History of the Tessera Mutation

Beyond their striking appearance, the primary value of the Tessera Corn Snake lies in its mode of inheritance. Unlike many popular morphs that are recessive, the Tessera gene is dominant.

This genetic dominance offers a distinct advantage for breeders:

• Immediate Results: You do not need to wait for the second generation (F2) to see visual results.
• High Yields: Breeding a visual Tessera to any non-Tessera corn snake will produce approximately 50% visual Tessera mutants in the very first clutch.
• Homozygous Power: If you breed a Tessera Homozygote (Super Tessera) to a non-Tessera, you will produce 100% visual Tessera offspring.

Note on Genotypes: Homozygote Tesseras are exceedingly rare in the hobby. Currently, there are no visual markers to distinguish a Homozygote from a Visual-het. Therefore, most Tesseras cited or advertised for sale are likely Visual-hets.

The Origin of the Tessera Corn Snake

2007: The Acquisition

• The Order: Graham Criglow asked KJ Lodrigue to purchase a 1.2 trio (one male, two females) of Striped Motleys on his behalf, as he was unable to receive the shipment personally.
• The Mix-up: Upon arrival, KJ discovered a mistake: the shipment was actually a 2.1 reverse trio (two males, one female).
• The Gift: KJ and Kasi recommended that Graham gift the extra male to me. Graham agreed, a gesture for which I am profoundly grateful.

2008: The Breeding Trials Both the Lodrigues and I independently bred our males to unrelated (novel) corn snakes. The results were drastically different:

• The Lodrigues: In the middle of a stressful move to another state, they had limited success, producing only four non-mutant, Okeetee-looking corn snakes.
• My Results: I produced over 50 fertile eggs, resulting in about 24 "Tesseras" (a name chosen by the Lodrigues to describe the tessellated lateral markings).

The Genetic Discovery I paired my male Tessera with three different female corn snakes to test the genetics:

1. One Okeetee-ish female (Het for Stripe and Amel).
2. Two F1 Locality Okeetees (Chip Bridges Rhett Butler Line).

The Outcome I initially expected to see Striped Motleys. However, I was surprised to see the same "flawless" pattern appear in offspring from all three females.

• The Realization: If the trait were recessive (like Striped Motley), it should not have appeared when bred to the wild-type Okeetees.
• The Conclusion: Since the pattern appeared consistently across all clutches—including those from wild-type mothers—it was obvious that we had discovered a new dominant mutation.

The Phenotypic Mystery

Upon receiving the trio in 2007, the group immediately noticed something peculiar. The snakes did not match their description:

• The Advertisement: They were sold as "Striped Okeetees" (implying a mix of Striped and Okeetee genetics).
• The Appearance: They looked like nearly flawless Striped Motleys.
• The Anomaly: The dorsal (back) stripes were nearly contiguous from neck to tail tip. This pattern perfection had never been seen in any corn snake pattern mutant before.

The Genetic Conflict

The physical appearance of the snakes made the claimed parentage biologically impossible.

• The Claim: The seller stated the parents were a Striped Corn x Okeetee Corn.
• The Problem: Offspring from a recessive Striped mutant bred to a wild-type Okeetee should not look like Motleys. They should appear normal (wild-type) carrying the recessive gene, unless the Okeetee also carried recessive traits.
• Deductions on Lineage

Because the original breeder is out of the hobby and unreachable, it is unclear if these snakes were F1 (first generation) or F2 (second generation). However, the author deduced the following theories to explain the "Tessera" gene origin:

Theory A: If the snakes were F1 (First Generation) If these snakes were the direct result of the stated pairing, the "Striped" parent used was likely not just Striped, but Striped AND Tessera.

Theory B: If the snakes were F2 (Second Generation) Even if these were second-generation offspring, the "patriarch" (male ancestor) of the line was likely a Striped Tessera.

Theory C: The "Name" Clue Since the seller specifically called them "Striped Okeetees," it is highly probable that the parents were actually a Classic Tessera and an Okeetee—rather than a recessive Striped mutant and an Okeetee.

 

Early Observations & Genetic Anomalies

The Unknown Potential In the early stages of working with the Tessera line, the full range of physical variations (phenotypes) this gene could produce was still a mystery.

The "Sibling Effect" A unique genetic feature emerged that is atypical for most corn snake mutations:

• Enhanced Non-Mutants: The siblings that did not inherit the Tessera gene often appeared superior to average corn snakes.
• The Look: These non-mutant siblings displayed enhanced patterns, brighter colors, and cleaner markings.

Absence of Hybrid Markers Despite the unique look of the Tesseras, there is no evidence to suggest they are hybrids (a cross between two different species).

• Pure Corn Snake Traits: The enhancements seen in the siblings are strictly improvements on existing corn snake features.
• Conclusion: Because the traits are simply "better" versions of standard corn snake colors and patterns—rather than foreign traits—it supports the theory that Tessera is a mutation within the species, not a result of hybridization.

 

The Early "Resume" of the Tessera

When the mutation was first discovered, its full potential was still unknown. However, the author noted a few key observations:

• The Sibling "Glow-Up": Usually, a mutation only affects the snakes that actually inherit the gene. In this case, even the non-Tessera siblings (those without the mutation) looked better than average. They showed:

  • Cleaner, brighter colors.

  • More consistent and "enhanced" patterns.

• No "Hybrid" Concerns: In the reptile hobby, people often worry that a radical new look comes from breeding two different species together (hybridization).
• Purebred Evidence: The author found no "hybrid markers." Because the siblings just looked like "better versions" of standard corn snakes—rather than looking like a different species entirely—they concluded the Tessera is a natural corn snake mutation.
• Summary of the Discovery

Feature	Observation
Genetics	Confirmed to be Dominant (not recessive like most patterns).
Visuals	Contiguous dorsal stripes from head to tail.
Siblings	Even the "normal" babies showed improved color and clarity.
Species	Believed to be a pure Corn Snake mutation, not a hybrid.

 

1. The Dorsal Stripe: Consistency and Breaks

The most defining feature of a Tessera is its contiguous dorsal stripe (a solid line running down the back).

• Continuous Pattern: Unlike the "Striped" or "Motley" mutations—where a break in the stripe usually means the end of the line—a Tessera's stripe will almost always resume immediately after any interruption.
• The "Girdle" Exception: Many Tesseras have a break near the "girdle" (the area above the cloaca/tail base). However, unlike other mutants, the Tessera's stripe typically continues all the way to the tip of the tail after this break.

Statistical Breakdown of Stripe Quality:

• 50%+: Have a perfect, unbroken stripe from head to tail.
• 25%: Have minor interruptions (2 to 4 breaks).
• 25%: Have significant interruptions (5 to 20+ breaks).
• Bloodred Crosses: Breeding a Tessera to a "Bloodred" type can result in a stripe that is more than 50% broken.

2. Breeding for Pattern

Interestingly, a Tessera does not need a perfect stripe to produce perfect-striped offspring.

• The original three snakes that started this line actually had broken stripes.
• Despite this, they produced many children and grandchildren with perfectly complete stripes.

3. Pigmentation: The "Black" Factor

The Tessera mutation handles black pigment (melanin) very differently than the older Striped and Motley mutations.

• High Black Pigment: Over 2/3 of Tesseras produced show a large amount of black in their pattern. For comparison, only about 1% of standard Striped or Motley corn snakes show this much black.
• Low Black Pigment: Less than 1/4 of Tesseras have little to no black; these are usually "Striped Tesseras" (snakes carrying both the Tessera gene and the recessive Striped gene).

1. Ventral (Belly) Patterns

Unlike the dorsal stripe, which is fairly consistent, Tessera belly patterns are highly variable.

• Wild-Type Look: A very small number of Tesseras have the full "checkered" belly seen in normal corn snakes.
• Reduced Checkering: About 1/3 of the population has minimal checkering (only 15% to 30% of the usual amount).
• Clear Bellies: About 1/3 or more have no checkering at all.
• The "Ventral Keel" Look: Interestingly, some snakes with clear bellies still have twin rows of black markings running down the outer edges of their stomach scales.

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2. A Revolution in Corn Snake Breeding

The Tessera mutation has "grafted a new branch" onto the corn snake family tree because it allows for pattern combinations that were previously impossible.

The Black Pigment Problem

Historically, if a breeder wanted a Striped or Motley snake, they had to accept a massive reduction in black pigment. Those recessive genes naturally "wash out" black or white markings.

The Tessera Solution

Because Tessera is a different kind of mutation, it allows breeders to create striped patterns without losing the dark pigments. This opens the door for:

• High-Contrast Albinos: Keeping crisp white borders.
• Darker Striped Variations: Infusing the Tessera gene into existing color morphs (like Amel, Anery, or Ghost).
• Complex Hybrids: Combining Tessera with the Motley or Striped genes to create entirely new "designer" patterns.

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Summary Table: Tessera vs. Traditional Striped/Motley

Feature	Traditional Striped/Motley	Tessera Mutation
Black Pigment	Usually reduced or absent	Often retained/enhanced
Stripe Continuity	Breaks often end the stripe	Stripe usually resumes after breaks
Gene Type	Recessive (needs two copies)	Dominant (needs only one copy)
Belly Pattern	Typically clear/white	Highly variable (clear to checkered)