I believe HG Woma is technically an example of a homozygous lethal ball python mutation. The pearls hatch but apparently don't live to maturity.

NERD has been consistently opposed to any label with the word "lethal". I can understand because you can't get much more negative but as I've regularly pointed out "homozygous lethal" doesn't really say anything negative about heterozygous spiders and their many beautiful combos. Still people jump to incorrect conclusions when you talk about spider possibly being homozygous lethal like that spider X spider can't produce any viable offspring (3/4 of the clutch should still be good) or that you would have to see the problem homozygous spiders (they might not hatch) so maybe that's why NERD is saying spider can't be homozygous lethal.

Quote Originally Posted by OhhWatALoser View Post
...know what else we haven't seen homozygous of? Avalanche, Banana, Black Belly, Black Head, Black Lace, Calico, Champagne, Coral Glow, Daddy Gene, Desert, Ember, Epic, Fader, Granite, Het Highway, Spark, Josie, Marble, Napalm, Orange Glow, Philistine, Reaper, Shatter, Spector, Sugar, Whirlwind, Whitesmoke, Woma. Are they all co-dominant also since there is an absence of homozygous forms of them, or maybe it's just not proven yet.....
I've not followed all of these but I do remember RDR doing a platy X platy breeding and producing a female normal looking that should have been a super daddy gene (aka hidden). Didn't hear if it grew up ok and bred to prove its expected genetics. Should have been able to breed it to a homozygous lesser and produce 100% platy.

At this point I sort of take a negative agnostic view. I would say that any morph without a proven viable homozygous example is potentially homozygous lethal and unknown if it's dominant or co-dominant (on a like subject I would say any morph without a proven producing female is potentially female sterile). How likely it's just a case of not enough time to prove one out versus an actual homozygous lethal situation depends on how long the morph has been out and how many people are working with it. I understand the first spider was imported over 20 years ago and many many people are breeding spiders so the lack of a public proven homozygous spider is conspicuous.

I've also heard the occasional claim of a potential homozygous spider having produced a string of only spiders. Most of these are 3rd party reports but of course I'd love to hear more info on them rather than just assuming when they don't come back with updated info that the string was eventually broken.