There are 1 pairs of monocular eyes at the front, 1 pairs of longitudinal ridges at both sides, 1 pairs of compound eyes with mouths and 6 pairs of appendages. The first two pairs are appendages of the head, and the 1 pair is short and consists of three segments, which are claw limbs. The second pair grows up and consists of six segments, which are called feet and whiskers. The two segments at the ends of larvae and females are chelates, and the ends of males are hooks and hoops. The other four pairs are called chest limbs, which are located on both sides of the mouth. Basal ganglia often have barbs to help eating, while the latter pair are suitable for digging holes and crawling in the sand. The total length is about 70 cm and the width is about 30 cm. Female adults generally weigh more than 2 kilograms.
Horseshoe crabs in China generally live in sediments at the bottom of the sea, and mainly eat worms and mollusks without shells. It has a special crawling action, wrapped in a carapace, like an armored soldier, with eyes on his back and hands and feet hidden under his stomach. When crawling on the ground, dancing a triangular tail that is sharp and looks like a sword in a samurai's hand, it is extremely interesting to climb first and then jump. It can also swim freely in the water with its belly feet, and it can also drill into the mud with the aid of the tail of the sword. Its long tail is not only a useful tool, but also a powerful weapon to defend against enemy damage.
Cultural connotation of Chinese horseshoe crab
Although Chinese horseshoe crab is ugly, it has a very unique "love". In particular, male horseshoe crabs are very devoted to "love". Once they find a partner, they are inseparable and hook the back of the female horseshoe crab with their claws. The obese female horseshoe crab hobbles in the ocean world with his younger male horseshoe crab on his back. Fishermen found a strange and interesting phenomenon: once the female horseshoe crab is caught, the male horseshoe crab always stays where it is, and is caught with the female horseshoe crab, which is called "underwater mandarin duck". If only one horseshoe crab is caught, the fisherman will think it is unlucky. If it is not released, it will "ask for trouble" and put it back into the sea.
The blood of Chinese horseshoe crab is blue, which is caused by copper ions, and it has the characteristic of coagulation when it meets the virus. Based on this discovery, scientists extracted "limulus reagent" from the blood of limulus, which was used as a monitoring agent for toxin pollution in pharmaceutical and food industries to detect whether the internal tissues of human body were infected by bacteria.
Chinese horseshoe crab