Situations and Knowledge of Poisoning from Horseshoe Crab Consumption

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Khachonyut Bangtamai
Pornchai Sithisarankul
Hirunwut Praekunatham


            Horseshoe crabs are popular marine animals that are consumed as food, and most people do not know that they are poisonous. There are two species of horseshoe crabs in Thailand: round-tailed horseshoe crab (Carcinoscorpius rotundicauda) and square-tailed horseshoe crab (Tachypleus gigas). Their habitats are on the coast or along the mangrove canals. Most of their food are shellfish and seaworms. Every year, they come to lay their eggs on land along the beach during February and September. The poison in horseshoe crab is tetrodotoxin, that is not heat labile, and has an inhibitory effect on nerve signaling. Most of the poisoning symptoms develop within 6 hours but may delay to 12 - 24 hours. Currently, symptomatic treatment and assisted ventilation are the main treatment. Regarding reports from various institutions, poisoned cases from horseshoe crabs have been reported since 1966, and there were 189 poisoned cases, 8 fatal cases reported during January 1995 and February 2021. The knowledge of toxicology has been collected, but a systematic compilation of the incidents from horseshoe crab poisoning has not been recorded. Deeper knowledge and understanding of the horseshoe crab may lead to proper consumption of natural resources and inform guidelines in the prevention and symptom relief from poisoning.

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