What's subspecies?

[Snakesitter]

Hi there.

I'm looking after a snake for a friend. Now I know he's a marcianus, but how do I know which marcianus he is?

Wikipedia says there's three subspecies of marcianus: marcianus, praeocularis and bovalli. I've not been able to find any information or pictures on what the differences are. Perhaps somebody here can help.

Thanks

Karl

[ssssnakeluvr]

preoculis and bovalli are mexican subspecies and not available in the pet trade. He have a marcianus marcianus, the common checkered garter, nice snakes too!!!

[GarterGuy]

Yep, pretty much the only ones out there are T.m.marcianus.

[Snakesitter]

Cool enough. Does anybody know what the differences are between the three?

[Thamnophis]

The two other subspecies are not Mexican, but live even more southwards...

Thamnophis marcianus bovalli - from southwest Nicaragua up to northern Costa Rica.
Thamnophis marcianus marcianus - from southwest Kansas to the west up to southeastern California and southwards, viavia the north and east of Mexico, up to northern-Veracruz. In Tehuantepec (Oaxaca, Mexico) lives an isolated population.
Thamnophis marcianus praeocularis - from the Yucatan-peninsula, via Belize and northeastern Guatemala up to western Honduras.

I do not know the physical differences.