breeding from same batch

just wondering if its ok to breed bristlenose reared from the same batch

Breeding brother to sister has the potential of poor and weak offspring with higher fry mortality. Unless your breeding fish for a specific trait then your always better breeding unrelated fish.

Jim is right

Breeding brother and sis is often a recipie for disaster. Because bristlenose are so inbred already by continuing to do it you are risking loosing the whole batch. Often they will hatch but shortly after they will start to die off, more often than not leaving you no survivors. Best to try and swap one of your mature fish with another fish keeper

So there's a noticeable difference in breeding brother and sister than an unrelated pair? What about cousins? How far the relation have to be to make sure maximum survival rate (gene wise) for the fries?

hehe fries

just had a classic image in my head of all these mcdonalds fries swimming around my tanks hahahahaha

there might be a noticable difference. The thing is you have no idea how inbred your particualr fish are already. if you have two wild caught siblings then you could prob get away with a few generations of inbreeding, but most aquarium stock are already heavily inbred meaning that you risk loosing the whole lot.

with siblings there is a, conservativly, 1/8 chance they will end up with the same copy of a gene. doesnt sound too bad but when you consider there are 1000s of genes that make up a fish and it only take two copies of a single bad gene to kill a fry then you can see why it has become such an issue.

crossing cousins means the chances go out to 1/16 of getting the same gene.

there is no gaurenteed level of relatedness that will produce viable offspring. sometimes you get unlucky and two totally unrealted parents will be genetically uncompatable, just like in humans

your safest bet is to see if you can swap on of the breeders over. I know that I do this on a regular basis. I will often swap one of my experences breeders with an younger male. People seem to like this as they get a proven breeder and i get some fresh meet to train up and we both get a new bloodline.