The simplest way to tell the sex of a mullet is to inspect its middle section. If a white liquid is exuded on applying pressure, the fish is a male, but if the belly is round and juts out like a drum, it is probably a female.
交易完畢，立刻開艙取魚，辨別雌雄。最簡單的鑑別方法是「指壓法」：按住烏魚尾腹部，如果有魚白流出，就是雄魚；如果有黃色的卵粒流出，那就是雌魚了。