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

Hélène Taiana Darius,Manoëlla Sibat,Philipp Hess,Mireille Chinain,Jérôme Viallon,Philippe Cruchet,Clémence Mahana Iti Gatti,Taina Revel

doi:10.3390/md19110644

Hélène Taiana Darius, Manoëlla Sibat + Show 6 more

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https://doi.org/10.3390/md19110644

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Abstract

Ciguatera poisoning (CP) cases linked to the consumption of deep-water fish occurred in 2003 in the Gambier Islands (French Polynesia). In 2004, on the request of two local fishermen, the presence of ciguatoxins (CTXs) was examined in part of their fish catches, i.e., 22 specimens representing five deep-water fish species. Using the radioactive receptor binding assay (rRBA) and mouse bioassay (MBA), significant CTX levels were detected in seven deep-water specimens in Lutjanidae, Serranidae, and Bramidae families. Following additional purification steps on the remaining liposoluble fractions for 13 of these samples (kept at −20 °C), these latter were reanalyzed in 2018 with improved protocols of the neuroblastoma cell-based assay (CBA-N2a) and liquid chromatography tandem mass spectrometry (LC–MS/MS). Using the CBA-N2a, the highest CTX-like content found in a specimen of Eumegistus illustris (Bramidae) was 2.94 ± 0.27 µg CTX1B eq. kg−1. Its toxin profile consisted of 52-epi-54-deoxyCTX1B, CTX1B, and 54-deoxyCTX1B, as assessed by LC–MS/MS. This is the first study demonstrating that deep-water fish are potential ciguatera vectors and highlighting the importance of a systematic monitoring of CTXs in all exploited fish species, especially in ciguatera hotspots, including deep-water fish, which constitute a significant portion of the commercial deep-sea fisheries in many Asian–Pacific countries.

Highlights

Throughout the tropical and subtropical Indo–Pacific, deep-water fish reside near the seafloor of oceanic islands and continental habitats, on the drop-offs of deep slopes and seamounts, and sometimes at depths of up to 1500 m [1,2,3]
Using the mouse bioassay (MBA), four specimens and five pooled samples belonging to the golden grouper Saloptia powelli (n = 15/15), the reticulate grouper Epinephelus tuamotuensis (n = 1/2), and the Crimson jobfish Pristipomoides filamentosus (n = 1/2) were found negative (Table 1)
The total flesh toxicity values ranging from 0.005 to 0.2 mouse unit per gram of fish flesh (MU g−1 ), which can be converted to 0.04 to 1.4 μg CTX1B eq kg−1 fish flesh, showed comparable toxicities as reported in coral reef carnivorous fish collected in the Asia-Pacific region [42,43,44,45]

Summary

Introduction

Throughout the tropical and subtropical Indo–Pacific, deep-water fish reside near the seafloor of oceanic islands and continental habitats, on the drop-offs of deep slopes and seamounts, and sometimes at depths of up to 1500 m [1,2,3]. Most species fished for human consumption belong to the Epinephelidae (grouper), Lethrinidae (emperor), and Lutjanidae (snapper) families [2,3,4,5,6,7]. These large carnivores are characterized by slow growth, delayed maturity, extended longevity, and high site fidelity, making them vulnerable to fishing pressure [4,8]. In the snappers belonging to Etelinae subfamily (Lutjanidae family), the genera Aphareus, Aprion, Etelis, and Pristipomoides represent the main targeted species and are commercially important marine species in many tropical–subtropical fisheries as well [4,9]. It is noteworthy that they account for a large proportion of catches of the Hawaiian (Deep Seven Bottom fish complex) and Japanese deep-water fisheries [2,3,4,5,6,7,10,11]

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