Protozoan – 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 in its extended state

Vorticella in its extended state

Vorticella in its contracted state

Vorticella in its contracted state

 

pH of Living Water Samples

One of my ongoing projects is studying, if and how, the population of Diatoms and Desmids varies as the pH of their watery environments change. It is also a project that I administer on the iNaturalist website.

I have tested 17 bodies of water since I began this project a year ago and the pH factors range from 6.2 to 8.3.  Because of its accessibility, the most frequently sampled water is a local vernal pond. I have tested its water six times and the pH has always fallen between 6.6 and 6.7.  By far the most numerous Diatoms in that pond are of the genus Pinnularia; so it serves well as a point of reference.

It is too soon to draw any firm conclusions but one pattern seems to be emerging. I have found only one species of Pinnularia in waters whose pH exceeded 7.5 – and it was of a type that I have never encountered in waters below that level.

In the coming months (years?), as my sample size grows, it will be interesting to see if this pattern is confirmed or is just an illusion – and what other patterns might be found. It is always informative, exciting, and lots of fun when a project works out as well as this one has. And that is what amateur science is all about.

The only Pinnularia found in water with pH above 7.5

The only Pinnularia found in water with pH above 7.5

A typical Pinnularia found in waters with pH below 7.5

A typical Pinnularia found in waters with pH below 7.5

 

 

Vernal Pond

A vernal pond (or vernal pool) is a relatively small, temporary body of water that usually reaches its maximum depth in the Spring; then will dry up at some point during the year. They can serve as breeding grounds for amphibians (frogs, toads, and salamanders) but are not permanently inhabited by the adults. They never contain fish. This means that the creatures at the top of the food chain are quite small; typically the size of a water flea. The microscopic wildlife is abundant, even dominant.

2014-0414aOur local vernal pond is beginning to fill up with water from early rains and snow melt. At its largest it will measure about 60ft x 40 ft; at present it is less than 1/2 that size.

Total Lunar Eclipse

In the early morning hours of April 15, 2014 there will be a total eclipse of the Moon. A lunar eclipse occurs when the Moon passes through the Earth’s shadow in space. If the Earth were airless, its shadow would totally obscure the Moon and it would be completely black (invisible). The Earth, however, has a significant atmosphere and it causes the Moon to appear to be red. Sometimes the Moon at totality is pale, nearly pinkish; other times it can be what is often described as blood red. The intensity of the coloration varies with the atmospheric conditions at the time (presence of water droplets, dust particles, and clouds along the edge of the Earth) – none of which are completely predictable.

2014-0412a

Rotifers in Motion

Rotifers are very active mico-organisms. In order to photograph them in any detail it is necessary to catch them in a restive state or slowed down with methyl cellulose.

Bdelloid Rotifer – Genus Rotaria

Bdelloid Rotifer – Genus Rotaria

 

Although still photographs can be useful in showing their structure, they reveal nothing about how the Rotifer moves or behaves. Modern technology has solved that problem by making videos through the microscope possible. Follow the link below to see how I caught a Rotifer moving about in its watery environment.

http://youtu.be/L-_wiO7J_Vk

 

Anglewing Butterfly

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

Anglewing Butterfly – Genus: Polygonia

Anglewing Butterfly – Genus: Polygonia

 

Coltsfoot

The appearance of an American Robin as the first sign of Spring may, or may not, be an urban myth. In my little corner of the world, however, the first sign is always the Coltsfoot; a plant that some folks incorrectly refer to as a wild Dandelion. One sure way of telling a Coltsfoot from a Dandelion is that the Coltsfoot does not display any leaves until it develops seeds, several weeks after the flower first appears.

Coltsfoot - Tussilago farfara

Coltsfoot – Tussilago farfara

Observing the Sun (3)

Two views of the Sun are available to the amateur astronomer. The first is the view as seen through the solar filters previously discussed – that of visible light; also called white light or integrated light since it is composed of all frequencies of the spectrum visible to the human eye. The cost of a white light filter varies with its size but can usually be obtained for $100 or less.

View of the Sun in White Light

View of the Sun in White Light

 

The second is a view that has only recently been made available to the amateur. It is that seen through special filters which transmit only light rays in the hydrogen alpha frequency. Although more expensive than white light filtration, at approximately $1000 it is within the reach of serious amateurs.

View of the Sun in Hydrogen Alpha

View of the Sun in Hydrogen Alpha

 

Observing the Sun (2)

What most consider the ideal way to observe the Sun is with a full-size filter; one that covers the objective, not the eyepiece. Eyepiece filters are extremely dangerous and should never be used. They can easily shatter from the concentration of heat and, as mentioned in a previous post, you could never pull your eye away quickly enough to prevent permanent damage.

Full size filters can be made of glass, Mylar, polymer, or Baader safety film. Despite their odd wrinkled appearance, Baader filters produce the brightest, sharpest and highest contrast images.

2014-0404a

Attaching a suitable camera to the telescope eyepiece and projecting the image onto a laptop screen will provide an absolutely foolproof way of observing the Sun as well as making it possible to permanently record the solar appearance.