There are really many reasons you dont see many CB hots.

Over abundance of cheap imports and people not willing to spend more on cb

Most venomous are quirky when it comes to breeding. They tend to be much more difficult than snakes you see commonly bred.

Mangroves just arent as commonly kept and those that do keep them dont keep Higher numbers of animals it will require to determine the tricks of their breeding.
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Dan S.
Crotalus & Company
Venom-Center Your Complete Venomous Community
Wisconsin Reptile Community