Quote Originally Posted by kc261 View Post
Well, the reason I think it is more likely that homozygous spiders exist than that homozygous spider is lethal is because I've heard credible rumors of the first, and nothing but speculation of the 2nd. There is a member on this forum who claims to own a spider that has only been bred a fairly limited number of times, but so far has produced 100% spider offspring. I have absolutely no reason to doubt that claim. I've also heard 2nd or 3rd hand of some others who have been bred quite a bit more and still throw 100% spiders. Now, I realize this proves nothing, which is why I said I believe this possibility over the other one, rather than saying this is a fact.

It would be an easy enough thing to get pretty convincing proof if either one big breeder or a group of smaller breeders would pair known het spider to known het spider (or spider combos would work as well of course), and document the offspring ratios. 3/4 spider means it is non-lethal dominant with no visible homozygous form, 2/3 spider means it is co-dominant with a lethal homozygous form.
The nature of the problem of proving a mutation homozygous lethal is that it's much harder to produce credible evidence of something not existing than that it might exist.

I'll have to find and re-read the evidence from the keeper here. I didn't doubt at all that the info was accurate; my only question was if it was enough to be very significant. I remember when I first read it just didn't seem like enough spiders in a row. I also remember there where a lot of dead eggs which should be randomly distributed between spiders and non spider offspring so really shouldn't matter but it did make me wonder if somehow the dead eggs tainted even the streak of spiders that was presented. It would have also been nice to know if that male spider even had the chance to be homozygous by having both spider parents. Hopefully that male will be able to produce some more full term eggs this year.

I think I've only heard detailed results from a single spider x spider breeding so too small to be significant that 1/4 of the eggs where undersized and didn't hatch.