60 THE ROLE OF ALGAE AND PLANKTON IN MEDICINE 



mouse on injection, while a few milligrams orally can be fatal to a human 

 being, especially when taken on an empty stomach. It has been estimated 

 that 4,000 algal organisms are required to produce human toxicity. The 

 shellfish store the poison chiefly in their "livers" or digestive organs; thus 

 the "dark meat" of the infested bivalves is much more toxic than the 

 "white" portions. The fish themselves are unaffected by the toxin, and 

 they will in fact excrete it in several weeks if Gonyaulax disappears from 

 the marine diet. 297 - 298 . 302 - 303 



Post-mortem examinations of animals and human beings who have died 

 of acute paralytic shellfish poisoning have, surprisingly enough, revealed 

 no structural changes. However, in chronically poisoned experimental 

 animals, distinct alterations are noted in the medullary ganglion cells and 

 in the large cells of the ventral horn of the spinal cord. 302 The Golgi 

 apparatus of small and medium-sized spinal ganglionic cells is also dam- 

 aged. Neural mitochondria remain normal, but those in the convoluted 

 tubules of the kidney show definite damage. In concert with the latter 

 finding are the clinical nephropathies reported by the French in human 

 shellfish poisoning. 304 ' 305 



It is probable that other algae besides Gonyaulax contain toxins. Some 

 have been associated with Ceratium and Prorocentrum, but no direct ex- 

 traction or isolation has yet been accomplished. It is also quite logical to 

 expect that fish other than mussels and clams could have improper plank- 

 tonic relations and thus transmit their toxins to predators. This is indeed 

 so, and — except for the puffer fish and possibly barracuda — it is likely that 

 poisonousness is directly dependent upon periodic ingestion of noxious 

 plankton, rather than being due to inherent toxicity. Planktogenic fish 

 toxicity can occur during any time of the year, while puffer and barracuda 

 may be most lethal during the reproductive season. Epidemics have been 

 unrelated to spoilage or bacterial infection. 



Poisonous fish are found through the world. They are most numerous 

 in the warm seas (especially in the Caribbean and Central and South 

 Pacific), but even certain arctic sharks have been reported to be toxic. Dur- 

 ing World War II, fish poisoning represented quite a problem, since 

 epidemics were encountered wherever American forces were stationed in 

 the Pacific theater. The Japanese, too, estimated that over 400 of their 

 military men died in Micronesia from eating toxic fish. Halstead and 

 Lively 300 have made a partial listing of fish most often found to be poison- 

 ous: surgeonfish, triggerfish, pompano, porcupine fish, wrasse, snapper, 

 filefish, surmullet or goatfish, moray eel, parrot fish, sea bass or grouper, 



