Migration of caulerpin from Caulerpa spp. to Sarpa salpa

Sarpa salpa is a fish species which is consumed in the Mediterranean Sea. It has been reported that S. salpa includes marine algae-based toxic molecules and this is why it shows neurotoxic and hallucinogenic effects on human. Invasive Caulerpa cylindracea and non-invasive Caulerpa prolifera are the most important members of Caulerpa genus in the Mediterranean Sea. Caulerpin is one of the secondary metabolites of this species which has important biological activities such as anti- tuberculosis, anti-proliferative and anti-nociceptive activity. On the other hand, this molecule has a detrimental effect on native fish species in the Mediterranean Sea. S. salpa is one of the fish species which consumes Caulerpa spp. In this study, caulerpin levels were investigated in Caulerpa spp and S. salpa tissues collected from İzmir coastlines in four seasons. Firstly, caulerpin was isolated from C. cylindracea and characterized by 1H-NMR, UV, MALDI-TOF/MS and melting point. The levels of caulerpin in the Caulerpa species and S. salpa tissues were analysed by RP-HPLC. Caulerpin was not detected in C. prolifera. While caulerpin levels in C. cylindracea and S. salpa tissues reached the highest value from the end of summer to the beginning of autumn, it decreased from the winter to spring. Finally, caulerpin was determined in the liver, brain and muscle tissues of S. salpa. It has been reported that S. salpa has negative effects on human health depending its Caulerpa-based diet. In this first study for Turkish coastlines, determination of caulerpin in S. salpa tissues is a proof for consuming of Caulerpa species by S. salpa. It is recommended not to consume S. salpa to avoid a possible health problem during the month August in which caulerpin concentration reached maximum level.