Toxicity of Brachuryan crabs in India

Crabs are the most abundant macrofauna in the coastal environment, and may belong to many different species and even families. Some of these crabs contain specialized protein substances that act as toxins. Toxins, especially proteins that are produced by living cells or organisms, are poisonous substances. Toxins can be divided according to their pharmacological effects (neurotoxins, myotoxins, hepatotoxins, nephrotoxins, hematological toxins, and locally acting toxins) and their sources, such as snakes, scorpions, mussels, spiders, marine creatures, or sea anemones. Crab toxins are heat resistant and are found in the crabs’ viscera. Hence, they cannot be destroyed by cooking, and there is also no known treatment available for these toxins. The only alternative is to educate fishermen, holiday makers, and seafood consumers to recognize these poisonous species and avoid them. Several toxins identified from crabs are neurotoxins, related to tetradotoxin (TTX), which is found in pufferfish. Other toxins include saxitoxin (STX), neurosaxitoxin (NeoSTX), and some unidentified toxins. Some poisonous crabs possess a mixture of these toxins. This article describes the toxins and Brachuryan crabs producing toxicity.