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Okay so this might have already been talked about but I was curious as to why the spider is a codom if there is no super spider? can someone please help me understand this.

That's because the Spider is not co-dom, it is a dominant morph.

Dominant morphs do not have a homozygous form (super) that is visually different from the heterozygous form (non-super). With that said, I am not aware of any Homozygous Spiders being produced to date.
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http://www.GilbertBoas.com/
http://www.BoaList.com/

They are co-dom because when bred to a normal only half the clutch is spider. If they were dominant the whole clutch would be spiders.

The hypo gene in boas is co-dom, but if you breed two hypo boas together you will get some dominant hypos (super hypo). You can't tell which are the supers until you breed them to a normal and get all hypos or if you breed two known supers together all the babies are supers.

I wonder if the spider is the same way???
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Randy and Michelle
Art In Scales
(719) 439-4199
info@artinscales.com

"They are co-dom because when bred to a normal only half the clutch is spider. If they were dominant the whole clutch would be spiders."

This is a common misuse of the terms co-dom and dominant. What you are really talking about is heterozygous and homozygous genotypes. Spiders produce on average half spider clutches because they are heterozygous for the spider gene - they have one spider mutant version and one normal version of the spider gene so each baby has a 50/50 chance as to which it will get from a spider parent. If there ever is a homozygous spider then it would produce all spiders because it wouldn't have a normal version of the gene to give.

Until a homozygous spider is proven we can't know for sure if the mutation type is co-dominant or completely dominant. The difference in the mutation type depends on how the homozygous spider is compared to the heterozygous spider. If both homozygous and heterozygous spiders are mutants but are the same then spider will be proven dominant. If homozygous spiders are different mutants in some consistent way (like looking different or not hatching) then spider will be co-dominant. The mutation type does not change depending on which mutant genotype you are looking at but is defined by the difference or not between the two.

After 8 years of captive spider production we still don't have a public proven homozygous spider.

I guess I should have done some research before I opened my mouth. I thought it made sense the way I said it, but you are right. If there is no difference between the het and homo forms they are dominant.

I still wonder if there could be a super spider that when bred to a normal would make all spiders like the super hypo boa.
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Randy and Michelle
Art In Scales
(719) 439-4199
info@artinscales.com

Depending on where you researched it might have taught you to use "co-dominant form" and "dominant form" for heterozygous and recessive. It's a very common mistake in the ball python world for years now

I know Kenny from Nerd responded to a post regarding the Spider's genetics a week or two ago stating that Spiders are not homozygous lethal. It seemed to be a somewhat empirical statement by someone you would think should be in the best position to know the facts?

With this being true, one would think that, in eight years, we would have seen reports of either a clutch consiting entirely of Spiders, or someone would have wanted to (one would think) have laid claim to producing the frist Super Spider's and this person would have then have revealed it with pictures up on the forum, or better yet, at a large reptile show for maximum impact...

This would seem to be the case, unless, it made more sense for someone to keep the existance of a Super Spider under wraps and undefined. This would allow someone to gain a huge head-start and have the advantage of being able to discreetly roll the Super Spider genetics into other morphs, thereby creating something that would be totally unique and would not be readily identifiable, especially if people where unaware what they where looking for in the snake. This would then dictate that anyone that wanted this "unique" mutation would be forced to go to the one and only source for it. The seller would then be able to charge whatever they felt was warrented or obtainable. In addition, by first building up a supply, and then only selling the females of this mutation at first, someone could then delay, for several years, the ready supply of this morph, and thereby control its value and the direction in which it is crossed into other mutations.

This senario would be especially plausable, if contrary to what one would imagine it to look like, instead the Super Spider turned out to be a less than dramatic morph visually. If the Super Spider turned out to be a dull and boring or not much different than the original animal, maybe keeping it on the down low and only using the genetics to enhance and create something alot more visually stunning might make more sense than trying to sell an ugly Super on its own? Furthermore, there was a time when the existance of a Super Spider might have gone a long way towards bouying the price of regular Spiders, but the supply has been high on these for quite awhile now, and many large female Spiders already exist. At this late date (I.M.H.O.), the existance of a Super Spider would no longer be able to impact the value of the regular spider in a significant way.

It is also the case (I believe) that with the talk of the Spider as possibly being homozygous lethal, this may have the effect of causing many who have breedable sized female spiders to pass on breeding them for a Super form. Who is going to want to breed their 2000 gram female spider to another spider, only to have the potential to have all the babies die? Why do this, when you can create some guaranteed bees or other high dollar morphs instead?

It is an odd situation with Spiders that will undoubtedly (hopefully...) be made clear one day.

Calico's are another one that have this elusive "X" factor involved with them. I find it odd that any speculation about the Calico's genetics is met with a very intense response. I havent seen anything about a Super Calico being produced again this year, it has gotta make you wonder how long the elusive "Super Calico's are coming this year" story can go on with no definative resolution? If the Spider is any indication, I guess speculation regarding Calico's can go on for at least eight years - huh?

Very interesting stuff ain't it...

"It is also the case (I believe) that with the talk of the Spider as possibly being homozygous lethal, this may have the effect of causing many who have breedable sized female spiders to pass on breeding them for a Super form. Who is going to want to breed their 2000 gram female spider to another spider, only to have the potential to have all the babies die?"

If spider where homozygous lethal it would only effect the on average 1/4 of the spider X spider clutch that inherited the spider mutation from both parents. The heterozygous spiders and the normals in the clutch would not be affected. I think it's the wide misunderstanding of what homozygous lethal means that leads to the vigorous defense that it isn't possible. It's really not that big of a deal, especially since the heterozygous version and its combinations more than justify the current pricing. If it where known for sure to be homozygous lethal then people would just not breed spider X spider which is really no change from what is happening now.

The only way to know for sure that spider isn't homozygous lethal would be if a homozygous spider where proven through breeding. While "proven" is open to personal interpretation I don't think it at all likely a desirable homozygous spider would be hidden for marketing purposes. Now an undesirable one might, but again, at this point there really wouldn't be much incentive to. We are probably just up against the very difficult job of proving something by its absence.

As Randy stated, your post is an all too common mistake. Not your fault, there is so much wrong information out there.

With Hypo Boas it is probably the worst. They are a Dominant mutation. Dominant means that the Heterozygous and Homozygous forms have the same phenotype. That's why in a Hypo X Hypo breeding they are possible Supers.

Snakes are either Heterozygous or Homozygous for a specific trait. If you keep this in mind you'll never fault. Mutations are either Co-dominant, Recessive, or Dominant.

A Super aka Homozygous isn't a Dominant form of a Co-dominant morph, Super just denotes Homozygous. If it isn't a super it is heterozygous.

If you go to nearly any boa forum, or show where a vendor is advertising Hypo boas, or designer morphs including Hypo, you will likely see someone calling a Boa Potentially Dominant. That is plain wrong, what they have are possible Supers or possible Homozygous if you want to get away from herper slang and go with technical terms. The Hypo morph is dominant.

I have found that generally these mistakes are not made with BP morphs for some reason.
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http://www.GilbertBoas.com/
http://www.BoaList.com/

Thanks, I don't hang out on boa forums and didn't know we aren't the most messed up on this subject.

If we had a proven dominant morph like the boas we would probably see more of this confusion.

It seems to all be based on the Hypo morph. Especially since both Heterozygous and Homozygous forms are so variable.

Though any morph that shows itself inheritable in the F1 seems to be dubbed Co-dominant even before a Super is discovered. Where the best case would be to say it appears dominant with a possibility of being co-dom.

The source of the error often falls on big breeders incorrectly labeling things on their websites often frequented by new entrants into the hobby, as well as many reptile books with bad info. Guess more people should start with a Biology book, lol.
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http://www.GilbertBoas.com/
http://www.BoaList.com/