Tetrodotoxin in Invasive Silver-cheeked Toadfish Lagocephalus sceleratus (Gmelin, 1789) in the Adriatic Sea

Abstract

It is commonly thought that toxic compounds come only from anthropogenic sources; however, toxic compounds can be of natural origin; hence, we call them natural toxins. In the marine environment, some molluscs and crabs contain natural toxins produced by symbiotic bacteria. Shellfish in addition to the accumulation of natural toxins (biotoxins) may produce toxic secondary metabolites. Some species of phytoplankton are known to produce potent natural toxins, which is also the case with some species of fish, especially pufferfish. The main feature of such toxins is thermostability, meaning they do not get destroyed through thermal food processing at any temperature and their toxicity remains unchanged. Here are presented the results of tetrodotoxin investigations in silver-cheeked toadfish Lagocephalus sceleratus (Gmelin, 1789) from the Adriatic Sea. It is a poisonous marine pufferfish that has reached the Mediterranean from the Red Sea through the Suez Canal (Lessepsian migration). Owing to its exceptional biological features such as rapid growth, high reproduction potential and lack of natural predators, it soon established large self-sustainable populations mostly in the Eastern Mediterranean Sea. This species has also been recorded in the Adriatic Sea; however, its presence is still of periodic nature, and currently there is no evidence which would suggest permanent population establishment. Tetrodotoxin is a very potent toxin that has been detected in organs such as the skin, muscle, liver and gonads of the pufferfish specimens collected in the Adriatic Sea.