Jackson Estuarine Laboratory

Studies on Aphantoxin from Aphanizomenon Flos-Aquae in New Hampshire


Toxic Cyanobacteria (blue-green algae) bloom in eutrophic, freshwater lakes and ponds in New England and have caused environmental, health, legal and recreational problems over the past 15 years. Although several species have been implicated with animal kills and water fouling, a common offender was Aphanizomenon flos-aquae. Representative strains of A. flos-aquae bloom in New Hampshire intermittently, in both toxic (aphantoxins) and non-toxic forms. Research has focused on methods of: a) toxin accumulation from natural blooms and laboratory cultivation, b) toxin assay, using the mouse bioassay and a modified fluorometric technique developed for paralytic shellfish poisons, c) toxin characterization and purification, using solvent separation and molecular weight filters, and d) testing active extracts on nerve and muscle preparations to determine the specific sites and modes of action of aphantoxins.

Aphantoxin samples were passed through molecular weight filters (10,000 and 500 daltons), lyophilized and weighed, prior to physiological testing. Microgram quantities of toxin reversibly blocked compound action potentials in amphibian nerves as well as mechanical activity in skeletal muscle. No effect was measured on the transmembrane resting potential or on spontaneous miniature end-place potentials (mepps). Tests on lateral and medial giant s from crayfish gave similar salts. The Na+ dependence of the crayfish preparation was verified. The aphantoxins (4 μg/ml) reversibly blocked intracellular recordings of action potentials with no alteration of the resting potential. Amphibian and crustacean cardiac activity was blocked in diastolic arrest, while bivalve hearts were unaffected at increased dose levels. Aphantoxins may block excitability by affecting ion conductance pathways as do toxins from several marine dinoflagellates and may be useful in basic studies on membrane systems.


Jackson Estuarine Laboratory, Biological Sciences

Publication Date


Journal Title

The Water Environment: Algal Toxins and Health



Digital Object Identifier (DOI)


Document Type

Book Chapter


© 1981 Plenum Press, New York