i have a predisposition to never want any spiders or morphs

[Seven-Thirty]

This is not entirely correct. First complete dominant is to incomplete dominant as poisonous is to venomous.

Dominance is not only that the heterozygous from looks just like a homozygous form, but more importantly you will have a homozygous which is phenotypicaly identical to a heterozygous that will produce 100 percent heterozygous animals when bred to an animal not carrying that gene. In this case if spider is a dominant morph you should be able to produce an animal that appears to be a spider but will produce no non spider offspring. Following if the homozygous is in fact lethal there is no way to prove Dominance short of finding and preforming genetic testing on a dead homozygous embryo.

I know the terminology of co-dominance and incomplete dominance is wrong but the way it is used in the reptile hobby they are used interchangeably. You also basically reiterated what I just said with different terminology. i.e. super spider that looks the same as a normal spider aka same phenotypes. I was just assuming that people asking the question about super spiders know what super means so I didn't bother explaining it. My bad. XD

If the homozygous is lethal it is automatically not a dominant trait. Every homozygous lethal is technically a co-dominant/incomplete dominant due to the different phenotype. i.e. death. For example, munchkin cats have a homozygous lethal. Homozygous munchkin cats fail to even gestate so performing genetic testing on that is out of the question but it is known that it is a homozygous lethal.

So if you produce a 'super spider' will that result in a slug, an infertile egg that looks good, or does it develop into a white snake and just perish before it hatches?

In theory yes. Any of those outcomes would happen to be the case except the infertile egg part. What seems to usually happen is that the egg will be good but will die before hitting even the embryo stage. It's rare to get the white snake in general in that pairing.

[AntTheDestroyer]

I know the terminology of co-dominance and incomplete dominance is wrong but the way it is used in the reptile hobby they are used interchangeably. You also basically reiterated what I just said with different terminology. i.e. super spider that looks the same as a normal spider aka same phenotypes. I was just assuming that people asking the question about super spiders know what super means so I didn't bother explaining it. My bad. XD

If the homozygous is lethal it is automatically not a dominant trait. Every homozygous lethal is technically a co-dominant/incomplete dominant due to the different phenotype. i.e. death. For example, munchkin cats have a homozygous lethal. Homozygous munchkin cats fail to even gestate so performing genetic testing on that is out of the question but it is known that it is a homozygous lethal.



In theory yes. Any of those outcomes would happen to be the case except the infertile egg part. What seems to usually happen is that the egg will be good but will die before hitting even the embryo stage. It's rare to get the white snake in general in that pairing.

The hobby using a term a certain way does not make it correct. My point was exactly that if it is lethal you can not prove which forms of dominant it is. There are still well known people working with the gene saying that it is not lethal, so I am not convinced it has been proven to be lethal.

[Seven-Thirty]

The hobby using a term a certain way does not make it correct. My point was exactly that if it is lethal you can not prove which forms of dominant it is. There are still well known people working with the gene saying that it is not lethal, so I am not convinced it has been proven to be lethal.

The fact that it is lethal means that you can prove that it is at least not dominant. Dominance means that the phenotype, as you previously mentioned, is the same whether in heterozygous or homozygous forms. We know that spider is not some weird anomaly that can't have a super due to the fact that black head spider is a super and logically a homozygous form does exist of the spider mutation. Unless there has been some weird backwards bad luck in the past 20 years of who knows how many breedings that the super spider has not been found, logically it would mean that the super spider is a lethal super/homozygous lethal.

Well known people working with the gene include Kevin McCurley who I idolize but does tend to say some things that make no sense at all such as the hidden gene woma granite thing. Kevin believes that the super spider doesn't exist at all and that it isn't lethal either. It just simply does not exist which makes no sense biologically speaking. The best way to prove this once and for all is to do a blackhead spider to blackhead spider pairing and record what comes out. There would only be three possibilities from such a pairing. Super black head, black head spider, and super spider. If you never hatch a spider or something that isn't a super black head or black head spider, then it is 100% confirmed that the super spider is a homozygous lethal. Just because well known breeders say it's not lethal doesn't mean it actually is so given the evidence that has surfaced in the past 20 years.

[AntTheDestroyer]

The fact that it is lethal means that you can prove that it is at least not dominant. Dominance means that the phenotype, as you previously mentioned, is the same whether in heterozygous or homozygous forms. We know that spider is not some weird anomaly that can't have a super due to the fact that black head spider is a super and logically a homozygous form does exist of the spider mutation. Unless there has been some weird backwards bad luck in the past 20 years of who knows how many breedings that the super spider has not been found, logically it would mean that the super spider is a lethal super/homozygous lethal.

Well known people working with the gene include Kevin McCurley who I idolize but does tend to say some things that make no sense at all such as the hidden gene woma granite thing. Kevin believes that the super spider doesn't exist at all and that it isn't lethal either. It just simply does not exist which makes no sense biologically speaking. The best way to prove this once and for all is to do a blackhead spider to blackhead spider pairing and record what comes out. There would only be three possibilities from such a pairing. Super black head, black head spider, and super spider. If you never hatch a spider or something that isn't a super black head or black head spider, then it is 100% confirmed that the super spider is a homozygous lethal. Just because well known breeders say it's not lethal doesn't mean it actually is so given the evidence that has surfaced in the past 20 years.

I mean there have been reports of Bigfoot for more than twenty years but that doesn't make him real. I am just kidding as that is definitely not a good comparison. My point is that it all anecdotal evidence describing a pretty complex genetic situation, so it doesn't seem pertinent to draw definite conclusions on. I definitely never said it was recessive. The spider blackhead project is an interesting idea academically, but from a breeding perspective it is a bit of a waste genetically. Seems like a lot of work to end up with normal looking animals, a few super black heads, and possibly a spider looking animal.

[Seven-Thirty]

I mean there have been reports of Bigfoot for more than twenty years but that doesn't make him real. I am just kidding as that is definitely not a good comparison. My point is that it all anecdotal evidence describing a pretty complex genetic situation, so it doesn't seem pertinent to draw definite conclusions on. I definitely never said it was recessive. The spider blackhead project is an interesting idea academically, but from a breeding perspective it is a bit of a waste genetically. Seems like a lot of work to end up with normal looking animals, a few super black heads, and possibly a spider looking animal.

It's not a complex genetic situation at all. Homozygous lethals are everywhere, even in mice. You can't disregard how genetics works, it's set in stone. I also don't understand where your point about recessive came from but that's a moot point.


The blackhead spider project isn't a waste genetically at all. It's not a waste to make super black heads nor is it a waste to make normal looking supers. The genes that make that normal looking snake, spider and black head, are still nice genes to have around and it's a super. Supers are always a welcome addition to my collection. It would also put to rest the super spider debate once and for all.


Also, technically everything in this hobby is anecdotal evidence but we've been able to accurately predict to a T what will happen when you put X and Y together and if XY is allelic or not based on, again, breedings. Imagine how amazed everyone was when the first allelic combo was made, which if I recall was the super stripe. No one would have known what was going on. It's through breeding and taking note of what comes out and using that information to predict what will happen with breedings, do we start to understand what is going on just as Gregor Mendel did many years ago.