Did the guy at the pet store tell you it was a myth? I dont think its a myth. Pacmans are hard to sex young but I have three males and they all have the black throats. I have heard all three call. The two females I have look like the one pictured. Still to this day I have not heard the presumed females call with the males in sight or even when the males have calling battles. Also, another reason why I think its a female is because it had grown considerably in a shor time under his care. Females grow alot faster then males do. Females are always generally larger then males.