fish use a lot of "posturing", and many form shoals, schools, harems, etc. it's all form of communication, maybe not necessarily "talking". my clown goby was EXTREMELY shy, when I put in the yellowtail damsel, I was worried that the goby would completely disappear out of fear of the damse...but the damsel obviously gave off a "good vibe" because they swim around together, and the goby pretty much follows the damsel's lead in everything they do...that's "talking"