Protists

Protists are a kingdom that is sort of a dumping ground for organisms that don’t fit the descriptions of the plant, animal, or fungi kingdoms. Many are single-celled but eukaryotic, but many diverse forms exist. Some examples of protists include amoeba, euglena, slime mold, diatom, paramecium, dinoflagellate, macroalgae, etc. From the examples I listed, some have more than one cell and can be complex, or have other non-traditional features. Dinoflagellates in particular are behind the red tide in Florida.

Some protists can cause disease through vectors like

  • Plasmodium, which causes malaria via mosquitoes,

  • Trypanosoma, which causes sleeping sickness via tsetse flies,

  • Giardia, which causes giardiasis via beavers

  • Entomeoba histolutica, which causes leishmania via sandflies

Interesting protists

Stentors are trumpet/funnel-shaped, attach to things, and contract when disturbed.

Amoebas are unique in that they can catch their food and shape themselves around it like a mouth opening.

Paramecia are unique in that they have lots of cilia to move around and can pass food to their “mouths”

Trichonympha have a mutualistic relationship with termites and live in the termite gut.

Nassulas eat cyanobacteria filaments like spaghetti.

Algae is interesting because it is an autotroph that does photosynthesis, like a plant. There are many types of algae, green ones like nitella (not Nutella). Some, like the volvox, form colonies. Many are like plants, but many types of algae aren’t.

One type of algae, chera, can be found in Wisconsin and has many ecological properties for lakes because it can clean up water, and growing to 12 to 18 inches, it can’t easily be chopped up by a boat’s outboard motor like other plants. Waterfowl can eat it, and when washed up on shore, it smells bad enough to be named “musk grass.” Despite all these things, It’s still a protist.

Brown algae have gelatinous properties that can be harvested for cosmetics and agar, which is a scientific product for growing microorganisms.

Pigment is toxic to humans and causes red tide. If filter-feeders, like clams, eat enough of it, and a human eats the clam, the toxins are passed to the human.

Red algae is found in deep water and is also very plant-like.