MICROSCOPIC, or Close to It!
NO! This article will not scare you, so you can keep on reading! Just
think of your pond
as a big bowl of soup. Actually, that's how a lot of our pond critters consider
I first became curious about what tiny things lurked in the pond water when
Mrs. Privette's 3rd grade class visited. They took
water samples back to the
classroom to look at under a microscope. A few days later when the sun was
streaming in the
window and bathing my little five gallon aquarium full of polliwogs (see last
month's Critters.: FROGS!
Article), I noticed some tiny
movement: I learned that they were daphnia, also known as water fleas. It was
as tiny as the
period at the end of this sentence but with a magnifying class I could detect
Then I spied a hydra, something I'd never seen before in my life. Curiosity got
the better of me
and I asked Mrs. Privette if I could borrow the microscope for the weekend. The
was really much more active than the pond water as the tiny critters had no
predators there, so I
used it for my viewing. It was magnificent!
All sorts of things I hadn't seen since my high school biology class
shuttled about, or in the
cases of the hydras waved their arms! So I headed to the library and picked up
a few books on
pond water life.
The first thing I was curious about were those Hydras.
They look sort of like a sea anemone with longer waving arms. Mine are pink,
but here's a
picture of a green one or if that's too hard
to see I've scanned a
picture here and elsewhere in this article from "A Golden Guide: Pond Life" by
#574.92. I found out there that Hydras are tiny animals and really are related
to sea anemones!
They can actually be seen with the naked eye and some can get to be 1" long,
although my biggest
one is maybe 7 mm. They eat one-celled animals like protozoa and small
crustaceans which they
capture in their tentacles. They can even move about slowly on their `foot'.
With only my
magnifying glass I have been able to watch them reproduce by forming `buds' that
tiny hydras and eventually break off and become tiny hydras! I've never seen
any in the pond
but I know they are there eating from my `soup' and in turn being eaten by
larger critters, like
maybe dragonfly nymphs? I know that because my water in the polliwog tank came
pond. Under the microscope they look really menacing, but they can't hurt us at
[inset daphnia.jpg align left]Next I wanted to find out what those tiny
things that scooted all
about the tank were. The microscope came in handy here. When one finally held
enough to get an identification, I knew I had discovered some of the
crustaceans the hydras were
feeding on:[insert "bosmina.jpg align right] they were Water Fleas which
Daphnia or Bosmina. We're all more familiar with the crustaceans that are at
the beach -
crabs, but these are similar in that they too have a hard shell and live in
water. They have a pair
of antennae that they swim with and which to me looked like arms..or really
they looked like
the space pod in "2001"! The really good news is what they eat: ALGAE! Of
course they are
very tiny, approximately .5mm. so they don't eat that much algae, but I figure
every bit helps!
They also eat other microscopic animals and organic debris.
[insert "algae.jpg"align left]But all around in that water I saw extremely tiny
about, or maybe not moving much. Some were phytoplankton, such as the algae
Daphnia were eating. One was a green algae called `Volvox" which forms a large
spherical colony of cells and had an [insert "volvax.jpg"align right]eyespot.
Another was an
algae that was more like an animal in that it had the ability to move about. It
looked like this
Euglena. Or was it a protozoa [insert euglena.jpg align left] (another
[insert Protza.jpg align to left of volvax ] They all are so foreign to me!
Others were to forever remain unidentified by me, but many looked like Diatoms,
"TRACHL.JPG" align right]maybe there was one was even one of these Tachlemonas?
better at Microbiology than I am, then you can tell me!
The main thing is that our ponds contain much MUCH more than we are aware of.
All of it is
interconnected. Each and everything we do affects it. So please treat your
pond as a valuable
habitat and respect it's "Critters in the Soup"!
Some sites to visit to learn more about the microscopic inhabitants of your pond
Water World at http://commtechlab.msu.edu/CTLprojects/dlc-
The Digital Learning Center for Microbial Ecology at
The library will contain many good sources also such as:
"A Golden Guide: Pond Life" by Reid, library #574.92 from which I scanned many
"A Guide to the Study of Fresh-water Biology" by Needham, library #591.929
The Biggs are still hoping to get more pictures of their new waterfall and other
improvements up on their Pond Site soon. Kathy reports that approximately 5
dragonflies a day
are currently emerging from their pond, and the froglets are hopping out and all
FLASHBACK: Last month's[insert address] "Critters." article was on Frogs.
wants to alert everyone to the fact that the current May/June issue of "AUDUBON"
features a fantastic article on page 60 - "Vanishing Frogs", with 17 beautiful
To quote a pull-out from the article, "Nearly one-third of U.S. frogs and toads
imperiled." See the on-line Table of Contents at
http://magazine.audubon.org/cont597/index.html She hopes you'll be able to find
a copy of the
magazine and read the article.