Cylindrospermopsis raciborskii mild skin reactions upon exposure. The last two toxins, anatoxin-a and saxitoxin, are thought to be shellfish neurotoxins. Research has shown that "C. raciborskii" can naturally produce butylated hydroxytoluene, an antioxidant, food additive, and industrial chemical. Domain – Bacteria The Tree of Life contains three Domains: Bacteria, Archaea, and Eukarya. Kingdom – Bacteria Bacteria consists of prokaryotic microorganisms. They were among the first life forms to appear on Earth and appear in a wide variety of habitats. Phylum – Cyanobacteria This phylum is characterized by their ability to obtain energy through photosynthesis. They are often called the blue-green algae stemming
Algae included in Protista, later also abandoned in favour of Eukaryota. However, as a legacy of the older plant life scheme, some groups that were also treated as protozoans in the past still have duplicated classifications (see ambiregnal protists). Some parasitic algae (e.g., the green algae "Prototheca" and "Helicosporidium", parasites of metazoans, or "Cephaleuros", parasites of plants) were originally classified as fungi, sporozoans, or protistans of "incertae sedis", while others (e.g., the green algae "Phyllosiphon" and "Rhodochytrium", parasites of plants, or the red algae "Pterocladiophila" and "Gelidiocolax mammillatus", parasites of other red algae, or the dinoflagellates "Oodinium", parasites of fish) had