Characteristic Distribution of Ciguatoxins in the Edible Parts of a Grouper, Variola louti

Abstract

Ciguatera fish poisoning (CFP) is one of the most frequently encountered seafood poisoning syndromes; it is caused by the consumption of marine finfish contaminated with ciguatoxins (CTXs). The majority of CFP cases result from eating fish flesh, but a traditional belief exists among people that the head and viscera are more toxic and should be avoided. Unlike the viscera, scientific data to support the legendary high toxicity of the head is scarce. We prepared tissue samples from the fillet, head, and eyes taken from five yellow-edged lyretail (Variola louti) individuals sourced from Okinawa, Japan, and analyzed the CTXs by LC-MS/MS. Three CTXs, namely, CTX1B, 52-epi-54-deoxyCTX1B, and 54-deoxyCTX1B, were confirmed in similar proportions. The toxins were distributed nearly evenly in the flesh, prepared separately from the fillet and head. Within the same individual specimen, the flesh in the fillet and the flesh from the head, tested separately, had the same level and composition of toxins. We, therefore, conclude that flesh samples for LC-MS/MS analysis can be taken from any part of the body. However, the tissue surrounding the eyeball displayed CTX levels two to four times higher than those of the flesh. The present study is the first to provide scientific data demonstrating the high toxicity of the eyes.

Critical Review and Conceptual and Quantitative Models for the Transfer and Depuration of Ciguatoxins in Fishes

“…Our growth dilution model assumes the concentration of ciguatoxins are homogeneous throughout the flesh of fish, and this is supported by recent findings that P-CTX-1, -2 and -3 were similarly distributed throughout the fillets of yellow-edge coronation trout ( Variola louti ) caught from Okinawa [ 158 ]. However, it is possible that the concentrations of ciguatoxins across the tissues of Spanish mackerel fillets could vary, as Li et al [ 72 ] have recently shown that much higher concentrations of ciguatoxins can accumulate in the skin compared to the muscle in goldspotted rockcod ( Epinephelus coioides ).…”

“…However, both P-CTX-1 and P-CTX3C analogs have been detected from red bass ( Lutjanus bohar ) [ 31 ], amberjack ( Seriola dumerili ) [ 174 ] and moray eel ( Gymnothorax javanicus ) [ 22 ], showing that both families of toxins can bio-accumulate into higher trophic level fishes. Oshiro et al [ 158 ] could not detect P-CTX3C from five yellow-edge coronation trout ( Variola louti ) caught from Okinawa and contaminated with P-CTX-1, -2 and -3. As yet, P-CTX3C analogs have not been detected from dinoflagellates or fish from Australia.…”

Extraction and LC-MS/MS Analysis of Ciguatoxins: A Semi-Targeted Approach Designed for Fish of Unknown Origin

“…Therefore, the enzyme protocol has been demonstrated as suitable for performing single determinations. According to a study by Oshiro et al (2021), CTXs are almost equally distributed within the fillet, so the error of sampling or inhomogeneity should not impair the results in the case of a single determination [51].…”

Deep-Water Fish Are Potential Vectors of Ciguatera Poisoning in the Gambier Islands, French Polynesia

“…Of note, 52-epi-54-deoxyCTX1B and 54-deoxyCTX1B were originally given the names CTX-2 and CTX-3, respectively [46]. For the record, CTX1B and the two deoxy analogs of CTX1B (Figure 4), 52-epi-54-deoxyCTX1B and 54-deoxyCTX1B, are usually found in a variety of great carnivores such as moray eels, barracudas, groupers, snappers, Spanish mackerels, or jacks in the Asia-Pacific region [43][44][45][46]51,[56][57][58][59][60][61][62][63][64]. However, these analogs were also reported in herbivorous and omnivorous coral reef fish species [53,61].…”