Boots,
Might I suggest adding a classified adds section to your website with links to individual pages for each subspecies of garter snake. On each subspecies page, people could post "wanted" or "for sale" adds for that particular subspecies. I think that having a page or two devoted to each subspecies makes shopping/selling a lot easier because people could go to individual pages rather than sorting through several pages of mixed species adds. That way your site could connect buyers and sellers more easily. Kind regards, Rick