Some time ago, a fisherman in the Penghu Islands, Taiwan, returned to port after a fishing trip and caught a crab with vibrant colors. Due to the rarity of this crab’s appearance, even experienced fishermen hesitated to eat it and checked online, discovering it was the most poisonous crab in the world.
The crab caught by the fisherman is a highly toxic species known scientifically as “Lophozozymus pictor”, also referred to as embroidered crab or mosaic crab. It is found in Australia, Singapore, the Malay Peninsula, and Hainan, China. Its shell is beautifully colored in red and white, but it harbors significant toxicity.
Scientists have demonstrated through experiments that the venom from a mature crab can poison 45,000 mice. There are recorded instances of fatalities due to its consumption, and cooking it at high temperatures for a short time does not eliminate the toxin.
The embroidered crab primarily inhabits the waters of Japan, Australia, Fiji, and Hainan (China), often found in intertidal zones, under rocks or coral reefs at depths of 30 meters.
The crab’s toxin is believed to come from its diet, such as toxic sea cucumbers. Although sea cucumbers do not possess obvious harmful organs, the organs and body structures of Cuvier in some sea cucumbers contain hemolytic toxins. Generally, these toxins are not harmful to humans; however, if the crab preys on sea cucumbers, endogenous bacteria will process the toxins and incorporate them into the crab’s meat.
The Queensland Agricultural Biotechnology Center conducted a study on its toxicity and found that this pure toxin has properties similar to those of sea anemone toxins and tetrodotoxin.
Research from the Diana zoology group at the National University of Singapore indicates that different parts of the embroidered crab exhibit varying levels of toxicity. The intestines and pancreas are more toxic, the flesh is less toxic, and the shell is slightly toxic or non-toxic. If kept in captivity for a period, the toxicity may decrease or even disappear, indicating that the toxin indeed comes from the diet.
In reality, it is not uncommon for poisonous crabs worldwide to be categorized into two types: high toxicity and low toxicity.
Additionally, there is a highly poisonous red crab known as Zhengzheng Aijie crab, which has a bright red body with small pale yellow swellings on the surface, concentrated around the eyes and the front margins of the shell. Occasionally found in the southern coastal waters of China, they are toxic due to consuming small pufferfish or poisonous fish.
