Main nutrients: the protein content in fish is 15-20%, of which the content of scallop, chub and yellowtail is higher, at 18% or more. A catty of yellowtail in the protein content is about equal to 1.2 pounds of eggs or 7 pounds of pork in the content. Pomfret has a lower protein content of about 11.6%. Other aquatic plants and animals also have more protein content, such as shrimp for 20.6%. River shrimp is 17.5% river crab is 14.6%, kelp is 8.2%, seaweed 20.3%. Fish protein utilization rate of up to 85 ~ 90%. Fish fat content of 1 to 10%, generally less than 5%, but bream up to 15%, anchovies for 17%, other aquatic animals for 1 to 3%.　The content of vitamin B1 in fish is generally low, because fish contains thiaminase, which can break down and destroy vitamin B1. Vitamin B2 and niacin in eel and crab content, such as eel in the niacin content of 3.7 mg / 100 grams, vitamin B2 up to 0.98 mg / 100 grams. Vitamin A is more abundant in shrimps, crabs and clams, with 5,900 IU/100 g in crabs. Aquatic plants also contain high levels of carotenoids. Fish contains almost no vitamin C. Seafood contains more inorganic salts than meat, generally 1-2%, mainly calcium, phosphorus, potassium and iodine, especially rich in iodine, such as kelp containing iodine up to 24 mg/100 g. In addition, it is rich in iron, up to 150 mg/100 g. In the oyster also contains copper, up to 30 mg / 100 grams. Shrimp skin calcium up to 991 mg / 100 grams, is more than 100 times the calcium content of meat food.