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Bruce Taylor
05-22-2010, 09:26 PM
A bunch of people usually click on the links when I post one of these, so there must be a bit of interest.

Hydras are freshwater polyps, related to jellyfish and sea anemones. This one is hunting, and seems to be attracted to the movement of small crustaceans and rotifers. The tentacles have stingers on them, but I have yet to see a hydra actually kill and eat something.

I filmed it using an improvised "semi-darkfield" technique, tipping the objective lens of the microscope away from the light source so that the creature is illuminated by indirect light.

Best in full screen, with sound on.

Eerie creature (http://www.youtube.com/watch?v=pOCEbsDUno4)

Milo Christensen
05-22-2010, 09:43 PM
You're doing some good work with that 'scope. I've never had any reason to think utube was anything other than a bandwidth hog for narcissists, but I sort of had this epiphany that all these millions of utube videos might actually have a great deal of educational value. Nothing like a bunch of short clips to introduce the topic of freshwater protozoans before the kids start using the microscope. Thanks for the links, some of the ones from the classrooms sure do bring back memories of teaching high school biology.

Bruce Taylor
05-23-2010, 07:59 AM
I've never had any reason to think utube was anything other than a bandwidth hog for narcissists, but I sort of had this epiphany that all these millions of utube videos might actually have a great deal of educational value.

There's a Spanish guy named fpelectronica -- another amateur -- who is compiling what he calls "un modesto Video Atlas de Microorganismos." It's very much in the spirit of the 19th century gentleman scientists who did so much of the original work on freshwater microorganisms (and hundreds of their old books and articles have also been scanned and made available in the Internet Archive, Google Books, etc.) It seems to me that the availability of material like this could spark a small revival of independent scholarship. Tens of thousands of new species remain to be found and described, if amateurs acquire the resources and skill to go after them.

As it is, with all the info. available online, I still can't identify the genus of half the stuff I've found. Occasionally I'll upload one to YouTube (http://www.youtube.com/watch?v=pmcvUf_H_bg), hoping somebody will be able to name it, so far without luck.


I always get a feeling that something is about to happen and I'm never disappointed.

Glad to hear it, Doug. There's lots of drama, down there, but I don't catch much of it on film. Here's a carnivorous flatworm sucking the guts out of a tiny crustacean:

Yuck (http://www.youtube.com/watch?v=8TEgj9uLytM)

and a really short one of a frantic mini-swan:

Single-celled swan, rocking out (http://www.youtube.com/watch?v=4DEB8AIQef8)

McMike
05-23-2010, 08:20 AM
very cool!!!

ishmael
05-23-2010, 12:44 PM
My college course of study was biology, and we watched a variety of hydra go about their bee's knees. While we were encouraged to go to local ponds and collect our own, most specimens came from a biologic suppy house.


A shudder of glee and horror at what these critters were up to. Like watching "Deliverance" but without the music. A microscope opened a whole 'nother universe.

Bruce Taylor
05-23-2010, 01:43 PM
A shudder of glee and horror at what these critters were up to.

The Dutch cloth merchant Antony van Leeuwenhoek was the first to describe them, in the 17th cent., and he was clearly unable to tear himself away from the lens.

From one of his charming letters to the royal society:


What seemed to me remarkable and wonderful was that these little animals would oft-time let down their horns so far that you would think, on seeing through the microscope, that they were several fathoms long.

At one time or another I let the draughtsman have a look at the horns as they were being stretched out, or anon pulled in; and with me he was forced to exclaim "What wonders are these!" For as the creature pulled in its horns, they became perfectly round, and the closer they got to the head, the thicker they became, and when they were pulled right in, they formed a still bigger round blob.

. . . Furthermore, in this water there were so many sorts of animalcules that I had never discovered in any other waters, that I was mazed to see such a diversity of structures; and each too had its own proper motion, wherefore I many times looked upon these delightsome and wondrous little creatures, which quite escape the bare eye.

Woxbox
05-23-2010, 02:49 PM
Fascinating. Reminds of studying pond water when I was a kid. Also of a favorite Far Side cartoon.

A scientist is pictured staring into a microscope. He has a hand raised in the air, holding his wallet. The caption (as best as I recall): "Professor Dawson wanders into a bad corner of the petri dish."

Concordia...41
05-23-2010, 07:48 PM
Yuch is right, but all creatures great and small ...