Hàm lượng độc tố tetrodotoxin (TTX) của cá nóc theo loài, giới tính và theo vùng biển

Abstract

Pufferfish belong to the order Tetraodontiformes and contain Tetrodotoxin (TTX). Pufferfish have long been regarded as a favourite dish in many countries in the worlds, especially in Asia, such as Japan, South Korea, China, Vietnam, etc. and puffer fish poisoning have been recognized since long ago. In recent years, the trend of using pufferfish for food has been increasing and pufferfish poisoning occurs more commonly. In Vietnam’s seawater, 41 pufferfish species have been identified, of which 21 species containing TTX have been found. Using the mouse bioassay, this study analyzed TTX content in 11 species of pufferfish with a total 315 specimens collected on fishing vessels and bought at fish landing ports from the North to the South. The results showed the average content of TTX in pufferfish of 86.84 MU/g, of which the highest TTX content (284.07 MU/g) in Arothron immaculatus and the lowest level (1.42 MU/g) in Lagocephalus spadiceus. Applying the Two Sample Assuming Unequal Variances test to compare the content of TTX in male and female pufferfish showed that in general, female individuals had much higher TTX levels than males, this difference was statistically significant with the 95% confidence level. However, when analyzing each species in detail, the significant difference was only realized in three species of Arothron immaculatus, Lagocephalus lunaris and Torquigener pallimaculatus. Using the ANOVA single factor to compare the TTX content in pufferfish collected in 3 key seawater areas of Vietnam indicated that TTX content of pufferfish in the Central area was at 114.86 MU/g, much higher than in the South (72.21 MU/g), the Gulf of Tonkin (average 18.87 MU/g). This difference is statistically significant at a 95% confidence level.