Pond Scum Under the Microscope - Pondlife Ep 1
Pond Scum Under the Microscope – PONDLIFE, Episode 1
[ELECTRONIC MUSIC]
[American Museum of Natural History logo animates on and off over footage of pond grasses fluttering in the wind.]
[Animation of hand dipping a sample cup into water.]
[Animation of a pipette putting a drop of water onto the slide of a portable microscope.]
[ELECTRONIC MUSIC AND SOUND OF WATER DROPLET]
[Animated view through a microscope’s eyepiece. The title “PONDLIFE” resolves into view, surrounded by microscopic organisms.]
[MICROSCOPE SLIDE CLICKS INTO PLACE]
[Dr. Sally Warring walks down the front steps of the American Museum of Natural History.]
[BOUNCY, ELECTRONIC MUSIC]
[Scenes of Warring walking down New York City streets segue into views of Central Park nature.]
SALLY WARRING (microbiologist): My name is Sally. I am a biologist at the American Museum of Natural History where I study microscopic organisms.
[Warring draws a sample from the Harlem Meer—a pond in Central Park—and other water bodies. New Yorkers and tourists enjoy the Park around her.]
WARRING: On Pondlife we are going to go on a safari to explore the microbial wildernesses that exist all around us.
[Views of Central Park’s Harlem Meer—a manmade pond, surrounded by trees, with buildings towering in the distance.]
WARRING: I’m in the middle of Manhattan.
[Warring speaks to camera, standing next to the Harlem Meer.]
WARRING: I’m at the Harlem Meer in Central Park and I’m here to look for a particular microbial community.
[Pond scum floats on the surface of the Harlem Meer.]
WARRING: It’s a community that you might have seen before, but you’ve probably not looked at it quite like this.
[Grasses and reeds grow on the edges of the Meer. Ducks paddle in the water.]
WARRING: For most of human history, people thought of all life as being plants and animals.
[Warring speaks to camera.]
WARRING: And the fact that species existed that were so small that you couldn’t even see them…
[Close-up of pond scum floating on the surface of the Meer.]
WARRING: …was completely unknown.
[Warring speaks to camera.]
WARRING: That all changed in the Seventeenth Century when a Dutch fabric designer…
[Portrait of a man with shoulder-length curly wig and neck scarf. Text labels him as “Antonie van Leeuwenhoek.”]
WARRING: …named Antonie van Leeuwenhoek invented the most powerful microscope the world had ever seen.
[Warring speaks to camera and pulls a small microscope out of her back pocket.]
WARRING: I have a replica of his microscope in my pocket. This is it.
[Close-up of a small piece of metal with various attachments, mounted on a rod.]
WARRING: This tiny little thing contains a really small spherical glass lens…
[Warring speaks to camera, holding the mini-microscope.]
WARRING: …and that spherical glass lens was capable of magnifying up to 300 times.
So, he would place he was interested in on one side of the lens. He would look through by placing the microscope right up to his eye.
[Warring holds the mini-microscope up to her eye. She then speaks to camera.]
WARRING: So, using this microscope he became the first person to see unicellular life, and he first saw that unicellular life when he looked at a community of microorganisms called pond scum.
[Close up of lumpy pond scum, floating on the surface of the Meer. Warring speaks to camera.]
WARRING: And I can see a beautiful example right over here.
[BUBBLY ELECTRONIC MUSIC]
[Warring walks over to side of the Meer and kneels down next to the water.]
WARRING: This is great…
[Using a stick, Warring pulls out a stringy, slimy mass of material from the floating pond scum.]
WARRING: This is exactly what we’re looking for.
Beautiful pond scum.
[Warring puts the pond scum into a sample jar. She holds the jar up for the camera.]
WARRING: Success!
[Warring sits on a park bench, holding the Leeuwenhoeck replica microscope.]
WARRING: That pond scum is a growth of filamentous green algae and I’ve put some here on my Leeuwenhoeck microscope…
[Extreme close-up of a strand of algae mounted on the mini-microscope.]
WARRING: …and we’re going to take a look and see what he might have seen in the pond for the first time.
[Warring speaks to camera from the park bench. She raises the Leeuwenhoeck microscope to her eye.]
[A view of dozens of green, thread-like strands resolve into focus, although the image is somewhat cloudy.]
WARRING: Leeuwenhoeck learned by looking through his microscope that the pond scum was made up of green algae that wound together.
[Small organisms move among the green strands.]
WARRING: But what amazed him the most was that moving amongst that green algae were tiny little creatures.
[Illustration of microorganisms in various forms—some resemble jellyfish or a broom.
WARRING: He called those little creatures animalcules or “little animals.”
[Warring speaks to camera from the park bench. She holds a modern portable field microscope.]
WARRING: These days microscopy and our understanding of microbiology have come along way. I have with me a modern-day field microscope. Rather than a small spherical lens it has an objective.
[In close-up, Warring holds the field microscope. Off to the side is an animated diagram of the lens objective. It’s cylindrical in shape.]
WARRING: An objective contains many glass lenses stacked one on top of the other.
[The lens objective housing dissolves into an illustration of the stacked lenses, which then telescope apart to illustrate their various shapes and sizes. Some are thicker, some with more extreme convex sides, one somewhat mushroom-shaped.]
WARRING: We’re gonna take a look at what we’ve got.
[Warring places a glass slide on the field microscope, and with a pipette, drops on a sample from the Meer. She clamps the slide into place and then peers through the lens.]
WARRING: At one hundred times magnification we can really see the details of the green algae.
[The green algae appears as thick, rope-like strands under the microscope.]
WARRING: It’s called spirogyra.
[ELECTRONIC MUSIC]
WARRING: Each spirogyra filament is one cell thick, about the width of a human hair.
[In various views of the spirogyra, the strands have clear walls, inside of which are coiled, thinner filaments. This is clearly seen in an extreme close-up where the coil looks like a tight spring.]
WARRING: Spirogyra gets its name because inside each cell there is a long, thin, green chloroplast that coils and gives the organism its corkscrew appearance.
[An animated graphic indicates the green coil as a “chloroplast.”]
WARRING: Spirogyra, like all algae, live off sunlight.
[Strands of spirogyra slide slowly across the microscope’s field of view.]
WARRING: But when they grow in dense mats like the one in the Harlem Meer the filaments on top end up shading the ones beneath.
But Spirogyra has a way of dealing with this. The filaments are able to glide and stay constantly on the move. This way each filament will, at least for part of the time, have access to the sun.
[A small organism darts among the strands of spirogyra.]
WARRING: Just like Leeuwenhoek we find many microbial creatures living among the algae.
[A close-up of an elliptical microscopic organism. Animated text names it as a “ciliate.”]
WARRING: Here there are several species of ciliate.
[A different, circular-shaped ciliate is shown. Hundreds of tiny hair-like threads ring the ciliate and move swiftly, propelling the organism in a counterclockwise rotation.]
WARRING: Ciliates are a diverse group of single cellular organisms that are covered in small, hair-like structures called cilia.
[An animated graphic indicates the external hair-like structures and the text “cilia” appears.]
WARRING: Each species of ciliate has a unique arrangement of cilia.
[Small semi-circular organisms travel along the side of a spirogyra strand, as if they are moving up and down a road.]
WARRING: This one has cilia only on the underside of its cell. It uses the cilia like tiny legs to walk about on the spirogyra.
[FLUTTERING ELECTRONIC MUSIC]
[Bell-shaped organisms tremble at the end of long, slender stalks.]
WARRING: This is one of the ciliates that Leeuwenhoek was first to describe. It’s called Vorticella. Each is an individual bell-shaped cell sitting atop a long stalk.
[Close-up of the bell-shaped parts of several Vorticella. Wider view of several Vorticella near a few strands of spirogyra.]
WARRING: That stalk is rather special. It’s a curious coiling contraption that can move like lightning if the cell senses any danger.
[The Vorticella contract at a remarkable speed and then return to the full length of their stalks.]
[ELECTRONIC PULSES]
[Close-up of the bell-shaped part of one Vorticella.]
WARRING: The stalk also keeps the Vorticella anchored, so that it can use its cilia to generate a current in the water.
[Around the lip of the “bell,” numerous thin cilia move rapidly.]
WARRING: The cilia are arranged in a ring around an opening in the cell that acts as a mouth.
The cilia beat and drag water, bacteria, and other small microbes right into the Vorticella’s waiting mouth.
[A transparent circular organism with radiating spine-like structures sits among threads of spirogyra.]
WARRING: This beautiful organism is a heliozoan—“helio-“ meaning sun and “-zoan” meaning animal. Though, it’s not an animal at all.
[Close up of a heliozoan. A graphic points out the “spines,” and names them as “axopodia.”]
WARRING: The heliozoan is covered in many spike-like structures called axopodia, which radiate out from the cell’s surface and act as a net for ensnaring prey.
In real time the heliozoan appears static, but in time lapse it really comes to life.
[CYCLING ELECTRONIC MUSIC]
[The heliozoan moves among the spirogyra in sped-up footage, using its axopodia to propel it through the spirogyra. It engulfs a much smaller organism.]
WARRING: A green cell is ensnared…
[An animated graphic indicates the small organism trapped inside the heliozoan and text reads, “a catch!”]
WARRING: …but makes a lucky escape.
[The small organism escapes the clutches of the heliozoan. A second, greenish organism is now ensnared by the heliozoan.]
WARRING: The second cell is not so lucky.
[An animated graphic indicates the small green organism and text reads, “dinner!”]
[A leaf-shaped organism swims by, like a manta ray twisting in spirals. Text identifies it as a Phacus.]
WARRING: Leeuwenhoek was fascinated by organisms that moved like animals, but were green like plants.
This one is called Phacus. It’s not an animal, or a plant. It belongs to a completely separate group of organisms called the euglena. Its movement is due to long, thin structure called a flagellum that extends out the front of the cell.
[An animated graphic points out the flagellum waving rapidly back and forth at the “front” of the euglena.]
WARRING: The flagellum beats and pulls the cell through the water. You can also catch a glimpse of a red spot inside the Phacus. This is called an eyespot.
[Animated graphic indicates the red eyespot as the Phacus moves through the water.]
WARRING: It sits at the base of the flagellum and can detect the intensity and direction of light.
[The Phacus swims between the much larger strands of spirogyra.]
WARRING: Like a plant the Phacus lives off sunlight and this eyespot allows it to move through the water to wherever the light intensity is best.
[LILTING ELECTRONIC WALTZ]
[On the park bench, Warring removes the microscope from her eye and speaks to camera.]
WARRING: In that one drop of water we just saw a wide variety of microbial species. In the whole pond their numbers probably reach into the many thousands. And that’s only scratching the surface of the amount of microbial diversity that we could find the world over. And to really get a handle on this microbial diversity, we’re just going to have to keep exploring.
I’m gonna put these microbes back where I got ‘em from.
[Warring takes the sample jar back over to the Meer and puts its contents back in the water. She picks up her bag and walks off.]
[Text reads, “This series was made possible with a grant from Science Sandbox, an initiative of the Simons Foundation, and with the support of the Gordon and Betty Moore Foundation.”]
[Credits roll over various scenes of the Harlem Meer and its surroundings.]
Pondlife follows Museum microbiologist Sally Warring on a safari exploring the microbial wilderness all around us. In this episode we dive into a drop of pond water to discover the surprisingly beautiful world of pond scum.
Watch other episodes from the Pondlife series:
This series was made possible with a grant from Science Sandbox, an initiative of the Simons Foundation, and with the support of the Gordon and Betty Moore Foundation.