The red egg crab is a poisonous sea crab that must not be eaten; be careful to identify it correctly.

The red egg crab is a marine crustacean in the family Xanthidae, genus Atergatis. It is widely distributed in the tropical and subtropical waters of the Indian Ocean to the Western Pacific, and is also fairly common around rocky reefs and coral reefs along the southern coast of China. Its carapace is nearly round, smooth and convex on the surface, and its body color is mostly pink or orange-red. Its claws are thick and strong, and its overall appearance somewhat resembles some commonly eaten crabs.

This crab mostly lives in rock crevices from the intertidal zone to shallow sea waters. During the day it often hides, and at night it comes out to move about and forage, feeding mainly on algae and small benthic organisms. Because it moves relatively slowly, it relies mainly on toxins accumulated in its body to defend against natural enemies, which is also a fairly common characteristic of members of the family Xanthidae.

Special attention should be paid to the fact that the red egg crab often contains marine biotoxins, and these toxins are heat-resistant, so ordinary steaming and boiling cannot completely destroy them. Eating it may cause poisoning, and in severe cases can harm health. For this reason, although it is called a crab, it is not suitable for the dining table.

Because its appearance is similar to some edible crabs, when shopping at the market or foraging by the sea, do not judge whether an unfamiliar crab is edible based only on its appearance. Understanding the toxic characteristics of the red egg crab not only helps avoid the risk of accidental ingestion, but also deepens understanding of marine biodiversity.