[roadmaster]

Need to select best looking male and female for breeding, look closely for deformities.
Inbreeding (brother/sister,fish from same batch of fry) is more likely to result in more deformities,fewer fry born with each successive batch.
Every now and then introduce new male or female to prevent afore mentioned.
I have bred as many as three generation's to get the one male/female I like,,then select a new male or female not from same batch of current fish.
Is good chance that fishes we buy from store tank's are all from the same hatch,so I sometimes purchase new fish from different source.
Nothing wrong with euthanizing poor specimen's but maybe better to take measures to prevent the need??

 

[roadmaster]

Inbreeding,crossbreeding ,in my view/opinion produces weaker specimen's,fishes with unpredictable physiological problem's,unpredictable behaivor's and physical characteristic's,lower fry survival rates,and weaker fish overall.
What once used to be considered fairly hearty species capable of adapting to wider range of condition's,is increasingly becoming an oddity rather than the norm.
My two cent's.

 

[roadmaster]

Inbreeding of healthy hardy stock does not produce weak or compromised fish.
There are small ponds jam packed with inbred wild sail fin mollies.
Generations upon generations, with no new blood.
Although, any deformed ones will be naturally culled before they even leave fry stage.

It's when something is "hot" and bred to death without culling or a plan, just to get them on the market with a high dollar price tag is where things go wrong.

-Stef*

We shall have to agree to disagree I fear
Your opinion carry's no more ,no less weight than mine.
Just my observation's over the last forty year's in the hobby.

 

[roadmaster]

Well, if culling is not performed, and line breeding,cross breeding,or inbreeding continues over month's with no new blood,then undesireable trait's that may have already been in gene pool will occur more frequently in the fry,thus weakening successive generation's.
Is what I believe is happening with more frequency.
Fish farm's more concerned with turning profit's $$ than producing stronger strain's.