After getting the SW bug from a friend and finding out about these beautiful creatures, I've been fixated for the past 8 months on anything mantis related. Op, I'll agree that there's conflicting info out there, but I think the worst area to collect ANY info from is an LFS. AA and other similar sites will give you your best shot at the most reasonable answer. And a couple hundred uneducated guesses.
A few things I've seen in my research that have been repeated in regards to proper husbandry for a Mantis are the following:
Minimum of at least a 30g and preferably a 40g.
Deep Sand Bed (DSB)
A mature tank
Above all other things, DO NOT HANDLE !!!
As Sniper pointed out, it is ILLEGAL (without a permit and dealing with all levels of red tape) to remove any animals from any natural environment. It is also ILLEGAL to introduce non native species and in most cases, native species as well.
IMO, I would do more research on them for a bit and continue asking questions. Slow down a little. Everything in the aquatics world (and many others) takes time and patience. Without either, it'll cost a whole lot more of everything in the end and you'll still be behind. Move those clowns into something bigger. If you want a shrimp, try a pistol and goby pair. It'll keep you very entertained while you read up on other things.
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