In all other animals inbreeding has terrible results. Sure, it may seem good for the short term but in the long term it creates a whole whack of issues. This is widely understood when it comes to breeding mammals. I want to know why people feel this does not apply to fish... and my sister, who is getting a phd in fish genetics, wants to know too.
Genetic diversity strengthens the animal. Inbreeding does not.
well you should not only breed a betta sibling pair for many generations. you should introduce new genetics into the line. most of the time when you are breeding bettas you are goin for one trait. say i am breeding a royal blue butterfly hm male to a turquoise female hm. i am aiming to breed towards a turquoise butterfly hm. then if i get a male and female out of that spawn with turquoise coloring with an even butterfly pattern then i would breed them to get even more that look like them. thats what i meant.
No offence but I fail to see why mernin's post was confusing, lol :/...considering your sister has or is getting PhD in the subject, you'd think she'd know about selective breeding.
Essentially bettas are bred for certain traits...There are 3 kinds of bettas that are bred (That I've seen around either aquabid or the internet): Show type, Consumer/hobbyist type, fighter type (although sad, it still exists).
For the show type, severe inbreeding is because you breed back all of the "good" traits of the fish, i.e. perfect finnage or colour. Since the breeder knows what they want in a fish, they selectively breed and re-breed fish with the ideal trait that they are looking for. Fighting types are bred for aggressiveness and/or agility and fighting habits. Hobbyist types are bred to be sellable to people like us...so pretty colours instead of perfect fins or other traits.
Theoretically, plakat bettas are bred as "fighters" due to their short, out-of-the-way fins.
As for the morals of doing this...simply: Money? Bragging rights? That's the more difficult question that would have multiple answers
I'm sure other "purebred" animals are also genetically weaker than mutts and mixes, but there are people in this world who would pay a pretty coin for a purebred dog if it were available, regardless of potential health issues.
Selective breeding is one thing. Inbreeding is a whole 'nother ball game, imo. Inbreeding and line breeding are two different things.
I understand why it's done but I'm amazed that people think this will create better fish in the long run. Horse people no longer do it (though they do line breed), cat people don't do it, even dog people are starting to see the light. Those German Shepards who can barely walk because their butts are so low to the ground? That's the direct result of inbreeding.
In today's society we know the dangers of breeding siblings and parents to siblings. So why do it? I guess, as you said, money is the main factor.
And my point, in asking her how, was that it is common knowledge that the negatives of line breeding far outweight the positives (at least from a genetics point, but perhaps not from a money point of view).
Last edited by Super Fish; 07-21-2011 at 10:19 PM.
It's not so uncommon in fish breeding because many responsible breeders cull out any undesirable mutations or deformities that crop up, thus removing those individuals from the gene pool.
Inbreeding and linebreeding are simply tools used by breeders to develop a consistent type or line. Yes you could use selective breeding, but it's much faster to simply breed sibling to sibling/ offspring back to parent to 'fix in' certain traits. Yes you will get some genetic defects showing up in certain individuals because of the doubling up of recessive genes, but these should either be culled or sold into pet homes and not kept on as breeding stock.
I do agree outcrossing is important, and I believe someone said either on this forum or another, that you need to outcross once you reach the 6th or 7th generation of fish. However inbreeding and line breeding both have their role, and shouldn't be simply disregarded as a greedy grab for money.
@Super FIsh; I understand your concern about the negative effects on inbreeding. And I also agree that we humans always over manipulate and over exploit nature. But without inbreeding, betta's form would remain as they were; VT, long finned round tail, and round tail PK.
Keep in mind that these are fish, not mammals, thus are more tolerant towards inbreeding. OK, so we have the traditional VT,RT,and PK which we breed extensively. Then one day a batch of fry mutated into a delta tail (F1). If we out breed to a traditional form, we will lose the mutation. So we breed siblings and get more delta tails (F2). Then cross cousins and further cross breed to either VT or RT and take the deltas and breed those to F2/F3. And so on until we get a dominant trait that will breed true.
We don't inbreed for ever. I think it has been confirmed that it is positively safe to inbreed for 6 generations, some say more. But I never go that far. I usually cross after F3, sometimes, if necessary F4. Believe me we avoid creating genetic defects. Take the DT for example, it is not advised to inbreed them or even breed DT to another DT because they will create genetically defected offspring.
Inbreeding is not advised amongst our local breeders. But it is often necessary to achieve our goals. We often can't avoid it to create new traits, both in form and color. And breeders often exchange their collection to out cross their own line.
I hope this answers your question - though we inbreed, yet we stay in the safe limits........ (sorry for the long post)