Monthly Variation of Tetrodotoxin Levels in Pufferfish (Lagocephalus sceleratus) Caught from Antalya Bay, Mediterranean Sea

Abstract

The silver-cheeked toadfish (Lagocephalus sceleratus), an invasive alien pufferfish species that has rapidly settled throughout the Mediterranean region, poses significant threats not only to native marine species and fisheries but also to public health due to the tetrodotoxin (TTX) they harbor. In this study, TTX concentrations in L. sceleratus from Antalya Bay in the Northeastern Mediterranean Sea were investigated using Q-TOF-LC-MS on a monthly basis over a one-year period. Pufferfish were caught by angling from May 2018 to April 2019. The TTX levels in three different tissues (gonads, liver, and muscle) of 110 pufferfish in total were determined in both male and female individuals caught for 11 months. The highest TTX mean levels generally occurred in the gonads and the lowest in the muscle samples. As regards the maximum TTX contents, the highest concentrations determined were 68.2, 34.2, and 7.8 µg/g in the gonad, liver, and muscle tissues, respectively. The highest levels were generally observed in late autumn to winter (especially in November and December) in all tissues from both genders. Female individuals were generally found to be more toxic than male individuals. The TTX levels found confirm that the consumption of L. sceleratus from Antalya Bay remains dangerous throughout the year, and thus L. sceleratus constantly constitutes an important risk source for public health.

Automated Patch Clamp for the Detection of Tetrodotoxin in Pufferfish Samples

“…The TTX levels quantified in L. sceleratus tissues were in the range of those obtained in other studies: 0.05−58.44, 0.1−35.05, 0.09−1380.8, and 0.17−8248.51 mg TTX equiv./kg in muscle, skin, liver, and gonads, respectively [25]. The high TTX contents in the liver and/or gonads of pufferfish have already been observed in other works [12,25,[64][65][66][67][68]. Regarding the high TTX contents found in the liver, Anastasiou and co-workers suggested that it is related to hepatic uptake [66].…”

Assessment of Human Health Impacts from Invasive Pufferfish (Attacks, Poisonings and Fatalities) across the Eastern Mediterranean

“…The spawning season of L. sceleratus in the Mediterranean covers a wide period and can last from April to September [5,54,55]. The findings of studies on the toxin level of L. sceleratus in the Mediterranean Sea also show that L. sceleratus living in the Mediterranean Sea contain higher TTX in the late autumn months after the spawning period [15,31,34,56,57]. This is a phenomenon that may be specific to the Mediterranean ecosystem [31].…”

“…The findings of studies on the toxin level of L. sceleratus in the Mediterranean Sea also show that L. sceleratus living in the Mediterranean Sea contain higher TTX in the late autumn months after the spawning period [15,31,34,56,57]. This is a phenomenon that may be specific to the Mediterranean ecosystem [31]. The dangerous TTX is not destroyed by heating the fish meat or organs, and culinary chefs cannot simply remove TTX while preparing the fish.…”

“…The lethal dosage of pufferfish is categorized based on TTX amounts, with the safety threshold set by the Japanese authorities, at 10 MU/g TTX (equivalent to 2 mg TTX/kg) [30]. It must be emphasized that controversy surrounds acceptable TTX levels in seafood, particularly in the European Union [31]. The EU's lower limits contrast those of Japan (2.2 µg TTX eq/g) regarding shellfish and gastropods.…”

Another One Bites the Net: Assessing the Economic Impacts of Lagocephalus sceleratus on Small-Scale Fisheries in Greece

“…In contrast to the extensive research on the toxicity of the species in the Mediterranean Sea [34][35][36][37][38], quantitative assessments of its economic impact remain limited. Such assessments originate exclusively from the Mediterranean coasts of Turkey, where total losses due to L. sceleratus were estimated at around EUR 4.5 million per year [39,40].…”