Intra-tissue distribution of tetrodotoxin in two marine puffers Takifugu vermicularis and Chelonodon patoca.

Micro distribution pattern of tetrodotoxin (TTX) in several tissues of marine puffers Takifugu vermicularis and Chelonodon patoca was investigated by means of monoclonal antibody-based immunoenzymatic technique under light microscope. In the investigation TTX was visualized at glands in the skin of T. vermicularis, while in C. patoca TTX was detected in succiform cells of the skin section. Similarly, in the ovary section of T. vermicularis TTX was recognized at late peri nucleolus stage, yolk granule stage-I, and yolk granule stage-II of oocytes. The oocytes of late peri nucleolus stage and yolk granule stage-I showed TTX antigen at their nucleus and yolk vesicles, while in yolk granule stage-II TTX was visualized at yolk granules and yolk vesicles. In the ovary of C. patoca TTX was detected in the connective tissues and in the nucleus of some perinucleolar oocytes. In the liver and muscle of C. patoca TTX was found to be distributed in parenchymal hepatocytes and muscle fiber, respectively. This study, however, reveals that intra-tissue distribution of TTX varies in respect of species.