PURPOSE: To obtain the title device capable of automatically selecting fishes and shellfishes classified by weight and pulling up efficiently and inexpensively without requiring hands, having specific constitution of taking advantage of a phenomenon wherein longer the size of fishes and shellfishes is more sensitively rejective to lower applied voltage.

CONSTITUTION: First, an electric voltage to be rejected by fishes and shellfishes of ≥ given size is applied to two electrodes set to from an electric field zone 14. Then, fishes and shellfishes are put up to the electrical field zone 14 by a rousing net 13 and only fishes and shellfishes of ≥ given size which reject the electric voltage of the electrical field zone 14 and stop before the electrical field zone 14 are pulled up by a raising net 15 equipped in front of the electrical field zone 14 to constitute the objective device.