Odd question...Inbreeding?

Is it possible with fish? I mean...nevermind...I mean exactly what it sounds like I mean! lol

It can be a serious problem - like everything else, connected to luck. In our small populations of fish, a bad mutation can wipe an aquarium strain out really fast. A lot of our fish were collected in very small numbers to begin with.

As well, with the fancy, 'man-made' forms, the mutation starts with one fish. Then they cross it back with its young, and narrow it down... bad stuff can happen.

The industry also intentionally uses inbreeding disasters - there is a common spinal deformity that causes digestive problems and possibly pain to the fish that inherit it, but it also makes them much smaller, and makes them 'cute' to many. The balloon mutation is classic inbreeding - a deformed, handicapped fish with a way shorter life, but it's big money to the fishfarms.

On the other hand, there are species that seem resistant to inbreeding. A lot of killies come from small natural populations, and they seem to keep going no matter what.

Thank You @GaryE... It isn't that I plan to! I think it is just wrong no matter what species it is. I guess I am worried about my guppy fry reproducing before I have a chance to sex and separate them.

They won't generally breed successfully til you can sex them - the gonopodium has to develop first. It forms before their colours though, so check the anal fins.
Most aquarium fish eventually end up in sibling breeding though. With livebearers, it becomes unavoidable at times. We don't all have a hundred tanks...

PHEW...I won't be looked down upon if it does happen! lol If I will see the gonopodium before colors then I am still good I see fins but no gonopodium's. I would not intentionally inbreed or cross breed for the mutation and "fancy", that is just wrong...maybe breed some odd color combos but that would be the extent