The boss fish smells like ammonia because its blood contains urea.

Boss fish, scientific name is hole ray. Because its double fins are particularly developed, it looks like a large eagle with its wings spread out, so it was called the harrier in ancient times. Fishermen call them fish, with flat bodies, slightly round or oblong body disks, and generally a body length of 30 to 50 centimeters. The width of the body plate is greater than the length of the trunk, and the body weight is 1000-5000 grams. The tail is flat and narrow, the sides are well developed, the snout is medium long, and the tip of the snout is protruding. The anterior nasal valve is wide and extends to the outside of the mandible. The front of the posterior nasal valve protrudes in a semi-circular shape on the outside, forming a water inlet.

The tail of boss fish secretes amino acids and peptide proteins, which have certain effects on the central nervous system and heart, and have the effects of clearing away heat, reducing inflammation, and resolving knots.

To remove the ammonia smell of boss fish, the easiest way is to soak the killed boss fish in clean water for about 2 hours. Blanching with boiling water can also remove the ammonia smell.