Toxin
When disrupted the cannonball secretes a mucus out of its nematocyst that contains a toxin. The toxin harms small fish in the immediate area, and drives away most predators, except for certain types of crabs. Although cannonballs do not commonly sting humans, it still has toxins which can cause cardiac problems in animals and humans. The toxin causes irregular heart rhythms and problems in the myocardial conduction pathways. Such complications are associated also with toxins of other coelenterates. The toxin is also harmful to the eyes, when the nematocyst comes in contact with eyes it is very painful and is followed with redness and swelling.
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