View a gracefully swimming microbe called Bursaria truncatella. This is the largest of the protists and can be easily spotted with the naked eye. It has a large mouth shaped like a scoop and will eat other microbes of almost any size.
A common pond water inhabitant, Euplotes has cilia (hair-like projections) that are different from many other microbes. Here, bundles of cilia are fused together into thick bristles used for food gathering and locomotion. Sometimes Euplotes looks like a crab scuttling around on the slide. Other times it swims through the water.
Spirostomum demonstrates that microbes can come in any shape and size. It glides through the water by beating hair-like cilia on its surface. Spirostomum feeds on microbes through a round oral groove at one end of its body.
At this exhibit visitors observe a slipper-shaped, single-celled organism called Paramecium caudatum. Paramecium is one of the best known microbes. It moves swiftly and gracefully through the water by the coordinated beating of its cilia (hair-like projections). Along one of its sides, Paramecium caudatum has a depression called an oral groove. Food, primarily bacteria, is forced into this groove by the water flow created by the beating of the cilia in the oral groove. Dark spots visible in the center of the paramecium are food vacuoles. Food vacuoles are bubble-like containers that surround food caught by microbes. Inside the vacuoles food is digested by enzymes.
Dileptus is rather large for a protozoan. It probes its environment with a long, flexible, snout-like structure, reminiscent of an elephant's trunk that is simply an extension of its cell membrane. It uses this "proboscis" to capture smaller protists and stuff them into its mouth, located at the base of the trunk-like structure. This single-celled microbe has cilia (hair-like projections) surrounding its body which it uses to swim. Also visible with Dileptus are algae and other microbes it may have eaten. Dark spots inside its body are the things it has recently eaten.
Paramecium bursaria, a singe-celled green microbe, is not an algae; however it does have many algae, called Chlorella, living inside of it. This is an example of mutualistic symbiosis; both partners gain some advantage from the close association. The paramecium obtains necessary nutrients from the products given off by the Chlorella. In exchange, Paramecium bursaria provides protection and increases mobility for the chlorella.
Look for a gray unequally shaped microbe with a lot of small dots inside. To eat, the amoeba flows around its food, like a fog surrounding a skyscraper engulfing it.
The unusual looking microbe at this exhibit is actually a colony of single algae cells called Volvox. Each of the dots seen in the outer sphere is a single cell. Inside this main colony, daughter colonies in the form of smaller green balls can be seen. Eventually the outer sphere bursts and the daughter colonies are set free. Volvox rolls through the water propelled by beating two whip-like projections called flagella.
Stentor is a protozoan shaped like a trumpet with cilia (hair-like projections) around its large mouth. The cilia sweep small particles of food, such as bacteria and algae, into its mouth. You have to look very closely to see the waving cilia. Stentor has a long flexible stalk that it uses to attach itself in position. Although this is the characteristic shape of the microbe, Stentor can also swim freely. When the stalk is retracted the Stentor looks rounder.
Blepharisma, whose root word “Blephar” means eyelid in Greek, are microbes that are commonly found in ponds. If there are a lot of Blepharisma in a pond, the water in the pond will turn pink. When scientists first discovered these microbes, the long cilia near its mouth reminded them of eyelashes, coining the name Blepharisma.
Euglena, a green microbe that lives in ponds, swims by moving a single hair-like whip at the end of its body. Euglena contain chlorophyll and can even make their own food. An abundance of these microbes will cause the water to look green. Although the Euglena is one of the smallest microbes, it is still many times larger than bacteria.