Seasonal distribution of Tetrodotoxin and analogues in trumpet shell Charonia lampas (Linnaeus, 1758)

Abstract

Tetrodotoxin (TTX) is a potent neurotoxin, first identified in a fish from the Tetraodontidae family. The first and only known case of human intoxication in the European Union (EU) occurred in Spain in 2007, following the consumption of a trumpet shell, Charonia lampas. In response to this incident and subsequent studies identifying TTX in bivalves and marine gastropods within the EU, the European Food Safety Authority (EFSA) recommended a safety limit of 0.04 mg TTX eq/kg. However, no regulation has yet been established in the EU. This study aims to evaluate the temporal variability of TTX and its analogues in trumpet shells and their primary prey, the starfish species Astropecten aranciacus. A total of 25 individuals from each species were captured between November 2021 and October 2022. The results indicated high concentrations of TTX and its analogues in the non-edible tissues of trumpet shells, exceeding the EFSA’s recommended limit. In edible tissues, only the analogues dideoxyTTX3 and trideoxyTTX3 were present at quantifiable levels. For starfish tissues, nine samples surpassed the EFSA’s recommended limit. These findings align with existing literature, which reports higher toxicity in non-edible tissues and organisms from higher trophic levels, supporting the theory of TTX bioaccumulation. No statistically significant temporal variability of TTX was observed, implying that the time of year does not influence TTX accumulation in the studied species. These results support the need for implementing TTX monitoring programs in Europe and increasing public awareness to prevent intoxication episodes.