Is "Selective Breeding" and "Inbreeding" the same?

[Endlerama]

Recently, I posted a question regarding a response in a betta related post regarding this, but got no reply, so I figured I'd try to start a fresh thread on it...

In the post, it was stated that Bettas are largely inbred, that Petco type ones are unhealthy for this reason, and that one was better off trying to get one from a fish auction from a breeder.

However, I had always thought that breeders, in their desire to create the most uniformly colored fish they can, routinely perform "selective breeding," largely keeping the gene pool as homozygous as they can to achieve this.

While I certainly don't doubt that breeder's Bettas are likely in healthier shape due to better care in diet and water conditions, I'd be apt to think that the pet store bettas are a better fish due to a more heterozygous genetic makeup.

So I ask again. What's the differences between Selective Breeding and Inbreeding (answers in common English please! :D )

[MrGoodbytes]

I'm pretty sure that selective breeding and line breeding are techniques used by breeders to fix a strain that they have developed. Usually this is something like breeding the father to the daughter.
Inbreeding is just a free-for-all where no particular fish are selected and no new genetic stock is introduced. That is one reason why a lot of store-bought guppies don't breed true (same colours/finnage as the parents), because they are a mix. After several generations, the genetic integrity of the fish declines and more runts are born that have deformities and problems.
I'm pretty sure I got that right, anyone else have anthing to add?

[pinballqueen]

Well, as a child of a dog breeder and a former cat breeder...

"Selective" breeding is when you choose two animals that exhibit the "perfect" qualities that you wish to bring out. This does not mean the two animals are related in any way, in fact, usually this means that they are not in fact relatives, just both exhibiting the desired qualities.

"Line" breeding is a form of selective breeding that involves breeding mother to son or father to daughter in order to intensify a desired trait. In this situation, while the desired trait is usually brought out in a very striking manner, there is the possibility of creating other genetic disorders. Many of the rarer dog and cat breeds are bred initially in this manner to bring out something you want, such as a bulldog's flat face or a sphynx cat's hairlessness... after the animals breed true, and continue to do so after several generations, line breeding is not nearly as common a practice, because if continued, it will cause many of the undesirable affects associated with inbreeding.

Inbreeding is an entirely different matter than selective or line breeding. It is something that is much less responsible, allowing sisters and brothers, as well as original parents to breed freely (or breeding brother/sister on purpose), and never introducing new stock to the genetic line. This happens in many home aquariums with live-bearers, because the breeding cannot be monitored easily. This usually results in deformities, and eventually the sterility of all new stock produced.

Hope this clarifies things....

[JeffP]

I believe that selective breeding, line breeding, and inbreeding are basically the same thing.

Line breeding and in-breeding are when related fish are mated to each other. I suppose the degree to which this is controlled could be referred to how selective it's done. Breeders will cull those fish not exhibiting the qualities they are after and not let them breed.

Periodically introducing an unrelated fish is refered to as outcrossing. This is done to enhance particular characteristic(s) in a given strain of fish or to improve vigor which progressively declines with repetetive line/in breeding. If this is done too often, the breeder can loose "control" of his strain.

Randomly mating fish who possess desirable characteristics does little to improve the percentage of offspring (if any) who will possess the desired characteristics.

[pinballqueen]

Well, it might mean something different for dogs and cats than it does for fish, then....

I bred persian cats for years, and my parents have been dog breeders (miniature pinschers and dobermans) for as long as I can clearly remember.

My definition is taken from akc and cfa regulations, so it might be different when talking about cold-blooded creatures....

[wetmanNY]

I thought pinballqueen nailed it on the first pitch, selective breeding being the broadest category. But JeffP's description of what "outcrossing" is adds a further point. Outcrossing does reduce the percentage of F1 offspring with desirable characteristics, in favor of preserving genetic vitality further down the line.

[Mr.Jingles]

yeah...pinball got it good.

[RTR]

I agree w/pinballqueen's definitions and examples, they are just as correct for fish as for dogs and cats, or people. Also agree that the outcrossing comments are valid, and that the practice is valuabe to strain or breed development.