Hi,
Thanks,
As far as I know they aren’t related to the Daboia russelli except that they both Viperidae.
You can look at their classification at.
http://www.kingsnake.com/viperidae/
Regarding their venom, it is quite bad, (but not as bad as the russelli).
You can learn more about its toxicity from Bryan Grieg Fry's site (look at the LD50 tables).
http://www.kingsnake.com/toxinology/
They are grate at captivity.
They are calm; they don’t jump out of the cage and start crawling allover (like some cobras and other Elapidae might), they stay calmly on the hook when moving them.
They are good eaters, and the babies start feeding quite easily.
They don’t make a lot of mess when [bleep]ting (like some large bitis species might).
I think they are quite similar to all other mid to large size Vipera species in these matters (and Crotalus as well).
Please tell me if you have any other questions.