Corn Snake Morph Calculator

Corn Snake Morph Calculator

Estimate the genetic outcomes of a breeding pair. This calculator focuses on the simple recessive Amelanistic (Amel) trait.

function calculateMorphs() { var parent1 = document.getElementById("parent1").value; var parent2 = document.getElementById("parent2").value; var resultDiv = document.getElementById("result"); var resultText = '

Expected Offspring Percentages:

'; // Normalize the pairing so order doesn't matter if (parent1 > parent2) { var temp = parent1; parent1 = parent2; parent2 = temp; } // Pairing: Normal (AA) x Normal (AA) if (parent1 === "AA" && parent2 === "AA") { resultText += '
• 100% Normal
'; } // Pairing: Normal (AA) x Het Amel (Aa) else if (parent1 === "AA" && parent2 === "Aa") { resultText += '
• 50% Normal
'; resultText += '
• 50% Normal (Het for Amelanism)
'; } // Pairing: Normal (AA) x Amel (aa) else if (parent1 === "AA" && parent2 === "aa") { resultText += '
• 100% Normal (Het for Amelanism)
'; } // Pairing: Het Amel (Aa) x Het Amel (Aa) else if (parent1 === "Aa" && parent2 === "Aa") { resultText += '
• 25% Normal
'; resultText += '
• 50% Normal (Het for Amelanism)
'; resultText += '
• 25% Amelanistic (Visual Amel)
'; } // Pairing: Het Amel (Aa) x Amel (aa) else if (parent1 === "Aa" && parent2 === "aa") { resultText += '
• 50% Normal (Het for Amelanism)
'; resultText += '
• 50% Amelanistic (Visual Amel)
'; } // Pairing: Amel (aa) x Amel (aa) else if (parent1 === "aa" && parent2 === "aa") { resultText += '
• 100% Amelanistic (Visual Amel)
'; } resultText += '

Note: These are statistical probabilities per egg, not a guarantee of the exact ratio in any single clutch.'; resultDiv.innerHTML = resultText; }

Understanding Corn Snake Genetics

Planning a breeding project for corn snakes requires a basic understanding of genetics. Many of the beautiful color and pattern variations, known as "morphs," are the result of simple genetic traits. This calculator helps you predict the outcomes of pairing snakes with different genetic makeups for the Amelanistic trait.

Key Genetic Terms

• Gene: A unit of heredity that determines a specific trait. For example, the gene for red pigment.
• Allele: A variant form of a gene. In our example, there's an allele for producing red pigment (Normal) and an allele for not producing it (Amelanistic).
• Dominant: An allele that expresses its trait even when only one copy is present. The Normal allele is dominant.
• Recessive: An allele that only expresses its trait when two copies are present. The Amelanistic allele is recessive.
• Homozygous: Having two identical alleles for a trait (e.g., two Normal alleles or two Amel alleles).
• Heterozygous (Het): Having two different alleles for a trait (e.g., one Normal and one Amel allele). A snake that is "Het for Amel" looks normal but carries the recessive Amel gene.
• Phenotype: The observable, physical appearance of the snake (e.g., a "Normal" or "Amelanistic" looking snake).
• Genotype: The actual genetic makeup of the snake (e.g., Homozygous Normal, Heterozygous, or Homozygous Recessive).

Example Calculation Walkthrough

Let's see what happens when you breed a Het Amel snake to a visual Amelanistic snake.

1. Parent 1 (Het Amel): This snake looks normal but carries the recessive gene. Its genotype is Aa (one dominant Normal allele 'A', one recessive Amel allele 'a').
2. Parent 2 (Amelanistic): This snake is visually Amel. Its genotype must be aa (two recessive Amel alleles).
3. The Calculation: Each parent contributes one allele to each offspring. We can map the possibilities using a Punnett Square.
   • If Parent 1 gives 'A' and Parent 2 gives 'a', the offspring is Aa (Het Amel).
   • If Parent 1 gives 'a' and Parent 2 gives 'a', the offspring is aa (Amelanistic).
4. The Result: Statistically, you can expect 50% of the offspring to be Het Amel (looking normal but carrying the gene) and 50% to be visual Amelanistics. You can verify this by selecting "Het Amel" and "Amelanistic" in the calculator above.

Beyond a Single Trait

While this calculator focuses on the simple recessive Amelanistic trait, corn snake genetics can be much more complex. Many popular morphs, like the Snow (Amelanistic + Anerythristic) or Blizzard (Amelanistic + Charcoal), are "combo morphs" that involve combining two or more separate recessive traits. There are also co-dominant and dominant traits, each with their own rules of inheritance. This tool provides a solid foundation for understanding the fundamental principles at play in any corn snake breeding project.