does anyone know if and when there will be more episodes of black blood brothers?

Answer 1

Like alot of anime I can see why you think there would be or should be more episodes, since it didn't have a good conclusive ending.

Unfortunatly, there haven't been any official announcements anywhere about a continuation of the series.

So, the answer is no, there isn't going to be any unless the fandom in Japan for it was large enough to warrent more episodes to be made (so far dosen't seem that way).