The LMBV can only be detected from laboratory testing, there are no certain external signs. The black spots on the bass are more than likely just a pigment, like a mole on humans. Sometimes you'll see bass with them all over the body making them look sort of calico colored. These are healthy fish, just have a few birthmarks. I always thought it would be cool to get one mounted like that. I've seen more of them this year than usual...not sure why.