# Tank interbreeding! Offspring breeding with parents?!



## masonv (Mar 27, 2011)

I really wanted to know how big of an issue, if any, is it for offspring to breed with their parents. Or on the other hand, offspring breeding amongst each other. Or any of the following combination of the following:
* father/ daughter
* mother/ son
* brother/ sister
* grandfather/ granddaughter
* grandmother/ grandson
* uncle/ niece
* aunt/ nephew

What I'm really asking do fish not follow the same threory of being interbred (such as human,dogs , cats, ect.).


----------



## dielikemoviestars (Oct 23, 2007)

Doesn't matter much.


----------



## PfunMo (Jul 30, 2009)

I think many of us wind up with that situation. There are almost always some fry in any group who doesn't develop as they should. Whether that is do to inbreeding or not, I don't know. It would be nice if we could all have access to new F1 fish to mix the gene pool more but not practical. I've never seen harm tha I could trace to that.


----------



## Number6 (Mar 13, 2003)

masonv said:


> What I'm really asking do fish not follow the same threory of being interbred (such as human,dogs , cats, ect.).


 Fish follow the same rules as mammals and humans, however this is largely a misunderstood issue and my usual advice to folks is "don't worry about inbreeding with your cichlids. Just cull anything that doesn't look right no matter what breeds with what" .



PfunMo said:


> It would be nice if we could all have access to new F1 fish to mix the gene pool more but not practical. I've never seen harm tha I could trace to that.


I've been harmed by that inaccurate advice, I've harmed others by passing it along back in the day... it's not wise to outcross as you then could be caught in the issue of outbreeding depression.

Back in the early days of cichlids in Canada, I had pairs of A.jacobfreigi
I used to have a really unique breeding room in that I would breed jacobs then sell them as "proven pairs/trios" for large sums of money! I'd grow out the fry and pair up the best, etc. 
Made more money this way than friends were selling fry. From my days on the farm, I 'knew' that one can only inbreed for around 5 or 6 generations and then you had to outcross to avoid hidden genetic defects. Boy was that completely incorrect... I bought some very expensive adult F1 A.jacobfreigi and paired up my best linebred fish with the best F1s. My next batch of fry grew out to be garbage... pure garbage. Of course, I had sold all my breeding adults by that point in time. I had nothing left... I couldn't understand how I had made a mistake! I followed the "right" advice from animal husbandry practices. If it worked with farm animals, why not fish?

Lesson learned... an outcross of a domestic animal is an outcross to something pretty genetically similar (and likely related to my bloodline some short distance back) and one is still breeding tight to breed right. A complete outcross to unknown gene pool "x" is actually a stupid risk. Incompatible alleles, introduction of negative genes, undesirable combo effects, suppression of your "good traits" (and more) can happen.

It turns out, every species on the planet has a balance point between inbreeding and outcrossing that is "healthiest" for the species. Some species inbreed often (Kribs) other outcross very often (shell dwellers) and your breeding strategies have to line up with what is known about each species. The other thing that has been discovered is that females (if given the choice of mates) manage to pick the healthiest male to product the healthiest fry out of any given population. Their programming is better than out artificial selection.

So, what's this translate to? Let your fish pick their mates from a big group in a big tank for the healthiest fry (fewest culls or no culls!) and you won't regret it. I usually mix in some related fry, and then some cousins or second cousins and accept what pairs up.

Try it! You'll be amazed what happens and what males get picked out of your tanks!


----------



## PfunMo (Jul 30, 2009)

I was thinking more for the sake of a natural product rather than line bred fish. Once one has gone off the natural selection by doing line breeding, you are right but at that point you have moved so far from the natural that it isn't really a question of natural any more. When Africans were first brought into the country there were those who wanted to keep them pure but as things go, that argument was quickly lost to the group who wanted to make the most money. Feeding hormones and color enhancing now has combined with line breeding to make a market that is no longer very much like we would find in nature. The fish we used to find in the hobby are gone.

Thinking in terms of conservation normally loses because it is not the money maker.


----------



## Number6 (Mar 13, 2003)

PfunMo said:


> I was thinking more for the sake of a natural product rather than line bred fish. Once one has gone off the natural selection by doing line breeding, you are right but at that point you have moved so far from the natural that it isn't really a question of natural any more.


Linebreeding does not move away from the natural more than any other type of captive breeding program does. An owner's artificial selection could, as could excessive inbreeding, but thats independent of linebreeding.

In my case, I selected for "natural" traits including health and behavior.

Outcrossing to a random F1 would end your bloodline and start a new one but doesn't reverse genetic drift... it could actually be an acceleration of the drift!


----------

