Horseshoe crab is poisonous. The meat of horseshoe crab contains a macromolecular non-specific protein sensitizing substance. Eating horseshoe crab can cause skin allergic rash, redness, swelling and itching. In severe cases, it will lead to allergic shock or fatal toxic reaction, and the mortality of poisoning is high.
Horseshoe crab, also known as tachypleus amebocyte, belongs to a marine arthropod of the order of limb mouth and sword tail. The tachypleus amebocyte is like a crab. Its body is cyan brown or dark brown. It is covered with a hard shell. It has four eyes, two of which are compound eyes. There are two small eyes 0.5mm in front of the head and chest armor. It is most sensitive to ultraviolet light and is only used to sense brightness. There are a pair of large compound eyes on both sides of the head and chest armor. Although tachypleus amebocyte lysate can flap its gills back down to push its body to swim, it usually bends its body into an arch, drills into the mud, and then pushes its body forward with its tail sword and the last pair of feet.
Horseshoe crab is not a real crab, but a primitive arthropod. They have a wide disc-shaped body and a slender needle like tail. Their ancestors can be traced back to the Cambrian period, but it was not until the Jurassic period that they developed the appearance of horseshoe. Although there are still five species of horseshoe crabs, they have been less common since the post Cretaceous period.