Glossary

How to use this page

These are the words that come up in this guide, in plain English. Each one links to the chapter that explains it in full.

Numbers

• 50% possible het. A normal-looking baby from a het × normal pairing. Each one has a 1 in 2 chance of carrying the hidden gene, and you can't tell which ones by looking. See Genetics.
• 66% possible het. A normal-looking baby from a het × het pairing. Each one has a 2 in 3 chance of being a het. It's a chance, not a sure thing. See Genetics.
• 100% het. A snake that is sure to carry one copy of a recessive gene, for example because one parent was a visual. See Genetics.

A

• Allelic (allelic complex). Genes that sit in the same slot in a snake's DNA. A snake can carry only two from the group, and two different ones together can make a new look. See Genetics.
• Assist-feeding. Helping a snake that won't eat on its own get a meal down. It's a last resort for a baby that keeps refusing and is losing weight. See Hatching and hatchlings.
• Atresia. When follicles stop growing and the body takes them back in. The female isn't sick; she's skipping that year. See Follicles.
• Axanthic. A recessive gene that takes away yellow color. There are separate Axanthic lines that don't mix, and in this guide Axanthic means the VPI line. See Genetics.

B

• BEL (blue-eyed leucistic). A white or near-white snake with blue eyes, made by two genes from the BEL group, such as Lesser, Butter and Mojave. Some of these snakes get bulging eyes, so we never make them. See Genes to avoid.

C

• Candling. Shining a cool light against an egg in a dark room. Blood vessels inside mean the egg is fertile. See Eggs and incubation.
• Clutch. All the eggs a female lays at one time, usually about 6 to 7. See Eggs and incubation.
• Combo. A snake with more than one morph gene. Some combos are fine, and some cause health problems. See Genes to avoid.
• Cooling. Lowering the temperature in fall to copy the dry season. It's optional, and no study shows it helps a female ovulate. See Conditioning.
• Cryptosporidium. A stomach parasite that makes a snake bring up its meals and lose weight. There's no cure, and a snake that has it shouldn't be bred. See Choosing breeders.

D

• Dent. A dip in an egg's shell. Dents in the first few weeks mean the eggs are drying out; dents in the last week or so are normal. See Eggs and incubation.
• DNA test. A lab test, usually on a piece of shed skin, that shows which genes a snake carries. It can also tell males from females. See Genetics.
• Dominant. A gene where one copy and two copies look the same. Pinstripe is the usual example. See Genetics.

E

• Egg-binding (dystocia). When a female can't lay some or all of her eggs. Call a reptile vet right away; it needs treatment within 48 to 72 hours of the first laying attempts. See Ovulation to laying.
• Egg cutting. Slitting eggs open near hatching instead of waiting for the babies to pip on their own. Breeders disagree about it, and there's no study either way. See Hatching and hatchlings.
• Egg tooth. A tiny tooth on a baby's snout that it uses to slit the shell. It falls off within a week or two. See Hatching and hatchlings.
• Euthanasia (humane). Ending an animal's life without pain. For a snake, this is always a vet's job. See Hatching and hatchlings.

F

• Follicle. An egg starting to grow in the female's ovary. Follicles are measured in millimeters to time breeding. See Follicles.
• Follicular stasis. Follicles that stay large and neither ovulate nor shrink. A female with this needs a vet. See Follicles.

G

• Gene. A small piece of a snake's DNA. Every snake has two copies of each gene, one from each parent. See Genetics.
• Gravid. Carrying eggs. A gravid female usually won't eat until she lays. See Ovulation to laying.

H

• Het (heterozygous). A snake with one hidden copy of a recessive gene. It looks normal but can pass the gene to its babies. See Genetics.

I

• Inclusion body disease (IBD). A virus that spreads through body fluids, mating, bites and mites. In pythons it causes severe nerve problems, and it can't be cured. See Choosing breeders.
• Incomplete dominant. A gene where one copy shows, and two copies make a stronger look called the super form. Pastel is an example. See Genetics.
• Incubator. A box that keeps eggs at a steady temperature until they hatch, about 2 months. See Eggs and incubation.
• Introduction. Putting the male into the female's enclosure so they can breed. See Introductions and locks.

K

• Kink. A crooked bend in the spine. Some genes are linked to kinks. See Genes to avoid.

L

• Laying box. A private hide or tub with an entrance hole, lined with slightly damp moss, where the female can lay. See Ovulation to laying.
• Line. One version of a gene. Some lines look the same but are different changes that don't mix, like Axanthic. See Genetics.
• Lock. When the male and female join tails to mate. It can last up to about a day, and you should never pull them apart. See Introductions and locks.

M

• Morph. A snake with a visible gene change that alters its color or pattern. See Genetics.

N

• Nidovirus (serpentovirus). A virus that causes breathing problems, though many snakes show no signs. There's no treatment, and it's tested with a mouth swab. See Choosing breeders.

O

• Ovulation. When the female releases her eggs from her ovaries. It shows as a swelling in the middle to lower third of her body that lasts about a day. See Ovulation to laying.

P

• Palpation. Gently feeling the lower belly by hand to find follicles. It's a rough check, not a timer. See Follicles.
• Pip (pipping). When a baby slits its shell and pokes its nose out. Most stay inside the egg for another 24 to 48 hours. See Hatching and hatchlings.
• Popping. A way to tell a baby's sex by gently rolling a thumb up the underside of its tail. It can hurt the snake, so leave it to an experienced breeder or a vet. See Hatching and hatchlings.
• Possible het. A snake that might carry a recessive gene. See 50% possible het and 66% possible het at the top of this page. See Genetics.
• Power-feeding. Big meals to push a snake up to weight fast. It makes egg-binding more likely. See Conditioning.
• Pre-lay shed. The shed a female has about 2 to 3 weeks after ovulation. Eggs usually come about 30 days after it. See Ovulation to laying.
• Probing. A way to tell a snake's sex with a blunt probe slid into the tail. Males probe deeper. Leave it to an experienced breeder or a vet. See Hatching and hatchlings.
• Proven. A female that has laid a good clutch, or a male that has fathered one. A "proven het" is a het confirmed by a DNA test or by its own babies. See Choosing breeders.
• Punnett square. A simple grid that shows the possible babies from two parents. The cross table in the Genetics chapter works the same way. See Genetics.

Q

• Quarantine. Keeping a new snake away from your others while you watch it and test it. We do at least 60 days, and some vets advise longer. See Choosing breeders.

R

• Recessive. A gene that only shows when a snake has two copies. Clown, Piebald and Albino are examples. See Genetics.
• RGI. Short for Rare Genetics Inc., the lab named in this guide that tests shed skin for genes. See DNA test. See Genetics.

S

• Sex-linked. A gene carried on the sex chromosomes, so how it's passed on depends on whether the parent is male or female. Banana (Coral Glow) works this way. See Genetics.
• Slug. An egg that isn't fertile. Slugs are smaller and yellowish. See Eggs and incubation.
• Spider group. A group of genes in the same slot, including Spider, Champagne, Woma and Spotnose, linked to the wobble. We keep all of them out. See Genes to avoid.
• Spurs. Two small claws beside a snake's vent. Males use them to stimulate the female while courting. See Introductions and locks.
• Substrate. The damp material the eggs sit in, such as vermiculite or perlite mixed with water. See Eggs and incubation.
• Super form. The two-copy form of an incomplete dominant gene, such as Super Pastel. See Genetics.

T

• Test breeding. Breeding a possible het to a visual to find out if it carries the gene. One visual baby proves it. See Genetics.

U

• Ultrasound. A machine that uses sound waves to see inside the snake. Breeders use it to measure follicles. See Follicles.

V

• Vent. The opening on the underside of a snake, where the tail starts. See Introductions and locks.
• Visual. A snake that shows a gene. For a recessive gene, that means it has two copies. See Genetics.

W

• Wobble. A head that tilts, corkscrews or misses when striking, seen in the Spider group. See Genes to avoid.

Y

• Yolk. The food store in the egg. The baby finishes it before crawling out, so don't pull a baby out early. See Hatching and hatchlings.