Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia.
Toxins (Basel). 2022 Aug 3;14(8):534. doi: 10.3390/toxins14080534.
To begin to understand the impact of food chain dynamics on ciguatera risk, we used published data to model the transfer of ciguatoxins across four trophic levels of a marine food chain in Platypus Bay, Australia. The data to support this first attempt to conceptualize the scale of each trophic transfer step was limited, resulting in broad estimates. The hypothetical scenario we explored generated a low-toxicity 10 kg Spanish mackerel () with a flesh concentration of 0.1 µg/kg of Pacific-ciguatoxin-1 (P-CTX-1, also known as CTX1B) from 19.5-78.1 µg of P-CTX-1 equivalents (eq.) that enter the marine food chain from a population of 12-49 million benthic dinoflagellates ( sp.) producing 1.6 × 10 g/cell of the P-CTX-1 precursor, P-CTX-4B. This number of could be epiphytic on 22-88 kg of the benthic macroalgae () that carpets the bottom of much of Platypus Bay, with the toxin transferred to an estimated 40,000-160,000 alpheid shrimps in the second trophic level. This large number of shrimps appears unrealistic, but toxic shrimps would likely be consumed by a school of small, blotched javelin fish () at the third trophic level, reducing the number of shrimps consumed by each fish. The Spanish mackerel would accumulate a flesh concentration of 0.1 µg/kg P-CTX-1 eq. by preying upon the school of blotched javelin and consuming 3.6-14.4 µg of P-CTX-1 eq. However, published data indicate this burden of toxin could be accumulated by a 10 kg Spanish mackerel from as few as one to three blotched javelin fish, suggesting that much greater amounts of toxin than modelled here must at certain times be produced and transferred through Platypus Bay food chains. This modelling highlights the need for better quantitative estimates of ciguatoxin production, biotransformation, and depuration through marine food chains to improve our understanding and management of ciguatera risk.
为了初步了解食物链动态对雪卡鱼毒风险的影响，我们利用已发表的数据，对澳大利亚 Platypus 湾海洋食物链的四个营养级中的雪卡毒素转移进行了建模。支持首次尝试对每个营养级转移步骤的规模进行概念化的数据非常有限，导致了广泛的估计。我们所探索的假设情况产生了一条低毒性的 10 公斤西班牙鲭鱼（），其鱼肉中的雪卡毒素-1（P-CTX-1，也称为 CTX1B）浓度为 0.1µg/kg，这是由海洋食物链中 12-4900 万枚底栖甲藻（ sp.）产生的 19.5-78.1µg P-CTX-1 当量（eq.）所产生，这些甲藻每细胞产生 1.6×10 g 的 P-CTX-1 前体 P-CTX-4B。这些西班牙鲭鱼可能会附着在 Platypus 湾大部分底部覆盖的底栖大型藻类（）上，重达 22-88 公斤，毒素转移到估计有 40000-160000 只第二营养级的滨蟹（）中。这个庞大的滨蟹数量似乎不切实际，但有毒的滨蟹很可能会被一群小型、有斑点的镖鲈（）吃掉，这会减少每条鱼所消耗的滨蟹数量。西班牙鲭鱼通过捕食这群斑点镖鲈并食用 3.6-14.4µg 的 P-CTX-1 eq.，会在鱼肉中积累 0.1µg/kg P-CTX-1 eq.的浓度。然而，已发表的数据表明，这种毒素负担可能会被一条 10 公斤重的西班牙鲭鱼从仅仅一到三条斑点镖鲈身上积累，这表明在某些时候，必须通过 Platypus 湾食物链产生和转移比这里建模更多的毒素。该模型突出表明，需要更好地定量估计海洋食物链中的雪卡毒素产生、生物转化和清除，以提高我们对雪卡鱼毒风险的理解和管理。
