In general, temperatures of 20 ° - 22 ℃, and 3.2 % -3.3 % salinity provide the most ideal conditions for mullet, so the earlier the cold front arrives, the more northerly the fishing grounds are.
因為據說，皮刀魚是烏魚群的先頭部隊，皮刀魚的出現，就是烏魚來臨的癥兆。其實，這種說法並不完全正確。