Brief comment: it seems to me that an article like this could benefit greatly, for the benefit of people who don't actually know what protista are and therefore need this article, to begin with examples of protists. Whenever defining any term in any field, it always helps to begin with concrete examples (if possible). Generally speaking, unless you're just trying sum up the knowledge of biologists, without good examples generously interspersed, and other jargon explained, these articles aren't going to be as helpful as they might otherwise be. --LMS
Ok. What protists are people familiar with that reference can be made to? The only ones I can think of that are truly well-known are Amoeba - maybe Paramecium and Euglena, but I'd be surprised if anyone has heard of those and didn't know they were protozoa. Multicellular forms people would know, but they're already mentioned on the page. Maybe it would help to say the rest comprise all single-celled forms, instead of are just single-celled? --JG
You'd know the answer to your questions better than I would, I'm sure. When I write an article or lecture about a philosophical subject to nonphilosophers, I try to ease my way into the subject, if I can. That's all. --LMS
The term seaweed covers a large array of lifeforms, some of which are in the plantate (plant) kingdom, and some of which are in other kingdoms, specifically protista. Are all commonly eaten seaweeds in the plante kingdom? Are there any protista seaweeds (or any protista anything) which are eaten? RK
Perhaps we can add some sort of breakdown of the Protista "kingdom" like this?
There are many Eukaryote Kingdoms, including Plantae, Fungi and Animalia. The rest of the many eukarote kingdoms are, for the sake of convenience, lumped together into a super-kingdom known as "protista". However, DNA and RNA analysis of these lifeforms shows that the protista actually consist of many kingdoms, each as distinct from each other as plantae is from fungi or animalis. The precise terminology and method dividing these kingdoms is still undergoing many changes, and the terms below are not accepted by all authorities.
Diplomonads - Only a very small number of organisms are in this category.
Microsporida - These all live as parasites inside the cells of their hosts. They reproduce by sudden bursts of division to generate an instan swarm.
Parabasalids - Only a small number of organisms are in this category.
Myxomycota - True slime molds. They form patches of wet slime on fallen, rotting logs.
Euglenozoa - Single-cellular organisms that can move by waving a flagellum. Some have chloroplasts and engage in photosynthesis, while others do not.
Naegleria - They live as amoebas in dirty water, feeding on bacteria. They can develop flagella and swim.
Entamoeba - A kingdom with many kinds of parasitic amoebae. Some species in this kingdom live in the human colon.
Acrasiomycota - Cellular slime molds. They live in fresh water, on damp soil, or on rotting logs and vegetation.
Rhodophyta - Red seaweeds; these are not in the plant kingdom! About 400 species are known.
Alveoles - Contains three taxa (large categories): ciliates, dinoflagellates and apicomplexans.
- Ciliates - These have cilia all over their surface, and most have more than one nucleus. They live in both fresh and sea-water, and feed on bacteria.
- Dinoflagellates - Marine plankton that mainly live in salt-water. They are propelled by a single flagellum. Most live as single cells, while some species will form colonies. A few species have chlorophyll and undergo photosynthesis.
- Apicomplexa - These are all parasites of animals that can reproduce in bursts by producing a host of spores.
Stramenophiles - A group of six related protist kingdoms:
- Labyrinthulids - better known as marine slime nets. They form transparent colonies that live on seaweed. They secrete mucus and actin-like proteins, creating a trail that they then travel along.
- Oomycota - While not a true fungus- these are fungus-like protists. Some species in this kingdom include water moulds, white rusts and down mildews. They digest their food by secreting enzymes and absorbing he dissolved nutrients. They live off of dead, decaying material, or as parasites. The most infamous member of this kingdom is potato blight, which caused the Irish famine during the 1840s.
- Xanthophyta - Yellow green cells that can form colonies in fresh water. Only a hundred species in this kingdom are known.
- Chrysophyta - Golden algae, that live in fresh or salt water. Some are single-celled, some form colonies. The ones in salt water form beautiful silicon shells.
- Phaeophyta - Brown seaweeds; these are not in the plant kingdom! About 1500 species are known. All live in salt water. The most famous form is giant kelp, which can grow up to 100 meters (about 300 feet) long.
- Diatoms - A kingdom with about 10,000 species of marine plankton. They are surrounded by hard shells. They can live as single cells or form colonies. Most can photosynthesize.
Source: “The Variety of Life: A survey and a celebration of all the creatures that have ever lived” Colin Tudge, Oxford University Press, 2000