Amphioxus (Mejiro) is a chordate of the genus Amphioxus of the order Amphioxidae and family Amphioxidae.

Amphioxus (Mejiro) is a chordate of the genus Amphioxus of the order Amphioxidae and family Amphioxidae. There is a lip on the ventral surface of the front end of the body, and there are tentacles on the edge of the lip. There is a dorsal fin formed by folded skin along the midline on the back, which is closely connected to the wider caudal fin at the end of the body. The ventral side of the caudal fin is connected to the front anal fin. At the same time, there are ventral folds on both sides of the ventral surface of the body; there are no scales on the body; because the body is slender and flat on the sides, like a willow leaf, with pointed ends, it looks like a fish but not a fish, and is translucent, like a slightly reddish worm. There is no obvious differentiated head, so it is commonly known as "headless fish".

Amphioxus is not actually a fish. It is an animal between invertebrates and vertebrates. Amphioxus is the earliest chordate, but Amphioxus has hardly evolved at all and still maintains the shape it had 530 million years ago. Amphioxus is a rare and valuable marine wild cephalochordate, and is listed as a Class II key protected object by China.

Amphioxus has many nutritional values. Here are the general nutritional facts of bonito:

1. Amphioxus has a high protein content, is rich in iodine, iron and phosphorus, and has a low fat content. It is a nutritious and delicious marine treasure.

2. The body fat content of amphioxus is low, but the unsaturated fatty acid content is relatively high, accounting for about 1.6% of the wet mass. Research results show that the protein content of amphioxus is higher than that of pomfret, Hairtail, croaker, shrimp and oyster. The total protein content in the adult body of male amphioxus is 19.05% and that of female is 19.73%; in addition, Wenchang Fish is rich in all eight essential amino acids required by the human body; the ratios of essential amino acids to total amino acids and non-essential amino acids exceed the requirements of 0.40 and 0.60 respectively specified by FAO/WHO standards. It can be seen that the protein and amino acid nutritional value of amphioxus is relatively high. In addition, amphioxus is rich in fat-soluble vitamins A, vitamin E, and water-soluble vitamins B1, B2, and vitamin P. Vitamin B2 is one of the nutrients that Chinese people are prone to lack in their diet. Compared with other seafood, amphioxus has a significantly higher vitamin B complex content and a higher vitamin E content. Among the amino acids, aspartic acid, glutamic acid, glycine and alanine are the main factors that determine the umami taste of food, and are collectively called flavor amino acids. The contents of flavor amino acids per 100 grams of adult amphioxus are 4.74769 and 4.9666 g respectively, which are relatively abundant. Therefore, amphioxus tastes delicious and has potentially high economic value.

3. Biochemically, it can be seen that it has the creatine phosphate substance of all vertebrates, but it does not have the hemoglobin and iron compounds of all vertebrates. Amphioxus contains a special vanadium element.

Amphioxus sashimi is a Japanese dish made with fresh amphioxus. Here are the general steps for making amphioxus sashimi:

1. Choose fresh amphioxus: Make sure to choose fresh, high-quality amphioxus. The fish should have no odor and the skin should be shiny.

2. Cleaning and Handling: Rinse the amphioxus and dry gently with paper towels or absorbent paper. Then, remove the scales, guts, and gills. Cut off the fins to avoid affecting the taste.

3. Cut the fish: Use a sharp knife to cut the amphioxus into sashimi slices. The thickness and size of the sashimi slices can be determined based on personal preference and eating occasion.

4. Prepare condiments: You can prepare some traditional Japanese sashimi condiments, such as soy sauce, mustard sauce, soy sauce dipping sauce, yuzu peel, ginger, etc. These condiments can enhance the flavor of amphioxus sashimi.

5. Plating and decoration: Arrange the sliced amphioxus sashimi neatly on the plate. You can garnish with sliced grapefruit peels, ginger or other suitable decorations to add beauty.

6. Enjoy the sashimi: Amphioxus sashimi is best eaten shortly after preparation to maintain optimal taste and freshness. Dip the sashimi slices in an appropriate amount of soy sauce or mustard sauce, then taste slowly to experience the delicious taste of amphioxus.

Preparing amphioxus sashimi requires some knife skills and experience, be sure to use a sharp knife and handle it carefully to ensure safety. Also, for food safety reasons, make sure to use fresh lancelet and maintain hygienic conditions during preparation and storage.