Common two-banded seabream (Diplodus vulgaris) as carrier of CTX in the Canary Islands

Abstract

Ciguatera fish poisoning (CFP) is a food poisoning for human, which usually produces digestive, cardiovascular and neurological signs. The toxin is produced by dinoflagellates of the genus Gambierdiscus and Fukuyoa, and it is bioaccumulated through the trophic chain of marine organisms. It is an endemic disease of tropical and subtropical areas originally but, recently, has also been discovered in temperate zones of the Atlantic. Other factors such as the international fish trade and international travel contribute to the spread of the disease, currently considering it as worldwide distribution. In the Canary Islands, an Official Control Protocol has been implemented since 2011 to study the dynamics of the disease and prevent the presence of fish with ciguatoxin for human consumption. In the present work, 30 samples of muscle of seifías (Diplodus vulgaris) caught in the Canary Islands were analysed within the framework of the Eurocigua project, financed by EFSA. The analysis method used was the cellular bioassay (CBA) with Neuro-2a cells to reveal CTX-like toxicity. Results obtained were semiquantified, considering low and medium toxicity of each sample. Positive samples were confirmed by LC-MS / MS as CTX toxicity and quantified. 42% (n=11) of the samples investigated showed CTX-like toxicity. 63% (n=7) of the samples were confirmed by LC-MS/MS, as CTX with a ppb range between 0.02 to 0.07 ppb. For positive samples, a statistically significant relationship between weight/lenght and CTX-like toxicity (p=0.005 and p=0.018, respectively) was also found. This work has found El Hierro island with the highest percentage of positive to CTX-like toxicity Diplodus vulgaris (64%) (n=9) fished in the Canary Islands