Palytoxin is a highly toxic
natural product found in many (but not all) members of the genus
Palythoa. The substance was first isolated from the seaweed-like "
limu-make-o-Hana" ("Seaweed of Death from Hana") in 1971 in
Hawaii. Scientific investigation of the seaweed found it to be a colonial
cnidarian, which was classified as a
zoanthid and named
Palythoa toxica. The presence of this toxin is of significance to
aquarists who keep
reef aquariums, as
Palythoa and related zoanthids are commonly kept as display specimens in
marine aquaria. Aquarists have reported symptoms consistent with palytoxin poisoning prior to having exposure to zoanthids suspected to contain the toxin. One report involved an aquarist being accidentally poisoned through skin injuries after handling various zoanthids. Another report involved an aquarium hobbyist in Virginia who experienced a severe respiratory reaction after trying to eradicate colonies of a brown zoanthid (suspected to be
Palythoa) from rocks in their aquarium. A 2010 study found that a single specimen of
Palythoa from a sample of fifteen colonies purchased from three aquarium stores in the
Washington D.C. area contained high levels of palytoxin, indicating that toxic individuals are occasionally present in the captive population. While poisoning events have occurred, they are exceedingly rare, and many reef hobbyists have kept
Palythoa without any adverse reactions. It is generally recommended to always wear appropriate protective gloves and goggles when maintaining aquaria. ==Taxonomy and systematics==