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I got a Leucistic Rat Snake the other day. When I got it, I thought all leucistic rats were Texas rats, but now I realize that it could be either a Texas rat or a black rat. Is there a say to tell which it is?

I have several kings, milks and corns, but the rats are new to me.

Thanks in advance.

can you post a pic?

There is no clearcut way to tell a Texas Ratsnake from a Black Ratsnake, as scalecounts largely overlap. Texas Rats generally are smaller and more slender than Black Rats, but there are many many exceptions to this rule. Also Texas Rats can sometimes be quite black, and Black rats can sometimes have a well defined pattern. So without locality data, you can propably tell a very typical Black Rat from a very typical Texas Rat by their colour, but even then you'll have to keep your fingers crossed. There is absolutely no way to tell a leucistic Texas Rat from a leucistic Black Rat.

Therefore...As common as leucistic texas rats are, and given the debate over whether some (most?? ALL??) leucistic black rats may have texas rat influence, in all liklihood you have a luecistic texas rat. Either way, you have a great snake. ENjoy!

If there is absolutely no way to tell them apart, doesn't that make them the same snake (whether it's leucistic or not)?
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2.0 Pantherophis obsoletus obsoletus
0.2 Pantherophis guttatus guttatus

No.... If you have a juvenile yellow rat and a juvenile everglades rat side by side and can't tell the difference does that make them the same thing?
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0.1 Snow Corn "Hope"
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
0.0.1 MO Locale Black Ratsnake "Molly" (Flogging Molly)

As we say in Missouri, "I ain't goin back to Missouri!"

There is one way to tell them apart, but since it involves mtDNA analysis by an expert that would cost you a fortune, you might as well go with the there is no way to tell answer. (Burbrink, F.T., R. Lawson & J.B. Slowinski. 2000. Mitochondrial DNA phylogeography of the North American rat snake (Elaphe obsoleta): a critique of the subspecies concept. Evolution, 54: 2107-2114.)

The real answer is that since we use color and pattern to tell these snakes apart, and since your snake has no coloring or pattern, it makes no difference unless you want to breed your snake to a wild type. If you have a male, and you breed it to a wild type Texas Rat and a wild type Black Rat, one of the clutches should produce nothing but wild types and the other should produce intergrades.

I think the best thing to do is to tell yourself you have a nice white Rat Snake, and then relax about it and enjoy your animal. There is no such thing as a bad looking Elaphe obsoleta.

n/p

Well, an Everglades and a yellow would eventually distinguish themselves by their adult coloration. Mr. Bronsgeest said there was absolutely no way to tell the two of them (Texas and black) apart. Someone else said that there was a way -- through mitochondrial DNA, which is true as far as I know. But, if there was "absolutely" no way to tell them apart, that means they would be the same snake. I just brought it up because there are those people (I don't know their names) who are trying to get all the pantherophis in the east all lumped together into one species, and I think it's an interesting conversation.
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2.0 Pantherophis obsoletus obsoletus
0.2 Pantherophis guttatus guttatus

If you look at the reference that I posted in this thread, you can read the research for yourself. (Burbrink, F.T., R. Lawson & J.B. Slowinski. 2000. Mitochondrial DNA phylogeography of the North American rat snake (Elaphe obsoleta): a critique of the subspecies concept. Evolution, 54: 2107-2114.) I was able to find a site in England where you could read it for free (in PDF format).

Burbrink, Lawson and Slowinski did some great research and published their results. Their evidence and arguement, TBMK, has not yet won the day in the scientific community but the paper is worth reading.

Once again, the only way to tell at this time would be to cross the snake with a wild type and see if you get standard offspring or intergrades. If you don't plan to breed your snake, why not just tell your friends that you have a white American Rat Snake because we know for shure that this is correct.

Based on an analysis on geographical variation in mitochondrial DNA of Elaphe obsoleta, Burbrink et al divided this species into 3 different lineages. The Black Ratsnake's (as in Elaphe obsoleta obsoleta) distribution however, covers the northern half of the areas of all of these 3 new species. So you have Black Ratsnakes in Elaphe alleghaniensis (Eastern ratsnake), in Elaphe spiloides (Midland ratsnake) and in Elaphe obsoleta (Western Ratsnake). In this classification Texas Ratsnakes are assigned to Elaphe obsoleta. So if you compare mitchondrial DNA of a Texas Rat with that of a Black Rat from the western part of it's range, you propably will not find much difference. Therefore it's not a very usefull method to test the 'purity' of your leucistic ratsnakes. And yes, it would be rather expensive too.

It was my understanding that the leucistic Black Rat that was found was from the "spiloides" part of the country so the test would work. I wonder what Dr. Burbrick would charge for the test? (LOL)

Wow! LOL, I didn't mean to open a can of worms.

Anyway, even if I can't find out which she is, here's a picture of her:

In the picture it looks like it has the bug eyed trait. This is common in lucy Texas rats but not in pure lucy black rats.

Thank you!

Are you shure of that? Did thid info come from the breeder who started the line?