Reptile & Amphibian Forums

Just out of curiosity, (I am new to ball genes) If spider is dominant then why do I see het. spiders for sale? If it is dominant then there should be no hets....
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.1 Snow Corn "Hope"
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
.1 MO Locale Black Ratsnake "Molly" (Flogging Molly)

"Have you ever tried simply turning off the T.V., sitting down with your kids... and hitting them?"

if you want to cross the spider with a recessive gene, then you make a spider het for that gene. spider het for albin, spider het for ghost etc.....

There are no spider hets (het for the spider gene) - there are however spiders het for other morphs (eg. spider het pied).
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Tosha
JET Pythons

Ok, so then if someone says that they have a ball python het for spider they are full of crap correct? Also, so then what does spider to normal give you? Spiders?
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.1 Snow Corn "Hope"
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
.1 MO Locale Black Ratsnake "Molly" (Flogging Molly)

"Have you ever tried simply turning off the T.V., sitting down with your kids... and hitting them?"

"Ok, so then if someone says that they have a ball python het for spider they are full of crap correct?"

Pretty Much

"Also, so then what does spider to normal give you? Spiders?"

Odds are half the clutch would be spiders and half would be normals. Sometimes you get good odds some times you get bad odds but what if boils down to is each egg has a 50/50 chance at being a spider.
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Tosha
JET Pythons

See RatliffReptiles’ post below for the scoop on het spiders. Just because hardly anyone in the ball python community uses het properly doesn't make the majority any less the ones full of it on this subject.

"Also, so then what does spider to normal give you? Spiders?"

Odds are half the clutch would be spiders and half would be normals.

This points to my main argument as to why I believe it would be less confusing in the long run if we would start using the real meaning of het - having an unmatched pair of genes. If you remember that a spider has one spider mutant allele and one normal allele of the gene at the spider locus (i.e. is a het for the spider mutation) then it's easy to see why it's offspring with a normal have a 50/50 chance of getting that one copy of the spider mutant allele. Now consider a more complex dominant type cross like pewter X killer bee and it gets even more important to break the breeding down to genotypes. These “fancy” crosses are going to become more common as more people can afford multiple mutant ball pythons so the confusion to understand genotypes in spite of the current common usage will pay off down the road.

I knew someone was going to jump in with this - yes - spiders are hets as they have an unmatched set of genes.

However no one uses the term "spider het" because they are spiders and from a buyers/seller standpoint a morph is worth more than a "het".

Also - almost every time you see anyone using the term het for spider, mojave, pastel, etc. they are being deceiving. By not referring to visuals as hets it clears up some of the confusion and scamming that goes on. JMO.
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Tosha
JET Pythons

The term 'het' in the reptile morph market is often used incorrectly. As far as I know all spiders are actually het or heterozygous for the spider trait (the heterozygous form is a visible mutation). I believe a homozygous spider genotype is lethal but that is for another discussion. Spiders are not refered to as a 'het' in the ball python morph market despite it actually being the correct description. If the spider trait is also combined with some other trait, such as albinoism or axanthic, then the spider would be refered to as 'spider het albino' or 'spider het axanthic'. Herpetoculturists have inadvertently re-defined many genetic terms for ease in understanding.

Brad Ratliff

in correct genetic terms, there are animals that are phenotypical and genotypical.

phenotypically means the animal is a visible mutation

genotypically means the animal has the genes to produce a visible mutation.

given that, i agree with you in the fact that spiders are all het for spider. i also agree with the fact that spider to spider breeding is a lethal gene. that might explain why some spiders "spin" their heads.

on the other hand, since two normal animals will not produce a spider, i would say that the gene is dominant. a dominant gene is superior to being heterozygous. but your theory works in the fact that a spider to a normal makes 50/50 spiders just like albino to normal makes 50/50 hets. the spiders are just visible hets. in this case breeding two hets together is not a good thiing such as it is with a recessive gene.

however, the story is different with mojaveies, fires, lessers, and butters. these animals i would say are visible hets for "leucistic" (oh no, another can of worms).

pastels are visible hets for super pastel.

i thinkn we agree in a round about way. all is good, and no reason to argue over small beans.

"in correct genetic terms, there are animals that are phenotypical and genotypical." Kinda true, for each animal there is a phenotypical desription, and a genotypical description.

"phenotypically means the animal is a visible mutation" This is kinda true, actually phenotype means "observable" traits. The new trend in genetics is to rate them according to Macro Phenotype and Micro Phenotype. Macro being observable without in depth testing at the small level. Micro being observable with in depth testing (microscopes etc).

"genotypically means the animal has the genes to produce a visible mutation." Actually, genotype refers to the genetic makeup of the animal. It describes the combination of multiple alleles at each locii on each chromosone.

"given that, i agree with you in the fact that spiders are all het for spider." This is true, unless there are some homozygous spiders out there, that have yet to be proven( a difficult thing indeed).

"i also agree with the fact that spider to spider breeding is a lethal gene. that might explain why some spiders "spin" their heads." I lead in the direction of lethal as well, but I believe that the "spinners" are heterozygous as well, linked with Spider gene, or the result thereof. Spider X Spider (both hets) = 1 homozygous, two heterozygous, and one normal, but if you are saying the homozygous form is more than likely lethal i agree.

"on the other hand, since two normal animals will not produce a spider, i would say that the gene is dominant." It is theoretically possible for two normal looking animals to produce a spider, if there is an allele involved that masks (is dominant to the spider trait) said trait. Very convoluted, but there it is. The only thing we can say so far about the method of inheritance for spiders is that it is, "a dominant type of inheritance". Not that it is dominant per se, but that so far it looks to be dominant. If the mutation ever proves to be lethal in the homozygotes, then we can call spiders "Co-Dominant" .

"a dominant gene is superior to being heterozygous. but your theory works in the fact that a spider to a normal makes 50/50 spiders just like albino to normal makes 50/50 hets. the spiders are just visible hets. in this case breeding two hets together is not a good thiing such as it is with a recessive gene. " Alot of misinformation here, so I'll try and clear it up. A dominant gene is not superior to being homozygous, it just means that the phenotype for the heterozygous and homozygous forms is the same (Genotypically different, Phenoytpically the same). Yes, most spider are indeed visible heterozygotes. Breeding two hets in this case is no different than breeding two recessive hets together, only difference is that you can visibly tell the difference between a normal, and a het. The lethal theory for Spiders has not been proven, and it will probably be a long time before it is, and with the way things stand now, it doesn't make sense to do any Spider(het) X Spider(het) breedings, since the money is in the visible spider hets. As for the spider(het) X normal resulting in 50/50 spider/normal you are correct. But a Albino (Homo) X normal will result in 100% of the clutch being heterzygous for Albino, not 50/50 as in the case in het x het.

Thanks,
Dan

The Spider is a visual het like a Pastel.David