Chromista—ever heard of them?
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Chromista—ever heard of them?
There are seven kingdoms of life (living beings):
1. archaea (fka archaebacteria)
2. bacteria
3. protozoa ("protoanimals": eukaryotic unicellular microorganisms)
4. fungi
5. plants
6. animals
…and…surprise!…
7. chromista
What is a chromiston (chromistum?)?
It's an organism which belongs to a newly acknowledged kingdom of organisms.
The term "chromiston/-a" means "colored" (Greek "chroma" = "color"); but it mustn't be taken too literally, because there are both uncolored chromista and colored non-chromista.
"Chromista n. a proposed taxonomic kingdom containing the Hyphochytriomycota, Labyrinthulomycota, Oomycota (water moulds), Phaeophyta (brown algae), Chrysophyta (golden algae), Bacillariophyta (diatoms), Haptophyta (coccolithophorids) and Xanthophyta (yellow-green algae). A very similar grouping has also been given the name 'Stramenopila'."
(Henderson's Dictionary of Biology, 16th ed., edited by Eleanor Lawrence. Harlow, UK: Pearson, 2016. p. 107)
What is confusing is that not all algae are chromista. For example, green algae and red algae aren't, because they are plants—as opposed to e.g. brown algae such as kelps, which are chromista.
As for all seven kingdoms of life, see this authoritative paper:
A Higher Level Classification of All Living Organisms
Here's another authoritative paper by the biologist who coined the term "chromista", Thomas Cavalier-Smith:
Kingdom Chromista and its eight phyla
QUOTE>
"Chromista is one of five eukaryotic kingdoms recognised in a comprehensive seven-kingdom classification of life (Ruggiero et al. 2015). As here critically reassessed, Chromista comprise eight distinctive phyla, not just three as in the first substantial systematic treatment 30 years ago (Cavalier-Smith 1986)—5 years after Chromista was established (Cavalier-Smith 1981a). Chromista have turned out to include the vast majority of marine algae and of heterotrophic protists, whether marine or in soil or freshwater, and some of the most serious human disease agents such as malaria parasites and agricultural pathogens like potato blight and sugar beet rhizomania disease, making chromists immensely important for ocean ecology, soil biology, climate stability, agriculture, and medicine, as well as for fundamental understanding of eukaryote evolution and biodiversity. They have a greater range in radically different body plans and lifestyles than the entire plant kingdom and more phyla than kingdoms Fungi or Protozoa. Only animals and bacteria have more phyla than chromists, but even they cannot match chromists in their remarkable range of contrasting adaptive zones—from giant brown algal kelps longer than a blue whale to ciliates like Paramecium, dinoflagellates that power coral reefs or kill shellfish, the most abundant predators in soil (sarcomonad Cercozoa), parasites like Toxoplasma whose cysts are allegedly lodged in a third of human brains and Plasmodium that causes malaria, diatoms whose silica frustules were once essential for making dynamite or polishing astronomical telescope mirrors, and foraminifera or haptophyte plankton like Emiliania that can be seen from outer space and made the white cliffs of Dover with their calcareous scales and are probably the most speciose photosynthetic oceanic flagellates and exude volatile chemicals that affect cloud formation and global energy balance.
There are probably in excess of 150,000 free-living chromist species, the most speciose being diatoms (estimated at ~100,000 species) and foraminifera (~10,000 living and ~ 40,000 fossil species), many thousands undescribed. Parasitic chromists could be ten times that, as chromist Sporozoa probably infect every insect and every other animal species, and other chromists to infect numerous plants, and even some protozoa or other chromists. Already named chromist species (over 180,000; Corliss 2000) may be only the tip of the iceberg. There are probably far more species of chromist than of plants or protozoa, conceivably even more than fungi, and certainly more individual chromists than plants and animals combined. Possibly, only viruses and bacteria exceed them in numbers."
<QUOTE
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Re: Chromista—ever heard of them?
It may seem hard to believe that microscopic diatoms, with their delicate silica skeletons only forty millionths of a meter long, can be related to the giant kelps, which may grow as long as fifty meters, or that either one is related to the downy mildew that nearly destroyed the French wine industry. But they are related – placed together in the great kingdom-level taxon Chromista.…"
Source: https://ucmp.berkeley.edu/chromista/chromista.html
Here you can see a kelp forest:
- Consul
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Re: Chromista—ever heard of them?
- Consul
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- Joined: February 21st, 2014, 6:32 am
- Location: Germany
Re: Chromista—ever heard of them?
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