Ciguatera toxins in wild coral reef fish along the southern coast of China

Ciguatera toxins (CTXs) in wild coral reef fish collected from the southern coast of China were analysed. Cigua-Check kits were used for primary screening. Mouse bioassay was used to quantify toxins of the samples identified as positive by the Cigua-Check kit. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to further analyse P-CTX-1 of ciguatera toxins in the samples identified as positive by the mouse bioassay. The mouse bioassay showed that ciguatoxic fish existed in all six sampling sites, and 47.8% of the samples were confirmed to be contaminated with CTXs. The implicated species largely belonged to Chaetodontidae, Scaridae, Holocentridae, Lutjanidae and Serranidae. The toxicities varied from 0 to 169ng P-CTX-1kg(-1) fish flesh according to mouse bioassay. There was no significant correlation between fish toxicity and fish weight, length and feeding habits. The accuracy rate of the Cigua-Check kit in judging toxicity or non-toxicity was up to 95.7% according to the mouse bioassay. However, the Cigua-Check kit and mouse bioassay differed significantly with respect to measures of toxicity. According to HPLC-MS/MS, no P-CTX-1 was identified in any of the samples that the mouse bioassay identified as positive.