The crab paste is not green in color. This phenomenon occurs because the internal organs of the crab are contaminated.

The water environment in which the crabs are bred extremely affects the quality of the crabs, so if the water resources are contaminated by metal ions, the crab paste may turn green. The organisms in the water will have a kind of sporozoite parasite, and if the parasite that enters into the body of the crab from its gills is parasitized on the intrahepatic bile ducts, leading to bile leakage, which may result in the green color of the digestive glands and the mucous membranes, i.e., the crab paste will turn green.

Crab paste is a collection of semen and organs from the seminal vesicles of male crabs and a sign of their strength and maturity. In its natural state, crab paste is a greenish-white translucent jelly-like liquid; after steaming, it is a semi-transparent, sticky, and a bit greasy gel.

Expanded Information

The cephalothoracic armor of the green crab is slightly oval, with a smooth surface, slightly elevated in the center, and inconspicuous zoning. The surface of the armor and appendages are greenish-marginal in color. There is an obvious "H"-shaped indentation between the gastric and cardiac regions on the dorsal surface, and the frontal surface has four prominent triangular teeth, which are more prominent than the inner eye sockets, and there are nine medium-sized teeth on the anterolateral margin, with the last teeth being small and sharply protruding, pointing toward the front. Chelicerae strong, both chelicerae asymmetrical.

Long segment with 3 spines on anterior margin and 2 spines on posterior margin; carpal segment with 2 blunt teeth on outer terminal margin and 1 strong spine on inner terminal angle; metacarpal segment swollen and smooth, especially swollen in males, with 2 rondellar ridges on dorsal surface and 1 spine on its terminal end, and 1 lineal groove on inner and outer part of each of the knuckles, with a large space between the two fingers, and large, blunt teeth on inner margin.

The anterior and posterior margins of the first three pairs of pedipalpal phalanges are covered with short hairs, and the anterior and posterior phalanges of the last pair of pedipalps are flattened and pulpy, making them suitable for swimming. The male abdomen is broadly triangular, with the terminal margin of segment 6 concave, its margin straight, the lateral margins straight, and the terminal margin of the last segment bluntly rounded, while the female abdomen is broadly rounded.

The integrity of crab paste has nothing to do with its taste or nutritional value. In the wild, the yolk of female crabs grows fullest in September of the lunar calendar, and the crab paste (crab oil) of male crabs grows thickest in October.

Baidu Encyclopedia - Crab Paste

Baidu Encyclopedia - Green Crab