Known as crab yolk is the liver and pancreas of river crabs, which is brownish yellow and pulpy when cooked.

Unproduced shrimp in the brain, female shrimp to maturity, the head and neck will contain shrimp yolk, so there is shrimp yolk shrimp must be female shrimp, but no shrimp yolk is not necessarily male shrimp, female shrimp immature can not see shrimp yolk. Female shrimp in pregnant eggs before the shrimp head and neck containing shrimp, commonly known as red-headed boy. Lobster yellow a lot of flavor is the best of lobster.

Suzhou and Zhejiang summer crab market is known as the "June yellow" gonadal undeveloped crab, its body only see a lot of crab yellow and no crab paste. When the water temperature drops in September, river crabs begin to mature and molt, and the gonads gradually develop. At this time, the crab yolk gradually shrinks and the crab paste gradually increases. When the crab yolk and crab paste about half of each, color, fragrance, freshness, tenderness should be