Ichthulin is a term that refers to a protein found in fish muscle. It is used in various industries, including food, pharmaceuticals, and cosmetics. However, there are some synonyms for the word Ichthulin that are frequently used interchangeably. These include fish collagen, fish gelatin, and fish bioactive peptides. Fish collagen and gelatin are typically used in the food industry for thickening and stabilizing products. Meanwhile, fish bioactive peptides have potential health benefits, such as promoting skin health, reducing blood pressure, and preventing cardiovascular disease. Overall, Ichthulin is just one type of protein found in fish, and its synonyms can be used depending on the specific application or industry.