Why don't miniature versions exist more often in fish?

[esoxlucius]

If the default was fish that could live in a 10g, and we could special order our weird big fish - the hobby would be just fine and there would be less dead fish involved.

I take your point.

It would indeed be fantastic for an arowana lover for example, who has very limited space, to just go and buy a dwarf one for his 55g tank. They get to keep the fish of their dreams without the need for a huge tank. Great.

But to get those once huge fish bred down to a few inches, if it was even possible, would you then end up with a fish that was so weak genetically, so messed up, that it's existence and lifespan were significantly compromised?

 

[GolemGolem]

For one thing, it's possible you'd be breeding smaller fish with genetic weaknesses/recessive genes that would get worse over time. I'm starting to see "short body" Oscars that look weird and disturbing to me. The porportions are terrible. Every new generation is a product of their entire lineage, not just immediate ancestry.

Well yeah, same things happens in all domestic animals. Pugs and bull terriers used to a lot sturdier. I'm lucky all my dogs are mutts, very few vet bills even for the elders, and they are good dogs for us. However that takes dog breeds to begin with.
edit: Think that more or less covers it Eso, hoping it stops at like Ranchu levels where they are healthy enough if you follow the rules...and it isn't ranchus and bubble eyes that are invasive species messing up the unique local flora and fauna

 

[jjohnwm]

...would you then end up with a fish that was so weak genetically, so messed up, that it's existence and lifespan were significantly compromised?

I'm sure you would...but that doesn't seem to hurt the popularity of Flowerhorns and other extreme examples of unethical breeding.

 

[GolemGolem]

My LFS has a few flowerhorn they've taken in over the last year (never seen them sell juvies) two of them seem healthy-ish. They've also taken back some P Bass a few months ago only one of those is still alive and doesn't look so hot.

 

[Omrit]

I am not saying we need them to exist. I am just asking why they don't exist.


To the comments about their not being a market for them I think that is wrong. Is there really more of a market for short bodied red tail catfish than there is for a miniature? I highly doubt it.

About them not surviving again I look at short bodied fish. The short body seems like a far greater detriment to survival given all the problems it causes with their spine and sometimes organs. If short bodied fish survive the fry stage I don't see why minis wouldn't. I mean even in regular spawns runts are common, and a serious breeder will just separate the runts if needed.


I assumed it had something to do with the way fish growth never actually stops. They don't have nearly as strict a growth period as mammals which makes me wonder if this makes it more complicated to limit their size by manipulating genetics.

 

[GolemGolem]

My best guess on why is as far as I know no one has really tried, if they had they didn't inspire others to join their project. Most fish breeding seems to be focused first on getting the fish to breed at all, then for vigor and appearance after that. The biggest of the spawn tend to have the most vigor and best appearance. Runts therefore tend to be culled or ignored, a weirder deformity might be ignored less.
Don't see why it would not be possible, and my guess is they would have less problems than short-body, long-fin, albino, electric blue or other things there is a market for. If everything is the right shape in the right spot, just smaller.

 

[RandomAlgae]

People want fishes that is around 30-60 cm and since most Aquarium fishes are already that size there are no serious attempt.

There are people who want a "Short body" fishes which is almost like a dwarf but they only grow shorter instead of smaller but these are for true monsters like RTC and Paroon shark they are readily bred too.

Then there are "mini-marble" rays which are rarer but it exist.

Even Asian arowana has X-back which is surprisingly small compared to the rest of them (45cm is average compared to 60-70 of RTG and Red)

It seem that the reason there are small selection of dwarf fishes is simply because there aren't demand for one.

Also diversity of fishes play a big role as well it is really sobering when you realize that a large ornamental fish market may hold more fishes species than a public aquarium.

Why would anyone focus on a single species or genus to produce a dwarf when they can get another fishes ?

 

[qldmick]

We have mini mollies here in Australia,
MINI MOLLIES - Premier Pet Pty Ltd
These are not balloon/short body which I wouldn't keep myself, but these mini mollies would be good for guppy tanks and similar smaller tanks.

I remember from some older fish books about runts being culled, also removing the bigger portion of a spawn for the smaller fish to catch up without the bigger siblings.

 

[Brazzen1]

I know it’s an old thread but I was just looking through the “for sale” section and keep seeing RTC listed as free or really cheap. I can only assume that this because they’ve outgrown someone’s aquarium. Since no other fish looks like an RTC or a TSN, if so please let us know, people keep buying them and having the same problem. Yeah a person can get a silver dollar and it looks like a pack, no problem, but for the rest of us there’s no alternatives. So yes there is a market for smaller, healthier versions. Maybe not a few inches but maybe a 1-2 feet instead of 4-5+ feet. A 16 inch dovii or umbe is much more practical and can sell more easily than one that grows into a 3 foot monster, especially for someone that actually cares about the fish’s wellbeing.