Rotifers are the giants of the microbial world. Some are only 1/10 millimeter long but this large one, even in its partially contracted state is almost a half millimeter in length. To the naked eye it might be seen as a featureless dark speck, and that would place it at the upper limit of what is normally considered to be a microbe.
By far the most numerous diatoms in this area are those belonging to the genus Pinnularia. One reliable source places the number of Pinnularia species at over 2,200.
Under the microscope some are identical in appearance but special equipment, beyond the reach of the amateur scientist, might show that they are a different species. As one prominent biologist once said – “To assign a genus to a diatom takes courage. To assign a species is simply foolhardy.”
Here are several different but common types. Note the differences in size, shape, and frustule (outer shell) patterns.
After a few days, a slight film developed on top of the water from the algae sample. I drew a drop from the film and found that it was full of large, active protozoan life. Some of the more interesting were members of the Class Spirotrichea. I introduced some methyl cellulose to slow them down and got some very nice images.
On a recent trip to a local state park I filled a pint jar with algae and water from the shallows of a small lake. The cluster of algae was composed mostly of two types of Spriogyra intermixed in a single mass.
The first butterfly to be seen in the Spring is the Holly Blue Butterfly. Quite small, it has a wing span of only about 3/4 inch. The underside (seen above) is a pale blue but the upper surfaces are more brilliant. The upper surfaces are usually only seen when the butterfly is in flight. When it comes to rest it holds its wings together, above its back, and the underside is all that can be seen.
As one might expect, the variety of micro-life in a pond is greater than that in a patch of moss. In addition, the size of the creatures in pond water is also larger. Diatoms are an excellent example. Most diatoms in moss are in the 25-50 um range. The diatom above, from the aquarium of pond water I recently established, is probably the largest of its type that I have come across. It measures out at a very large 200 um.
The field-of-view of my 40x objective is about 150 um, not large enough to accommodate the entire cell. Rather than switch to a lower magnification, and lose some detail, I photographed the diatom in two parts and stitched them together in Photoshop Elements.
With the exception of fruit trees, we don’t often think of trees as having flowers. Technically, the flowers of a fruit tree (apple, cherry, etc.) are called blossoms because they become fruits.
In any event, we are at the time of year when the Red Maples are producing (true) flowers. Quite small (the one on the left is only about 1/4 inch), they are brilliant red and quite beautiful. Often too high off the ground to be easily seen, the ground surrounding the trees will be filled with hundreds of them.
The second spring flower to make its appearance in our area is always the Common Periwinkle (Vinca minor); a beautiful little flower less than an inch in diameter. More visible than its flowers, although often overlooked, are the leaves of the plant which provide a popular and sturdy ground cover. The Common Periwinkle is such an effective ground cover that it is widely sold for that purpose.
Although they have been growing freely in over 30 U.S. States since their introduction from Switzerland in the 1700’s, the Common Periwinkle is still officially listed as an invasive species.
Without fail the first flowers to make an appearance in our area are the Coltsfoot (Tussilago farfara). Although they look a lot like Dandelions they are actually a type of Sunflower. The flowers appear on stems with no apparent leaves. After the seeds appear, so will the leaves, which some folks say look like a colt’s foot in cross section. Thus the common name.
From a more technical standpoint, I find it interesting that “farfara” is the only recognized species in the genus “Tussilago”.
Nitzchia sigmoidea is one of those colonial diatoms that I mentioned in yesterday’s posting that joins with its fellow cells in a side-by-side fashion. This colony was very large. About 25 cells are visible here but the entire grouping contained at least 100 diatoms.