The ovaries and digestive glands in crabs are orange and delicious. Crab yolk is not a crab egg. Although its composition is basically the same as crab roe, there are essential differences between them. Crab yolk does contain eggs that have not been excreted, but there are other crab organs, glands, tissue fluids and other substances, not just crab eggs. When the crab roe becomes large and bright orange, it shows that the gonad of the female crab has matured. At this time, crab eggs are produced and excreted, and the egg cells left in the gonads in the body still belong to crab yellow.

Crab yellow is rich in nutrients such as protein and phospholipids, but it also contains high content of oil and cholesterol. Crab yolk can be made into many delicious foods, such as crab yolk porridge. Nanjing has a famous snack-Dragon Robe and Crab Yellow Soup Bao, and Shanghai has a famous delicious snack-Crab Powder Steamed Bao. As the name implies, the main ingredient is crab roe. There are two kinds of crab yellow: river crab yellow and sea crab yellow.

According to the "Food Classics", female swimming crab has the effects of appetizing, moistening lung, tonifying kidney and strengthening yang, nourishing blood and promoting blood circulation. Among them, crab roe has the highest nutritional value. Rich in trace elements, collagen, calcium, phosphorus and other essential nutrients, it is known as "gold in the sea".

Male crabs have seminal vesicles, and white material in them is sperm. The sperm and sex organs of male crabs are crab paste.

Crab paste may also be fat. Because in order to prepare for the winter, male crabs gradually accumulate fat and grow into crab paste (commonly known as crab oil). Peeling off the shell of the male crab, you can see that there is a white sticky thing in the crab shell and crab tuo, which is crab paste (crab oil). After cooking, crab paste becomes translucent. The more crab paste, the stronger the male crab.