That’s crab paste, it’s black and you can eat it.

1. Crab paste is a collection of semen and organs in the spermatheca of male crabs. It is also a sign of the strength and maturity of male crabs. The natural state of crab paste is a bluish-white translucent jelly-like liquid; after steaming, it becomes a translucent, sticky, and slightly greasy gel.

2. There are two types of crab paste: river crab paste and sea crab paste. River crab paste is slightly sweet, while sea crab paste is slightly fishy. It contains water, protein, fatty acids, vitamins and other ingredients.