How do we distinguish between semen (mani) and prostatic fluid (madhy), and does each have a scent?

The semen that necessitates ghusl (ritual bath) is discharged either during sleep (whether one remembers the wet dream or not) or while awake due to intercourse or its foreplay. It is a viscous fluid that exits with a gush and desire, followed by a sensation of relaxation. Its smell resembles that of a date palm spathe or dough. As for madhy (pre-seminal fluid), it is a viscous fluid, thinner than semen, discharged after sexual arousal, and often intermittently. It necessitates washing the male organ and invalidates ablution (wudu').