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 it.

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 some appendages. 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 aquarium water 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 Reid, library #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 looked like 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 from my pond. Under the microscope they look really menacing, but they can't hurt us at all.

[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 still long 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 scientists call 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 things moving about, or maybe not moving much. Some were phytoplankton, such as the algae that the Daphnia were eating. One was a green algae called `Volvox" which forms a large hollow 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 microscopic animal)? [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, and[insert "TRACHL.JPG" align right]maybe there was one was even one of these Tachlemonas? If you're 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 are

Water World at http://commtechlab.msu.edu/CTLprojects/dlc- me/zoo/zwp0331.html#top

The Digital Learning Center for Microbial Ecology at http://www.paulsmiths.edu/aai/phyto- pics/18-104.jpg

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 of these images.

"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 pond 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 about! -------------------------------------------------------------------------------- ------------------------------------------

FLASHBACK: Last month's[insert address] "Critters." article was on Frogs. Kathy wants to alert everyone to the fact that the current May/June issue of "AUDUBON" magazine features a fantastic article on page 60 - "Vanishing Frogs", with 17 beautiful color photographs. To quote a pull-out from the article, "Nearly one-third of U.S. frogs and toads may be 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.