Phil, I had a dusky that lived for many years...awesome fish with a lot of personality. IMO they build and keep their burrows better than yellowheads and are better builders with their rocks and shells that they gather up. They're always rearranging too. They're also hardier than the yellowheads and don't jump as much.
Even though they have a big mouth they are not aggressive but will bluff with it wide open as they scurry back into their burrow if another fish gets too close. These guys are mouth breeders too, I believe, but I could be mistaken on that...another reason for the big mouth! Raising kids causes big mouths....hmmmm...could get in trouble for that one if my daughter catches me typing this
He ain't ugly, he's beautiful!