There are many clans and even more sub-clans. You do not know the exact amount. The Shaman has taught you of the local clans mostly.
The Nurks are one of the few seafaring clans. Most Vudans abhor the world's seas, being large insects and preferring to stay on dry land. While your incredible constitution makes it very hard to drown you, none of you are great swimmers. Except, again, some of the Nurks.