Machine for grading and sorting fish, in particular fish from the salmonidae family

A machine for grading and sorting fish comprising:

• (a) a frame including an upper part and a lower part;
• (b) an elongate tank supported at the lower part of the frame, the tank being defined by a plurality of successive transversal compartments along the longitudinal axis of the tank, each compartment being provided with an outlet tube;
• (c) at least one longitudinal grading channel disposed at the upper part of the frame, the channel including a passage section for advancing the fish along a given direction, an upper portion, an open lower end in communication with the compartments, sloping side walls for causing displacement of the fish with their tails directed downwardly through the open lower end, an adjustable cross-section which increases in the given direction, means for spraying fluid on the fish, and overlapping plates for closing off the upper portion to prevent the fish from jumping vertically therethrough;
• (d) a supply tank for supplying live fish to be graded and sorted, one end of the channel being in communication with the supply tank for receiving live fish therefrom;
• and
• (e) an endless conveyor belt associated with the channel and including a plurality of thrust bars, the thrust bars being caused to successively arrive in transversal position along the length of the passage section for advancing fish therethrough in the given direction.