now, I've seen quite a few "balloon" fish such as platies and GBRs. I've always disliked them, seeing how much they appeared to struggle, and stayed far far away, but I never put any thought into it. How are fish like this even bred? I mean, there's only so many ways to do it, so selective breeding of fish with short and fat bodies? Or is an off-chance kind of thing that happens enough for it to be collected and sold? If this can be done to the fish that are commercially available, could this theoretically be done to nearly any fish that has a couple characteristics that makes it possible?

Now, I'm not trying to start any discourse on the morality of balloon fish here. I just want to know the science/genetics behind this since my google searches are giving me much.

 

[Demeter]

It likely started as a genetic mutation. Someone thought it was interesting so they bred their deformed fish with siblings/parents and created a line of them. Probably just lots of inbreeding. I’m more curious to know the survival rate of fry from such pairings.

 

[Sprinkle]

Ballon mollies, ballon fish are line bred.

This is cruel, they struggle to swim like a normal fish and they are also more prone to issues.

 

[TasselledWobbegong]

The second the loaded I was taken aback, all around it just looks like a genetic mess. The spine, just wow.

But like the above mentioned it is very likely to be a line of balloon molly and serious inbreeding. Now I myself have some balloon platys, now and over the years, and they did just fine. Lived out a full life n such, but something like the above is a different side of the scale.

 

[Disglerio]

It's the same as all the odd varieties of goldfish, dog breeds, white tigers.

One random mutation in one random animal. And then a human thought "oh I like that" and bred from them, then if any offspring had the trait they took those and bred them. If none of the offspring had the trait they took the offspring and bred back to the parent, then took the resulting animals with the trait and kept breeding them to each other.

The exact genetic cause may not be known unless a scientist has researched that species and variety. There is more information available for dogs and cats. If you want to learn more, I find the genetics behind Scottish fold and American curl cats an interesting read, also the merle gene in dogs.

 

[MissPanda]

Its basically eugenics, but for pets. They see a different or unique trait and they have to inbreed to recreate this anomaly and keep breeding to get enough to establish it's new shape. They've been doing the same to dogs for centuries. That's why mutts are healthier than pure bred dogs.