Saturday, May 14, 2011

Planaria to Phantom midge in the Pond

Update on me: It's been awhile since I last blogged, I have still been active and out and about seeing the wonders of nature but I have not been writing. I needed to give my writs a rest.

To take up where I left off I wanted to show some more of the critters I found in the water. While there are a lot of microscopic animals that live in the water and can only be seen with a compound microscope, today I want to focus on those that can be seen with a simple magnifying glass and even without the aid of such devices.

Planarian are one of those animals you read about in text books, study in school and then forget about them but I found one in my sample and was fascinated watching it. Its crossed eyes made it even more endearing. Actually they are ocelli that detect the intensity of the light since they don't like to be in the spot light and prefer the dark side of things.

I think this one just ate.

Planarian are a non-parasitic flatworm in the Turbellaria class and are common in many parts of the world. It reminded me of a snail as it glided along the side of the tank, with ear like projections (auricles) similar to the  snail that shares this tiny tank.   They are famous for the extraordinary ability to regenerate lost body parts and even a whole other self when cut in half.  I didn't have the heart to experiment on it.

This one is next to a scud.

Next up is Hydra shown below. This one is stretched out get grab some food swimming by but they can also go from this half inch long size to the size of a pin head. The tentacles surround the mouth and bring the food to it. Attached to the tentacles and parts of its body are tiny stinging cells used in defense and killing its pray. The other end is a foot with sticky secretions used to hold it to twigs, the underside of the water surface and in this case to the side of the tank.

They reproduce by sex and by budding like a plant but usually during different seasons.  The buds appear when it is well fed. You can see one on the side of the hydra below. Eventually it will break away and have it's own independent life. There has been much written about hydras and I encourage you to find some to observe. Collect some pond water with a few plants and wait.  Usually they will appear in a day or two.  You can see them without a hand lens and are good things for kids to see.


I noticed the critter below one afternoon when I saw a lot of wiggling in the water.  I suspect it was trying to break free and go on to it's next stage of life.  I have not confirmed what it is but I believe it is the pupa of the midge Chironomus. I don't know what happened to it because I never saw it again after I took the photo. Perhaps it just flew away.

Midge Pupa

The next two photos are of Daphnia, members of the order Cladocera commonaly called water fleas because of their jumping motion swimming style. They are between 0.2mm and 5 mm in length; very tiny indeed yet I could still see them without a hand lens and take these photos with my point and shoot Cannon G11.  Like other insects this one is divided into segments but they are almost invisible. The head is fused and bent down towards the body and the rest of the body is covered by a carapace. You can see the brood-pouch in this one.



Pictured below is a Phantom midge larva commonly called a glassworm because of its transparency. It will eventually pupate into a small non-biting midge. They feed on other small aquatic larvae such as Daphnia. This one is facing left and the dot farthest to the left is one of its eyes. The next set of dark spot are air sacs that they use to enable it to migrate up and down the water column in response to atmospheric pressure. When it is low (during the night), they move to the surface. They are fairly common and can be found in lakes all over the world. They can grow up to 2 centimeters in length.

Phantom midge larvae (Charborus sp.)

So that is it for the pond water, I had a fun and learned a lot from this late winter activity.

Check out the other critters at Camera Critter by clicking here.


Gary said...

Really interesting [post!! Boom & gary of the Vermilon River< Canada.

chubskulit said...

Gorgeous critter shots!

Please come and say hi to Wubzy, have a nice weekend!

Becca said...

Nice shots...they are so different from everyone elses!

Trillium said...

Fantastic as usual. I was filled with wonder!

Woodswoman Extraordinaire said...

Wow - this totally brought me back to my high school AP Biology days. Awesome. Thanks!