Pos het or not pos het?

Hi guys if I breed Pastel 66%het pied X normal. Is correct to say about the result :pastel (or normal) poss het pied? Thanks

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Yes and no. A 66% or 50% het is either Heterozygous or it is not. So an unproven 66% Het is not necessarily heterozygous for that mutation. If it doesn’t carry the gene, then calling offspring pos het would be specifically dishonest. Since you can’t be sure just list the parentage of the clutch and explain the situation if the buyer doesn’t understand the simplified genetics we use in the hobby.


There was a very long and spirited discussion on this matter a year or so back. Basically it falls into two camps: those that believe that, unless the “poss het” animal is proven, it is unethical to use half divisions of that on subsequent offspring, versus those that believe the use of half divisions is perfectly fine.

I am firmly in the prior camp.


I remember this conversation, and am also in the “it’s unethical to call them pos hets” camp

I think this was it… Possible het input to morph calculator


I like to include the knowledge of poss hets just so that a buyer can know that somewhere down the line this snake might end up being het, but I only do it for record keeping. More of a ‘these are the genetic influences of the parents for transparency’ and less ‘this snake is a pos het because its parent was a pos het.’ In that case I just include the pairing in the description, that way the buyer is informed but you’re not actually claiming the animal is pos het when the parent hasn’t been proven one way or the other.