College of Marine Sciences;
Shanghai Ocean University;
Shanghai 201306;
China;
National Distant-Water Fisheries Engineering Research Center;
Shanghai Ocean University;
Shanghai 201306;
China;
The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources;
Ministry of Education;
Shanghai Ocean University;
Shanghai 201306;
China;
School of Marine Sciences;
University of Maine;
Orono;
Maine 04469;
USA;
Collaborative Innovation Center for National Distant-Water Fisheries;
Shanghai 201306;
China;
beak; standardized; methods; discriminant; analysis; Illex; argentinus; Ommastrephes; bartramii; Dosidicus; gigas;