All fish have fishing lines, one on each side of their bodies. Some fish will smell fishy if they are not deodorized, which will affect the taste. Removal method: cut a knife at the gill and tail of the fish, and there is a white spot at the cutting position, which is the fishing line. Just grab the line, gently pat the fish on the back, and then pump it out, preferably starting from the fish's gills, both sides are the same.

Extended data:

The fishing line is actually the side line of the fish. The groove or tubular skin receptors peculiar to vertebrates, fish and aquatic amphibians are called lateral lines. The tube is filled with mucus, and the sensilla is soaked in mucus. The current hits the fish, affecting the mucus in the tube, transmitting external stimuli to sensory cells, and then transmitting them to the nerve center through sensory nerve fibers.

The body side tube is perforated on the lateral line scale at regular intervals to communicate with the outside world, which has the functions of hearing, feeling the water flow and positioning.