How do the nostrils of highly specialized true sea snakes (*Hydrophiinae*) differ from those of sea kraits?

Answer

True sea snakes feature valvular nostrils situated on the top of the snout

Highly specialized true sea snakes have valvular nostrils on the top of the snout for efficient surface breathing, while sea kraits have lateral nostrils.

How do the nostrils of highly specialized true sea snakes (*Hydrophiinae*) differ from those of sea kraits?
seaanimalclassificationreptilesnake