http://www.gov.sg/moh/mohiss/poison/pictor.html Lophozozymus pictor (Thunder Crab) -------------------------------------------------------------------------------- It is a confirmed toxic species. It could be found inhabiting the coral reef beds in the southern islands off Singapore. An adult crab weighs about 100 grams and 10 cm in width. It is usually brightly coloured and has mosaic patterns on its shell and as such is also know as the mosaic crab. Locally this is commonly called "Thunder Crab"; the Australians call it the "Red and White Reef Crab". Several cases of human fatality in association with its consumption have been documented. The crab is highly toxic and to date there is no known antidote against such poisoning. Seek immediate medical treatment in any suspected case of poisoning. Distribution: Singapore, Philippines, Indonesia and Australia. Domoic Acid (ASP) in Shellfish What is domoic acid? Domoic acid is a naturally occurring toxin produced by microscopic algae, specifically the diatom Pseudo-nitzschia pungens. Shellfish and crab ingest this algae, where the toxin concentrates. Significant amounts of domoic acid can cause Amnesic Shellfish Poisoning (ASP) in humans. ASP is transmitted by eating contaminated molluscan shellfish and crab. http://www.doh.wa.gov/ehp/sf/Pubs/DomoicAcid.htm