Does anyone else find this annoying...

OMG!! you mean all those Het for Hypo's I just bought are worthless!!

Seriously I feel, the same way as most of you, though I have mentioned that an animal was out of a breeding that produced hypo's. I have Jag carpets and my blood pressure rises a little each time I see an add for Hypo Jags lol..Randy

Originally Posted by Scott Nellis

Ok, I admit that I don't know jack about hypomelonism in boas...but hypomelonism in colubrids is a recessive trait. It is possible to have het for hypo in the colubrid world....hypo honduran milksnakes comes to mind, for example. Also...aren't the terms "hypo" and "ghost" different names for the same trait? Like I said, correct me if I'm wrong on this...but that's how I understand it.

In boas, hypomelanism is dominant and any animal that possesses the hypo gene will display the hypo characteristics.

Ghost is not the same thing as hypo. I believe Ghosts are snakes that are both anerythristic AND hypo (anerythristic is a lack of red coloring and hypo is a lack of dark coloring, which makes ghosts very pale, faded looking snakes). I might not be completely correct there as I'm not an expert on ghosts, but I know ghost and hypo are not the same name for the same snake.

In boas, at least.

Oh yeah, Ravensgait - I don't think it's bad to mention that the normal offspring of a hypo was fathered or mothered by a hypo... but some of those ads out there make it seem like "hypo sibling" is something different than a normal and that's different than mentioning that a parent was a hypo.

Hey Lauren I'm curious, where did you see these adds?? Are they on k/s??

There are some right here on Fauna (one within the last week). But mostly on KS.

The simplest way to put it is the hypo is considered a co dominant trait or a visual het. Super hypos are considered dominant or the " homozygous " hypo.
It works somewhat like hets and visuals.
Hypo x Normal = 50% hypo , 50% normal ( all hets are visual hypos )
Super Hypo x Normal = 100% Hypo

Some folks theorize that at least 1 line of T+ albino boas are actually recessive hypos.
Ghost are a visual combination of co dom ( hypo ) and Anery ( recessive ) that gives it the faded look since both traits work against each other.

Alas tho , hypo sibs are nothing more than normals het for nothing.

Hypomelanistic - a snake having less black and/or brown color than a wild-type.

Seeing as this has been brought to some peoples attention, and I am sorta guilty (not really) of selling " Hypo Siblings" Or Nice normals as some would say, I think that if the definition of Hypo as stated in this quote is true then, how do people decide which is really a "Hypo" ? Alot of times people have crappy cameras, all their pics make the snakes look orange or make the reds look brown or black, So yes it does irritate me that when you buy these from a "Known Breeder", Who bred these and half were normal looking and the others look like the parent a HYPO, and try to sell them as such, you get,oh they are nothing more then "Nice Normals" And I know its been a long while since I've been to school or read a dictionary, But doesn't Sibling mean brother & sister or Children of the parents ????

Originally Posted by BryonsBoas

The simplest way to put it is the hypo is considered a co dominant trait or a visual het. Super hypos are considered dominant or the " homozygous " hypo.
It works somewhat like hets and visuals.
Hypo x Normal = 50% hypo , 50% normal ( all hets are visual hypos )
Super Hypo x Normal = 100% Hypo

Some folks theorize that at least 1 line of T+ albino boas are actually recessive hypos.
Ghost are a visual combination of co dom ( hypo ) and Anery ( recessive ) that gives it the faded look since both traits work against each other.

Alas tho , hypo sibs are nothing more than normals het for nothing.

Bryon,
Here is a very interesting article written by Paul Hollander describing Hypo as a Dominant, rather then Co-Dominant trait:

Salmon: Is it a dominant or codominant mutant gene?

by Paul Hollander
(Freely distributable for noncommercial purposes.)

I have only seen a couple of salmons in the flesh and have not bred salmons or any other boa constrictors. The conclusions reached here are based on data from the Journal of Heredity paper at www.salmonboa.com and what has been reported in forums like the boa forum at www.kingsnake.com.

For simplicity, each mutant or abnormal gene is classified as one of three types. These three types are dominant, recessive, and codominant mutants. Each mutant gene is dominant, recessive, or codominant to the wild type or normal version of the gene.

Part of the answer to the classification of the salmon mutant lies in the definitions used. Some standard genetics definitions are located at the end of this file. Unfortunately, many herper genetics web sites do not use standard genetics definitions.

Two salmon boas can produce a normal baby. This is only possible if both parents are heterozygous. In this case, both snakes have a pair of genes made up of a salmon mutant gene and a normal gene. By definition, a mutant gene is recessive if the heterozygous creature looks normal. As a heterozygous salmon boa does not look normal, salmon cannot be a recessive mutant gene.

Therefore, salmon must be either a dominant mutant gene or a codominant mutant gene. Which is it?

In the Journal of Heredity paper, there was one predicted homozygous salmon x normal mating. All the babies were heterozygous salmons, as expected, which indicated that the salmon boa did have a pair of salmon mutant genes. There was also one heterozygous salmon x predicted homozygous salmon mating. All the babies were either homozygous salmons or heterozygous salmons, again as predicted. This indicated that the heterozygous salmon boas can be separated from the homozygous salmons.

Ideally, a codominant mutant should always produce a heterozygous form that can be distinguished from the two homozygous forms. For what it's worth, my definition of a codominant is a little looser: An untrained person can spend five minutes looking at homozygous normal individuals, heterozygous individuals, and homozygous mutant individuals. After that, he can sort a mixture of 100 snakes into the three genotype categories with at least 95% accuracy. From the posts on the www.kingsnake.com boa forum, the breeders can't do anywhere near that well even after a lot of experience.

Some mutant genes are constant in their expression. Other genes are quite variable in expression. Different genetic backgrounds in different individuals and different environments are known to control variation in such genes. Salmon seems to be one of the mutants that shows variable expressivity.

In my opinion, when looking for homozygous salmons, the authors of the Journal of Heredity paper picked out the snakes that were most different from normal. And they did not test enough snakes that were in the range where the phenotypes of heterozygous salmon boas overlap the phenotype of homozygous salmon boas. In other words, the classification of salmon as a codominant (AKA incomplete dominant) mutant gene is an artifact of insufficient testing.

As salmon does not fit the definition of a codominant mutant gene above, it is a dominant mutant gene by elimination. However, due to its variable expressivity, the salmon mutant is not a textbook perfect example of a dominant mutant gene. "Dominant" is simply the best available fit, not an exact fit.

Definitions:

Homozygous: The two genes in a gene pair are the same. Examples include two normal genes, two albino genes, and two salmon genes.

Heterozygous: The two genes in a gene pair are different. Examples include a normal gene paired with an albino gene and a normal gene paired with a salmon gene.

Recessive mutant gene: A gene that produces a detectable, abnormal effect only when homozygous. One example is the albino mutant gene. Black pigment is not produced when there are two albino genes in the gene pair. The normal amount of black pigment is produced when there are either two normal genes or a normal gene and an albino gene in the gene pair.

In other words, a mutant gene is a recessive if a creature with a mutant gene paired with a normal gene looks like a creature with a pair of the normal genes. The three gene pairs produce two phenotypes.

Dominant mutant gene: A gene that produces the same detectable, abnormal effect when either homozygous or heterozygous. As yet, there aren't any really good examples of dominant mutants in snakes. One good example is solid black coloration in pigeons. A bird with two mutant genes is solid black instead of shades of slate gray with two black bars on each wing. A pigeon with one mutant gene paired with a normal gene is also solid black.

In other words, a mutant gene is a dominant if a creature with a mutant gene paired with a normal gene looks like a creature with a pair of the mutant genes. The three gene pairs produce two phenotypes.

Codominant mutant gene: A gene that produces one abnormal effect when homozygous and another abnormal effect when heterozygous. For example, a reticulated python that has a tiger gene paired with a normal gene looks intermediate between a python with a pair of normal genes and one with a pair of tiger genes. The three gene pairs produce appearances that are different enough that the genes can be identified from the python's appearance. Synonyms: Partial dominant, semidominant, incomplete dominant, less than dominant, transdominant, etc.

In other words, a mutant gene is a codominant if a creature with a mutant gene paired with a normal gene does not look like either a creature with a pair of the mutant genes or a creature with a pair of the normal genes. Each of the three gene pairs produces its own phenotype.

Glad I looked to see that you had addressed that, Mike, as I was about to. I am no genetics whiz, and have been learning as I go here...but it is very clear that many people latch on to terms and apply them haphazardly. Dominant and codominant traits express themselves differently...they not different forms of the same trait.