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In corn snakes, there is a recessively inherited neurological condition called "Star Gazing". This page is dedicated to the education of the corn hobbyist and breeder about this condition. Below are some frequently asked questions about Star Gazing in corns answered with what we presently know about this condition.

Is Star Gazing recognizable at hatch?

Yes, absolutely. Although at rest it is difficult to detect, if you simply get the hatchling crawling about, the signs are easy to spot.

What signs do Star Gazers show?

At rest, a Star Gazer may appear just as normal as any other hatchling. When stimulated to move about, they seem to have difficulty with balance, swinging their heads to and fro as they slither. If agitated, they get more animated and swing their heads faster, more wildly, and may even flip their heads over in a loop. As the name implies, Star Gazers may throw their heads back and appear to gaze towards the stars at times. They may lay in odd positions with their heads upside down. Sometimes they will get themselves flipped over and slither along on their backs for a time before righting themselves. The more intensely focused on something they are, the more difficulty they have (such as when they're excited about eating, they may miss a strike or swing their heads wildly.)

Mentally, these snakes are normal. They respond just as any hatchling would with excitement at feeding, gripping of your hand as they crawl on you, and curiosity and exploring while "tongue sniffing". They can eat normally (albeit sometimes upside down or in a weird position), they can shed normally. They don't appear to suffer any pain or discomfort and are perfectly content to go about their daily duties, even if a bit wobbly.

Clinically, the condition is very similar to an animal that is bilaterally vestibular (meaning an animal that doesn't have balance sensation from either side of its inner ear). Click here to view some video clips of Star Gazing hatchlings:

Star Gazers out actively exploring their nest box

Star Gazers excited after being moved into a deli cup



What causes Star Gazing?

At present, it is believed that Star Gazing is not an infectious disorder, but rather an inheritable one. Snakes are born with the affliction and do not develop it over time or with exposure to Star Gazers. Star Gazing appears to be the result of a simple recessive gene. The gene must be inherited from both parents for a hatchling to be affected. The gene does not appear to be sex-linked (both males and females are affected equally) and does not appear to be linked to the Sunkissed gene that it originated with (both Sunkisseds and non-Sunkisseds are affected equally).

The anatomical cause of the disorder at present is unknown, but research is underway to determine the result of the gene on brain structure to see if we can identify the area of the brain that is affected and how it's affected.

What does "S-Factored" and "*S" mean?

Since Star Gazing is believed to be a simple recessive gene, we refer to the gene as the S-factor or *S for short. A snake that is said to be S-factored is a snake that carries one copy of the Star Gazing gene. A snake that is possible S-factored means that there is reason to believe the snake may be carrying the gene, but it is not 100% certain. Some things to remember about inheritance of a recessive gene:

  • If one parent is known to be S-factored, the hatchlings would then be known to be 50% possible S-factored.
  • If both parents are known to carry *S or if a Star Gazer is produced in the clutch with a hatchling, that normal-appearing hatchling is known to be 67% possible S-factored.
    (1/4 of the clutch should be Gazers, 1/2 should be S-factored, and 1/4 should be clear of the gene. Since you can't tell *S clear hatchlings from S-factored hatchlings, until they are tested they are 67% possible S-factored.)

Which corns are at the highest risk for carrying Star Gazing?

While Star Gazing has not been proven to be linked to any particular morph, it is seen most often in Sunkisseds and Sunkissed descendants simply because the gene popped up in the original line of Sunkisseds. Since the gene can be passed on regardless of the morph, any snake descended from these original carriers is possible S-factored. Unfortunately, with the way family histories are lost and information lost in transactions, it is not possible to guarantee any corn is not a carrier without either test crossing or having a full, accurate family pedigree showing no relation to Star Gazing carriers.

I have Sunkissed descendants in my collection, how do I test them for *S?

At present, there are two ways to positively identify carriers. The first is to have a clutch hatch out from unknown parents with Star Gazers evident in the clutch. This would then identify both parents as S-factored. The second way is to cross an unknown snake to a known S-factored animal (one that has produced Star Gazers). If no gazers are produced in a large set of eggs, you can be reasonably sure the test cross animal is clear of Star Gazing. As a general guideline, to be 95% certain the tester is clear, you need 11 healthy hatchlings with no Star Gazers. To be 99% certain, you need to produce 16.

I've bred my pair of Sunkisseds several times and never had a Star Gazer in the clutches, this means they're clear, right?

Wrong. If only one of the Sunkisseds is S-factored, you'll never see a Star Gazer in the first generation, but all of those babies would be 50% possible S-factored. Even in the second generation from this pairing, you only have a 25% chance of pairing up two S-Factored hatchlings to see Star Gazers. You have a 50% chance of pairing up a non-carrier with an S-factored animal and only a 25% chance of pairing 2 clean individuals. You can see how Star Gazing can "skip" multi generations only to pop up down the line. This is especially troublesome when the first generation is an outcross and some of normal babies get wholesaled. The gene is then silently spread into the general gene pool.

This information is freely distributable courtesy of CCCorns.com and may be printed and used as a handout.

 

Both Jeff and I are involving ourselves with this project.  We want to thank Dr. Connie Hurley, D.V.M. for the opportunity to be involved in proving out Stargazers here in Canada.
 
Here are some excellent links to follow if you would like more information on this particular defective gene and the work that is being done.  Together with other Canadian and American breeders, we hope to eventually produce clean Sunkissed lines, so that all Sunkissed projects in the future can be assured of success.

Discussion - Our Sunkissed Genes

Dr. Connie Hurley's Work

T and J Corns Stargazer Discussion

As more information becomes available we will keep you up to date, not only on results, but also on statistics.  A united effort by cornbreeders around the world is necessary to control the further spread of this defective gene.
 
HanneysCorns is proud to be involved with this worthwhile project.  We strongly caution all perspective 'Sunkissed morph' buyers to question the seller/breeder as to whether they are actively involved or have knowledge of this project.
 
Education and clean gene pools should be and is the committment we need to focus on for the future of this beautiful morph.

In early July, we will be travelling to Wisconsin to bring back 2.3 possible het Stargazers courtesy of Dr. Hurley.  These 'test' corns will be matured here and eventually bred to produce, hopefully, known hets for the 'S Factor' (what we are now labelling this recessive gene).  These known hets can then be used to test not only our foundation stock but also other Sunkissed genes here in Canada.  These known hets will not be sold; their sole purpose is as 'testing stock' for us and other Canadian breeders.
 
If you presently hold Sunkissed or Sunkissed hets in your collection and wish further information on testing your own corns, please feel free to contact us.  We will gladly help in any way we can.