speculate on the possible interrelationship between the
toxins of cyanobacteria (Schizothrix), giant clams (Tridacna),
and ciguateric fish. Following the observation by the Gilbertese
on Marakei (Gilbert Islands, Republic of Kiribati) of
the simultaneous appearance of toxic fish and cyanobacteria
(Schizothrix calcicola), Banner (1967) subjected these
cyanobacteria to chemical analysis and isolated two toxic
substances, one soluble in water, the other one in organic
solvents.