Toxicity assessment for the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia.

In this study, we assessed the toxicity of the horseshoe crab Carcinoscorpius rotundicauda collected from Cambodia within two successive months during rainy (April-May) and dry (December-January) seasons, respectively. Toxicity assessments of the collected specimens by standard mouse bioassay showed marked individual variation, and their toxin profiles by liquid chromatography/mass spectrometry (LC/MS) revealed tetrodotoxin (TTX) was the main toxin while no paralytic shellfish toxins (PSTs) were detected. All specimens were toxic and the highest toxicity values were 315, 113, 60, 47, 44 and 38 mouse units (MU)/g in the tissues of hepatic caecum, egg, viscera, muscle, intestine and testis, respectively. Although the current findings showed that the Cambodian C. rotundicauda was a moderately toxic species, they are not suitable for human consumption due to their toxicity. To the best of our knowledge, this is the first scientific study on toxic marine seafood ever investigated in Cambodian territorial waters.