"Will I feel it if one
bites me?" Probably not. But that's not
because it has an anesthetic in its saliva, for which Mark says there's
no scientific evidence. Rather, he says, it's because your waterlogged
legs are desensitized. There's another reason you won't feel the
bite—the giant Amazonian leech doesn't bite. It stabs. Unlike the
jawed leeches, including the famed medicinal leech (Hirudo medicinalis), whose three miniature jaws work in tandem to slice
your skin open, H. ghilianii is a so-called proboscis leech. It has a muscular tube up to six inches long—Mark dubs
it a "tongue straw"—that it jabs into your flesh
hypodermically. "It can go rather deep into tissue," he notes. And
its saliva releases an anticoagulant that keeps your blood flowing long after
you scrape the leech off, as you can see here.
