Wednesday, 8 April 2020

Hydra - The immortal monster of the micro world

A hydra might look a bit like a miniature octopus, but it is actually a lot closer related to jellyfish. It is relatively common in both tropical and temperate regions where it can be found in slow flowing streams, ponds and other freshwater habitats. At one end the animal has one to 12 tentacles which all have their origin around the mouth. In the opposite end is a ‘foot’ allowing the hydra to attach to a substrate. The body can measure up to 10 mm when fully grown and stretched.

Note the small buddig of a new hydra on the lower side.

Wednesday, 1 April 2020

Tricky glare

The name Chalcanthite is derived from the Greek, chalkos and anthos, which means copper flower, it is a richly colored blue / green water-soluble sulphate mineral CuSO4 · 5H2O. It is often found in the late-stage oxidation zones of copper deposits. Chalcanthite dissolves easily in water, just like ordinary copper sulfate that is available on the market. Because of this property, Chalcanthite is more common in arid regions. The crystals photographed here are from Bulgaria.


Wednesday, 25 March 2020

Yeast - The helpful and harmful organism

Yeast is a big part of our lives and human culture in general. It is involved in everything from alcohol production and bread making, to scientific research and probiotics. However, some yeasts can also be pathogenic and cause human infections.

Yeasts are unicellular fungi that mainly metabolism sugars for energy. They are very common in the wild where they can be found on the skins of fruit and other sugar-rich places like cereal grain crops. Even though yeast plays a huge role in many aspects of our everyday lives, most species are only about 4 microns in diameter, which is about half the size of our red blood cells. in comparison, a single human hair is roughly 80 microns thick.


Thursday, 19 March 2020

How to avoid extreme highlights from reflecting surfaces

Optimize your illumination system. Extremely applicable in case of image documentation by a digital camera.

Reflected light is polarized light. This physical property is known by everybody who is doing serious photographies with a single lens reflex camera.

Motif: Landscapes, technical buildings, any kind of documentation for newspaper or book.
Solution: A rotatable polarization filter mounted in front of the objective.


Polarization filter of a reflex camera (source)

Rotate the filter until contrast is maximum, reflections are minimum. A new viewing angle requires a new adjustment.

Picture taken with Pol-Filter, interior visible vs Picture taken without Pol-Filter (source)

Wednesday, 18 March 2020

Ithytrichia lamellaris: ‘Not observed in a hundred years’

In a little stream in Limburg, the southernmost province in the Netherlands, an apparently unknown animal was unexpectedly found by members of the Macrofauna Workgroup Green Hearth Leudal. During the determination an animal with a very remarkable shape was noticed in a partly transparent tube, which was no larger than 4 mm. The segments of the abdomen of the animal were lobed like bellows of an accordion. In addition, there was a drop-shaped appendix on each lobe. This had to be something very special. Internet gave little to no result. Until an article with a photo attracted attention. In the photo you could see an animal that looked like the captured one. The headline: ‘Not observed in a hundred years’, indicated that something strange might have been caught?


Wednesday, 11 March 2020

Tardigrades - Some of the toughest, and smallest, animals on earth!

Tardigrades are some of the smallest animals on the planet. Most are around 500 microns (half a millimeter), but newly hatched tardigrades can be 10 times smaller than that. And the biggest ones only reach about a 1.5 millimeters. Tardigrades are more commonly known as water bears. This is because of their bear like appearance when they waddle around looking for food. But, unlike a bear, tardigrades have eight legs which all end in several claw-like toes. Most tardigrades are herbivores and eat thing like algae and other plant material. However, not all tardigrades are grazers, some are hunters and eat things like bacteria, single celled organisms, rotifers and even other tardigrades.

Living tardigrade from the genus Ramazzottius.

Tardigrade from the genus Milnesium mounted in hoyer's medium.

Wednesday, 4 March 2020

Granulomatous inflammation cat

A granulomatous inflammation occurs when the body, for example, cannot properly clear up an infection or a corpus alienum (foreign body). A well-known example of this is a tubercle (TBC) in an infection with mycobacteria. Then there grows a kind of chronic inflammation with accumulation of neutrophilic polymorphonuclear leucocytes, macrophages, epithelioid cells and giant cells (large erratic cells with multiple nuclei). You can also find lymphocytes and plasma cells in it.


Wednesday, 26 February 2020

Skin Cells

The skin cover the entire body and is our largest organ. It functions to protect the internal organs from mechanical, thermal, and chemical exposure as well as prevent evaporation of body liquids and of course also act as a barrier for pathogens. The outermost layer of the skin is called the epidermis. This layer varies in thickness depending on the location, but in general it is about 0.2 mm - 0.5 mm, or 200-500 microns thick. The epidermis can be subdivided into five (actually six) individual layers all made up mostly of skin cells, called keratinocytes. In fact 90-95% of the cells in the epidermis are keratinocytes.


Thursday, 20 February 2020

You need a unique sample for your teaching lesson? Have a look into your rain gutter.

It’s real life: Sometimes the good things are closer than expected. Your rain gutter not only disposes the water from your roof, but also collects detritus from its colonizers such as mosses and lichens. It’s an extreme biotope: wet and cold in winter, even freezing, dry and hot in summertime. Only few microorganisms survive this extreme change.

One of them just recently came into spotlight. In April 2019 the Israeli space probe Beresheet* crashed onto the surface of the moon; 585kg of weight caused a small caldera. Aboard there were several thousands of Tardigrada, also known like Water Bears. As they had been transported in dried condition, and apparently no water seems to be available on the moon by fog or rain, the probability of life on the moon in 2020 still is quite low.

No need to travel so far to meet this astonishing group of animals. Take a sample of detritus from your rain gutter, if dry, first let it soak in rainwater. After a few days at room temperature it is time to check the water sample. Tardigrada may be fixed on the surface of moss leaves, so it makes sense to place a moss stem on the glass slide and to strip off the leaves by using two tweezers, one fixing the stem, one stripping off the leaves against the direction of growth.

A dead Tardigrada: Sectoral structure of body clearly visible.

Wednesday, 19 February 2020

Volvox bloom

Volvox is a popular alga among microscopists because of the beautiful images it produces under the microscope. The volvox in the video was unexpectedly found in a pool in Eindhoven, the Netherlands in early November 2019. There were so many of these species present that one could speak of a bloom.

The green alga Volvox is a colony of cells that have started to work together. Some cells catch the light, others provide movement or reproduction. They have become so dependent on each other that you can speak of a multicellular organism.