Ostracitoxin – a Potent Natural Fish Poison

Ichthyocrinotoxic fishes are those which produce their own toxins through glandular secretions without any venom apparatus. Sixty species of fishes under eighteen families fall in this category among which the family Ostracidae is one. Ostracidae is a family of squared, box shaped fishes very much related to the puffers and filefishes under the order Tetraodontiformes. Skin mucous secretions of the members of family Ostracidae are found to possess a potent ichthyocide known as Ostracitoxin. The toxin is also known as Pahutoxin. Suspected to be produced by the club cells of the epidermis of boxfishes, Ostracitoxin is secreted only when the boxfishes are under stress. The toxin is found to possess various effects on the biological systems. The notable among them are its toxicity to various marine organisms and hemolytic activities. Chemically, the toxin is a choline chloride ester of 3-acetoxy palmitic acid which is relatively similar to red tides and sea cucumber toxins in its basic properties. RP-HPLC separation of the crude toxin yields an ichthyotoxic protein fraction termed “Boxin”. This review summarizes the origin of the ostracitoxin, its toxicity characteristics, properties, mode of action and poisoning effects.