Why is line breeding often considered a responsible practice in the breeding community?

[FishandFins]

I'm genuinely curious about why line breeding is seen as a responsible way to breed fish. I understand it's not as severe as 'inbreeding' since you breed the fish with indirect relatives like their grandparents or cousins. However, isn't that still a form of inbreeding? While the offspring may be healthier with cousins as parents rather than if their parents were siblings, I doubt they would be as healthy as fish whose parents weren't related.

I also get that inbreeding and linebreeding can increase the chances of certain aesthetic traits, such as unique colours or patterns. But, personally, that makes me uneasy because breeding animals for their aesthetics makes me see them more as cool toys rather than animals (especially since any kind of inbreeding tends to have negative impacts for most creatures). Then again, I'm not an expert in line breeding, so maybe I'm coming off as ignorant.

I would also appreciate hearing opinions on whether you agree with this or not because I'm curious about the topic of line breeding and would like to learn more about it!

 

[GaryE]

You'll find extremes on this one. We're going philosophical.

I don't linebreed, preferring to attempt to keep wild type fish. But I recognize the skills involved in linebreeding, even if I don't always appreciate the results.

My starting point is that every fish we keep has been the victim of a predator. It can't be returned to the wild, because of its exposure to captive diseases. It is alive, but to its all important breeding population, it's a zombie. You can eat a caught fish, or you can propagate it. I can well see where our ethics as fishkeepers can be questioned... but animal care is part of what our species does. Whether it's dogs, cats, fish or snails, we like to have other animals around us, and they don't get a choice.

I put value on fish watching. It fascinates me. Fish evolution is an incredible story, and I want to learn as much as I can.

Others put value on aesthetics, or on genetics, and they linebreed. When I see fish like flowerhorns, glofish, fancy Bettas or blood parrots, in my view, they are worthless. It's a judgment call based entirely on what I like. There is no higher power behind it, no rule, no law of nature, no objective criteria. I see hybrids, I see trash fish. If you disagree with me - you have excellent reasons to. We can't even argue it as taste is pure opinion and nothing can back it up.

The entire hobby is a bunch of primates sitting around playing with their food.

How we play depends on what we want. Most hobbyists see fish as disposable ornaments. Others like to modify their appearance through linebreeding. Some view the hobby in purely commercial ways. Others try species conservation through captive breeding. Some find interest in breeding wild types. The whole starting point is a little weird if you think about it, and here we are.

 

[jaylach]

I THINK that I understand what you are saying about line breeding although I must admit to not ever actually hearing the term. I may be wrong but would think that, in nature, line and in breeding would be a natural thing. Not all but many species tend to stay in the same area as they were born so such breeding is going to happen in nature. The bad results tend to die off without propagating so no harm.

The problem is with breeders that do this to bring out traits they want to achieve often for profit from sales. This is different than what I said about nature above as the breeder will intentionally preserve a genetically faulty fish just due to it having the desired color or other aspects. To me this is totally wrong and hurts both the species and the hobby.

Way back when I was ignorantly guilty of this a bit as I bred Black Delta Veil Tail guppies when I was like 13, and knew nothing, to sell the young. The tails were longer than half the body. This is just not healthy. The same can be said for betas that are bred for extremely large fins. The fins/tails are just so heavy that it basically exhausts the poor fish just in swimming. This leads to poor health and short lives.

The problem isn't line or in breeding as that happens all the time in nature. The problem is breeders that could not care less about fish health and only care about the $$$$$$$$$$. Just my opinion.

 

[GaryE]

To get a linebred form takes many many generations of working with a plan toward a goal - a modified fish. As I already said, that has no appeal to me, but it's a meticulous process and you have to respect the skills of the breeder.

An early 20th century linebreeder, Dr Myron Gordon, crossed platys and swordtails and realized it triggered skin cancer in the offspring. Evolution leaves us and them with the same sort of Melanoma, and the Xiphophorus family has now been heavily researched to teach us a lot about ourselves.

I keep killifish, and they often live in small populations in limited ranges. Some species are only found in one creek or small system. One that I have seems to only exist in a narrow 3 or 4 km stretch of a spring fed river in the Congo Region. Inbreeding is not just an aquarium thing, and these fish are genetically very robust. I recently read an article from a respected scientist suggesting that outbreeding could be a danger to them as the gene pool had distilled down to its basics over thousands of generations of inbreeding. In some ways, they have become almost like sexually produced clones. It speaks ill for their future with climate and habitat change, but it's an interesting part of the puzzle. What remains of some species have largely eliminated the negative mutations.

There are even self cloning hermaphrodite fish in aquariums.

With other fish from other contexts, you can see inbreeding signs within a few generations of aquarium breeding. They're often the species that are the easiest to modify, if you are into that. So we can't just talk about inbreeding without learning the natural history of the fish we're interested in.

So much of what is out there to be learned about with a number of small, inedible, commercially unimportant fish has come from aquarists breeding them and sharing notes. If you're the curious sort, you may make a contribution there. If you just look at them, you just see a fish.

 

[FishandFins]

Th

You'll find extremes on this one. We're going philosophical.

I don't linebreed, preferring to attempt to keep wild type fish. But I recognize the skills involved in linebreeding, even if I don't always appreciate the results.

My starting point is that every fish we keep has been the victim of a predator. It can't be returned to the wild, because of its exposure to captive diseases. It is alive, but to its all important breeding population, it's a zombie. You can eat a caught fish, or you can propagate it. I can well see where our ethics as fishkeepers can be questioned... but animal care is part of what our species does. Whether it's dogs, cats, fish or snails, we like to have other animals around us, and they don't get a choice.

I put value on fish watching. It fascinates me. Fish evolution is an incredible story, and I want to learn as much as I can.

Others put value on aesthetics, or on genetics, and they linebreed. When I see fish like flowerhorns, glofish, fancy Bettas or blood parrots, in my view, they are worthless. It's a judgment call based entirely on what I like. There is no higher power behind it, no rule, no law of nature, no objective criteria. I see hybrids, I see trash fish. If you disagree with me - you have excellent reasons to. We can't even argue it as taste is pure opinion and nothing can back it up.

The entire hobby is a bunch of primates sitting around playing with their food.

How we play depends on what we want. Most hobbyists see fish as disposable ornaments. Others like to modify their appearance through linebreeding. Some view the hobby in purely commercial ways. Others try species conservation through captive breeding. Some find interest in breeding wild types. The whole starting point is a little weird if you think about it, and here we are.

This is interesting! It makes me question the ethics of keeping fish. I also didn't realize how we introduce fish to many diseases. I always just assumed that wild fish were stronger due to how irresponsibly some captive fish have been bred.

I also agree with some fish being seen as worthless, as Goldfish were what brought me into the hobby eight years ago. Yet now, when I see the fish I used to admire for their appearances, such as the butterfly telescope or pearl scale, I am disturbed by how deformed they appear. So many 'unique' characteristics we have given them harm them. Their round bodies make them more prone to swim bladder disorder. The telescope's eyes make it harder for them to see. The fatty growths on the orandas and ranches are constantly growing to the point that they require surgery and are also prone to bacterial infections. The list goes on regarding how we have ruined these animals to make them 'cool' or 'cute,' and they have no choice.

 

[Back in the fold]

@GaryE “The entire hobby is a bunch of primates sitting around playing with their food” . My mind is well and truly blown ! I thought about that statement and then I thought some more and I think that’s a fair statement . Still , my mind is blown !

 

[Back in the fold]

To get a linebred form takes many many generations of working with a plan toward a goal - a modified fish. As I already said, that has no appeal to me, but it's a meticulous process and you have to respect the skills of the breeder.

An early 20th century linebreeder, Dr Myron Gordon, crossed platys and swordtails and realized it triggered skin cancer in the offspring. Evolution leaves us and them with the same sort of Melanoma, and the Xiphophorus family has now been heavily researched to teach us a lot about ourselves.

I keep killifish, and they often live in small populations in limited ranges. Some species are only found in one creek or small system. One that I have seems to only exist in a narrow 3 or 4 km stretch of a spring fed river in the Congo Region. Inbreeding is not just an aquarium thing, and these fish are genetically very robust. I recently read an article from a respected scientist suggesting that outbreeding could be a danger to them as the gene pool had distilled down to its basics over thousands of generations of inbreeding. In some ways, they have become almost like sexually produced clones. It speaks ill for their future with climate and habitat change, but it's an interesting part of the puzzle. What remains of some species have largely eliminated the negative mutations.

There are even self cloning hermaphrodite fish in aquariums.

With other fish from other contexts, you can see inbreeding signs within a few generations of aquarium breeding. They're often the species that are the easiest to modify, if you are into that. So we can't just talk about inbreeding without learning the natural history of the fish we're interested in.

So much of what is out there to be learned about with a number of small, inedible, commercially unimportant fish has come from aquarists breeding them and sharing notes. If you're the curious sort, you may make a contribution there. If you just look at them, you just see a fish.

You just invoked the legendary Dr. Myron Gordon . A hushed awe falls over the crowd . THAT is a name I have not heard in many years .

 

[Magnum Man]

We can choose to ignore it, but as long as their is profit to be made, or praise heaped on a breed, and the breeder, it will continue… some people think, well it’s just a fish… but it goes on with dogs and cats, pigs, cattle, horses…

It likely happens with most fish, as your average fish keeper gets a group, there is a good chance this fish in their group all came from the same brood, yet when they mature often a pair will breed… these brother/ sister pairs are breeding all the time in home aquariums

 

[GaryE]

I think a lot of the health issues and deformities we used to blame on inbreeding are now known to be poor raising of fish, or disease. The fish farms have a problem no one will ever overcome - extreme overcrowding and its tendency to spread disease. The business is a cut throat one, and every fraction of a penny saved adds up over the tens of thousands of fish they sell worldwide. Any farm that raised fish as they were raised 50 years ago would be bankrupted by the purchasers for the chains. The more we trend toward monopolies, the more power they have over suppliers.

That isn't going to change.

I don't think fishkeeping's an overall matter of ethics though. We can do things in alternative ways, if we really get into it. For whatever reason, we seem to need pets, things we can nurture, house plants, fish, dogs, etc. Just as there are breeds of dog I would never buy, there are breeds within fish species I run away from. I pet the pug and the French bulldog I meet on my dog walks, when the poor things come snuffling, snorting and wheezing up to me. I would never encourage their breeding, but they're nice dogs, and as an asthmatic, I can appreciate their issues. Their people are kind and loving to them, and probably didn't think about the handicaps before they sought the dogs. Their choice, but not mine. It's the same with fish.

 

[OldFishKeeper]

I'm genuinely curious about why line breeding is seen as a responsible way to breed fish. I understand it's not as severe as 'inbreeding' since you breed the fish with indirect relatives like their grandparents or cousins. However, isn't that still a form of inbreeding? While the offspring may be healthier with cousins as parents rather than if their parents were siblings, I doubt they would be as healthy as fish whose parents weren't related.

I also get that inbreeding and linebreeding can increase the chances of certain aesthetic traits, such as unique colours or patterns. But, personally, that makes me uneasy because breeding animals for their aesthetics makes me see them more as cool toys rather than animals (especially since any kind of inbreeding tends to have negative impacts for most creatures). Then again, I'm not an expert in line breeding, so

You'll find extremes on this one. We're going philosophical.

I don't linebreed, preferring to attempt to keep wild type fish. But I recognize the skills involved in linebreeding, even if I don't always appreciate the results.

My starting point is that every fish we keep has been the victim of a predator. It can't be returned to the wild, because of its exposure to captive diseases. It is alive, but to its all important breeding population, it's a zombie. You can eat a caught fish, or you can propagate it. I can well see where our ethics as fishkeepers can be questioned... but animal care is part of what our species does. Whether it's dogs, cats, fish or snails, we like to have other animals around us, and they don't get a choice.

I put value on fish watching. It fascinates me. Fish evolution is an incredible story, and I want to learn as much as I can.

Others put value on aesthetics, or on genetics, and they linebreed. When I see fish like flowerhorns, glofish, fancy Bettas or blood parrots, in my view, they are worthless. It's a judgment call based entirely on what I like. There is no higher power behind it, no rule, no law of nature, no objective criteria. I see hybrids, I see trash fish. If you disagree with me - you have excellent reasons to. We can't even argue it as taste is pure opinion and nothing can back it up.

The entire hobby is a bunch of primates sitting around playing with their food.

How we play depends on what we want. Most hobbyists see fish as disposable ornaments. Others like to modify their appearance through linebreeding. Some view the hobby in purely commercial ways. Others try species conservation through captive breeding. Some find interest in breeding wild types. The whole starting point is a little weird if you think about it, and here we are.

I now agree 100%. I say "now" because, in the recent past, I thought it would be cool to breed fancy guppies, long finned white clouds and bettas. In the past, I did this and was able to provide them to LFS for cash or, at least, store credit.

I first chose long fined white clouds. Took some time but I found an importer and paid a premium plus shipping. They were mature and healthy. After several months of conditioning, heavily planted tank and ideal conditions...nothing. They went through all the motions but no fry.

I did a lot of research and found that some off-shore breeders chemically sterilize the fish they sell. I do not subscribe to conspiracy theories but, with ten adults, and ease of breeding, there would be some success. I introduced some normal white clouds. They spawned with each other but no long fins were produced. The long fins were "re-homed" to a LFS.

Next, I paid a premium for guppies shipped from importers. Before I realized it, they were heavily inbred and infected with internal parasites. It took a lot to get rid of that. The remaining ones are stunted and will be "re-homed" as they are not saleable.

My final test was proving that my failure to breed bettas as a kid, could be correct with modern methods. I was very successful!

Now I have dozens of maturing juveniles...problem is, I can't find a LFS that will do anything more than "re-home" them. I don't want the hassle of mailing them in the winter or unknowns showing up at my door for freebies. So, the LFS wins again with "re-homing". Fish I give away and they sell to unsuspecting customers.

I have concluded that mine is a hobby. I want community tanks with natural and maybe, endangered fish. If they spawn and some survive, great. These tanks will also be planted. Growing plants is another interesting part of this hobby.

I have no use for glowing, bloated or otherwise deformed fish.

 

[TwoTankAmin]

When I first began working with zebra plecos I asked the person who helped set up the owner of the breeding colony I bought. This person also taught me a lot of what I needed to know to succeed. One of the questions I asked her when I bought the colony was how many generation I could go using only the 13 fish before I needed to introduce new genes. Her answer was at least 5.

Now considering a reasonable time for a generation of zebras is about 3 year maybe a tad more if you want to work with mature females who should produce the most eggs. So, here we would be talking about 15 years. However, I worked in unrelated fish a couple of times since I acquired the breeding group in Apr. of 2006.

I also work with L173 which takes even longer to reach maturity. I was very lucky to get wild caught fish. So I was able to offer true F1 from wild offspring. To date I have only heard from my first buyer that his fish spawned.

One of the more interesting papers I have run across in all of the papers I have read dealt with spawning in larger groups of fish. The paper indicate that in a group of 100 fish, most of them will not be spawning. Only a limited number would be doing so. The point of the paper was to show that the actually genetic diversity one might find in a group is lower than the absolute numbers would suggest. I have always preferred to work with small groups with plecos. I target a bare minimum of 6 fish and prefer closer to a dozen. I have had bigger groups as well. I know that it is only to top few that do all the spawning. Pecking orders matter.

An early 20th century linebreeder, Dr Myron Gordon, crossed platys and swordtails and realized it triggered skin cancer in the offspring. Evolution leaves us and them with the same sort of Melanoma, and the Xiphophorus family has now been heavily researched to teach us a lot about ourselves.

Here is the most interesting part of the above. For research purposes these fish need to be genetically identical so the research can standardize, So many decades after this Xiphophorus research center was founded the fish used today are identical to those original fish. Their genetic map is one of the more researched ones out there.It has been an essential component in certain cancer research.
Xiphophorus Genetic Stock Center

In less than a year, using a strain of platyfish Gordon had inbred for 16 generations of brother-to-sister matings, making them as genetically alike as identical twins, Kallman was able to begin his pioneering experiments on the immune system of fish.

edited for typos