line breeding is good as long as it is done with a sense of responsibility and respect for the fish
Hi, welcome to the forum. Sorry to say though, but what you just said there makes the least bit of sense. >.o
On topic tho, crossing two cichlids from the same batch is like having a brother and sister er, make a child. Whatever problems is associated with humans producing offsprings with their own sibling can be seen with sibling cichlids breeding.
The fact is it's all up to chance. Breeding siblings doesn't always mean that the fries will be deformed, but it doesn't always mean that the fries will inherit good traits either. If the siblings happen to have bad genes in them, that can quickly be propagated, and vice versa. It doesn't have anything to do with 'breeding responsibility' or whatever. It's all up to luck. Even if one chooses what seem to be the best of the batch and breed them, one can get badly deformed offsprings anyways.
That said, breeding two cichlids from different lines has on average a lower chance of producing deformed offsprings, just because of the variability in genetic materials.
However, again, it's all up to chance, and that's what one has to keep in mind when breeding... well, anything really. One can do line breeding and never see a deformity for generations, even if they didn't even try to choose the original parents at all, or one could have chosen very carefully - aimed for the best looking, the healthiest parents, and the offsprings could be as deformed as anything.
The only exception really is if you happen to find a pair with really good 'genetics', and by that I mean they carry little to no unwanted genes, then breeding them would continue to accentuate the good traits, but even then it won't last forever.
