Reptile & Amphibian Forums

Hi Guys
I know this must be a very dumb question to ask, but I'm new in keeping snakes. What does T positive and T negative mean? What is the different in the color variation they show? I've seen some photos, but just can't figure it out what I should be looking for.
Thanks for any answers.

Benny.

T and T- (T plus and T minus) stand for Tyrosinase positive and negative.

Tyrosinase is an enzyme necessary in the pathway to produce melanin from tyrosine. This enzyme is the missing ingredient in many (most) amelanistic herps. Those animals can be regarded as tyrosinase negative albinos, but we just normally call them albinos or amelanistic.

There is a rarer form of amelanism where the animal does produce the enzyme tyrosinase, but still doesn't produce normal melanin because there is something else missing from the pathway. This is referred to as tyrosinase positive albinism.

T albinos usually look different than T- (normal) albinos. It has been demonstrated in a number of herp lines.

Unfortunately, this has led to a rash of people finding an animal that doesn't look quite like "normal" albinos and labeling it T without any evidence that the animal actually produces tyrosinase or not.
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Chris Harrison
San Antonio, Texas

Thank you, Chris, for explaning this in detail.

Benny