Reptile & Amphibian Forums

Can someone tell me the differences between
the Black Ratsnake (E. o. obsoleta ), Eastern Ratsnake (Elaphe obsoleta), and the Midland Ratsnake (Elaphe spiloides)
I saw them all on resource sites and am wondering if they are all just Black ratsnakes (Elephe Obsoleta Obsoleta)or if they are actual ssp. Thanks for your help.
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0.1 Snow Corn "Hope"
1.0 Ball Python "Wilson" (Castaway)
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
0.0.1 Mexican Black Kingsnake "Onyx"

Elaphe obsoleta or Eastern Rat Snake is the general name that includes all five of the subspecies that make up the species obsoleta.
Elaphe spiloides is really Elaphe obsoleta spiloides, the Gray Rat Snake. (FYI: You don't capitalize the name of the species or subspecies)

I ahven't read the paper for a few years but this is essentially an outgrowth of a paper done by Burbink et al. The paper states that the obsoleta complex essentially has 3 gene pools that are roughly defined by geographic areas. All of the currently accepted ssp are included in those gene pools. Consequently, he proposes renaming the subspecies according to the geographic dividers that help define that gene pool instead of the current scheme. The first one is roughly defined by the area east of the Alleghenies. He proposes calling those Eastern Rat Snakes. The second group is defined approximately by the area between the Allegheny Mountains and the Mississippi. He proposes calling those Midland Rat Snakes. As you have surmised by now, the remaining group is then called??? (oops, I forgot the name for that group.) I may not be remembering the paper perfectly but I know I am close. Some of our more academically-minded gang will help fill in the rest of the details.

That was a wonderfull answer and very informative. But that was not exactly what I was looking for. Let me rephrase my question. Are the only ratsnakes located on the eastern half of the U.S. the following? Black, Yellow, Everglades, Grey, Emoryi, and Cornsnake (Red Rat)?
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0.1 Snow Corn "Hope"
1.0 Ball Python "Wilson" (Castaway)
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
0.0.1 Mexican Black Kingsnake "Onyx"

You forgot the foxsnakes (vulpina and gloydi)

I also forgot Kisatchie (Pantherophis slowinskii ) But what I was aiming at is to make sure that there is only one Black ratsnake and that the "Western" rat and the "Midland" rat are just common names for the black rat.
-----
0.1 Snow Corn "Hope"
1.0 Ball Python "Wilson" (Castaway)
1. Orange Albino Black Ratsnake "Chunk" (Goonies)
.1 Orange Albino Black Ratsnake "Peaches"
0.0.1 Mexican Black Kingsnake "Onyx"

then there are three different species that each include black color variants that we call black ratsnakes. If you don't agree with him then there's a subspecies of the one american ratsnake species (based on color) that we call the black rat.