Vorticella

Some protozoans are difficult to identify to the genus level because they have few distinctive features that are readily visible. This is not the case with the Vorticellas which are cup shaped and on a long stalk. They are easily recognized except, possibly, when in the free-swimming state immediately following reproduction. They reproduce by fission but only one of the daughter cells keeps the stalk, the other will swim about looking for a suitable place for attachment. When one is found, it will grow its own stalk and affix itself to the substrate.

Vorticellas feed by extending their stalks and drawing bacteria (and other edibles) into their oral opening with a ring of beating cilia. At the slightest disturbance they coil up their stalk in spring-like fashion and pull their body into a ball. This extension and contraction goes on constantly but trying to slow it down with methylcellulose is only partially successful. In the presence of this chemical the Vorticellas tend to go into their contracted state and stay there, making observations of their extended state impossible.

Vorticella (Extended)
Vorticella (Extended)
Vorticella (Contracted)
Vorticella (Contracted)

Anglewing Butterfly

There are at least a dozen different Anglewing Butterflies (Polygonia ) – wingspan of about 2 inches, orange colored with similar (but not identical) dark markings, and a fuzzy green body. They are one of the first butterflies seen in the Spring.

Anglewing Butterfly
Anglewing Butterfly

Brown Marmorated Stink Bug

I found this insect (Brown Marmorated Stink Bug – Halyomorpha halys) on our front porch. Keys to identification are its shield shape, dark triangular markings on the abdomen and light bands on its dark antennae. This is an invasive species from Asia that was first detected in Allentown PA in 1996 and is a serious agricultural pest.

Brown Marmorated Stink Bug
Brown Marmorated Stink Bug

Difflugia

If there were such a thing, Difflugia should get a prominent place in the Protozoan Hall of Fame. They are amoebas that build a shell out of sand and soil particles that they find in their environment. That shows a lot more sophistication than we usually attribute to a primitive little blob of protoplasm. When they want to feed, or just move about, they extend pseudopods through the bottle-neck opening shown on the upper left of this image.

Difflugia
Difflugia

Craters: Hercules & Atlas

Most observers prefer to study only the lunar features that are close to the terminator, the line that separates the dark regions of the Moon from the illuminated areas. This is where the shadows are most prominent and vertical features (crater rims and mountains) are shown in strong relief. Personally, I think that it is just as interesting to observe lunar features when they are far from the terminator and fully illuminated. It is under these conditions that the various tonal differences of the lunar surface are best seen. Here are the craters Hercules and Atlas under both lighting conditions.

Hercules & Atlas
Hercules & Atlas

 

Pecopteris

Southwestern Pennsylvania is coal country, and many of the fossils found in this area are of plants that date back to the Pennsylvanian Period of the Paleozoic Era (280 million to 325 million years ago). Not to be confused with modern ground dwelling ferns, Pecopteris was part of a tree-like plant called Psaronius, that reached heights of 15 meters (50 feet) and had a base over 1.5 meters (5 feet) in diameter. What we see in this fossil is not a plant in its entirety, but just the leaves of a “tree”. The reason the leaves have their own name is that prior to the discovery of an entire fossilized Psaronius, Pecopteris was believed to be a self-contained fern that grew at ground level.

Pecopteris
Pecopteris

I AM BACK

After an extended absence I am back. Not just to here, but to a number of other aspects of my life. The length of my absence from other aspects must be measured in years, not just weeks. But I am back none the less

Filamentous Algae

The long and slimy filaments of green algae that often cover the surface of stagnant ponds (and now blooming in Lake Erie) may be repulsive to the naked eye, but some can be quite attractive under the microscope. Here are an unremarkable algae and a strand of Spirogyra, generally considered to be the most beautiful of the filamentous algae.

Filamentous Alga – Genus: Unknown
Filamentous Alga – Genus: Unknown
Filamentous Alga – Genus: Spirogyra
Filamentous Alga – Genus: Spirogyra

Mold – Rhizopus

Common names can be useful in casual circumstances, but can also be the cause of much confusion and many inaccuracies. Many of the molds that grow on bread belong to the genus Rhizopus and so we call all species of Rhizopus “Bread Mold” – even though there are over 100 different species of Rhizopus and not all of them grow on bread.

Another problem is that the name Bread Mold promotes the false assumption that molds can be classified by the type of material that they grow on. If Bread Mold grows on bread, then the mold that grows on tomatoes must be different, perhaps Tomato Mold. And the mold that grows on plums must be Plum Mold – and on, and on, and on. Even though it is so prevalent that most “household” molds are likely to be Rhizopus, we would never refer to them as Bread Mold unless they were actually growing on bread.

Having said all that – this lovely specimen of Rhizopus was not found growing on bread or on anything else, it was in a tub of rainwater.

Mold Spore Case – Genus: Rhizopus
Mold Spore Case – Genus: Rhizopus

 

Tardigrade (Water Bear)

Tardigrades are fascinating little creatures with a phylum all their own. If they dry out they go into a state of “suspended animation” but can be revived at a later date by the simple addition of water. It would be interesting to see how many times a single Tardigrade could go through that process before it failed to reanimate. Of course, there are many variables that would enter into the equation: The length of the active and inactive periods, the intake of food during the active state, and numerous other factors related to both the Tardigrade itself and its environment.

Water Bear - Phylum: Tardigrada – Class: Eutardigrada
Water Bear – Phylum: Tardigrada – Class: Eutardigrada