Female crabs are good.

"Nine females and ten males" refers to female crabs in September and male crabs in October. It is also called "September Tuan Navel and October Point".

The round navel is a female crab, and the pointed navel is a male crab. This means that female crabs are eaten in the ninth month of the lunar calendar, and male crabs are eaten in the tenth month of the lunar calendar. Therefore, in the ninth month of the lunar calendar, the digestive glands and ovaries of the female crab grow into crab roe to prepare for the winter and the need for reproduction in the coming year (the crab roe turns into crab roe in spring).

Life habits:

Foraging

Crabs spend most of their time looking for food. They are generally not picky eaters and will eat whatever food they can get with their pincers. They can eat small fish and shrimps, but some crabs eat seaweed and even animal carcasses and plants.

Competition

Crabs eat other animals, and other animals may also eat crabs. For example, humans treat crabs as delicacies, and water birds also eat crabs. Some fish are also like humans. Also like to eat crab legs. When young and immature crabs float in groups in the sea, they may be preyed upon by other marine organisms. Therefore, crabs must lay a large number of eggs when spawning to ensure the survival rate of the crabs.

Reproduction

They rely on female crabs to give birth to baby crabs, and each time the female crabs lay a large number of eggs, the number can reach millions or more. After these eggs hatch in the abdomen of the mother crab, the larvae can break away from the mother and float around with the coastal currents.

After several times of shelling, it grows into a big-eyed larvae. The big-eyed larvae then shells several times and grows into a young crab. The appearance of the young crab is almost the same as that of an adult crab. After several times of shelling, the big-eyed larvae grows into a crab. Then it turns into a crab. Most saltwater crabs discharge their eggs directly into the ocean without hatching after their eggs mature.

Body structure introduction:

Although crabs are small, they have all five internal organs. After removing the hard shell of the crab, we can find that the crab's body is protected by a shell. These shield-like shells are called carapace by biologists.

The body of the crab is symmetrical from left to right and can be divided into the forehead area, eye area, heart area, liver area, stomach area, intestine area and gill area. The two sides of the crab's body are connected by appendages. The appendages on the head are called antennae, which provide touch and smell functions. Some appendages have mouth functions, which are used to tear food apart and bring it into the mouth.

The crab's chest has five pairs of appendages, called thorapods. The pair of appendages in the front are equipped with strong claws, which can be used for foraging. The remaining four pairs of appendages are the crab's feet. Crabs rely on these four pairs of appendages to walk and move. Their walking appearance is unique and unique. Interesting, most of them are walking sideways instead of going straight forward. The exception is monk crabs, which walk straight.