TOXINS FROM EGGS OF FISHES AND AMPHIBIA

The occurrence of poisonous eggs among fishes is reviewed. Authentic instances of poisoning can be attributed to eggs of fish from about 10 genera. The best known egg toxin, tetrodotoxin, from the eggs of puffer fish (order Tetraodontiformes) and newts (Salamandridae) is an aminoperhydroquinazoline compound (C11H17N3O8) of proven structure. It is extremely toxic (LD50=10 <g. per kg.) and blocks conduction in nerves by selectively preventing the increase in conductance to sodium ions that normally accompanies excitation. The eggs of the gar contain a toxin of high molecular weight that produces gastrointestinal symptoms in animals and is definitely not tetrodotoxin. The eggs of the marbled sculpin, or cabezon (Scorpaenichthys marmoratus), contain a toxin that inhibits growth of cells in tissue culture and produces necrosis in the liver and spleen. The toxin appears to be a protein or is attached to protein in the eggs. © 1969, American Chemical Society. All rights reserved.