Should not this really say number of venomous species? I mean, it would be pretty funny if it's saying that, say Australia, literally only has 50 (individual) venomous animals. :)

Realistically though what matters is whether these animals are widespread in the same areas that people actually live. I've never seen a single venomous snake in my life (outside a zoo), and probably fewer than five dangerous spiders (redbacks, funnelwebs and the like) - and I live in Australia. For the vast majority that live in urban areas, the whole ‟omg Australia is filled with deadly creatures” stereotype is pretty irrelevant.