Wednesday, 13 March 2019

What’s in a buttercup bud?

The images shown are taken from a beautifully colored prepared slide from the archives of the Royal Antwerp Society for Micrography. The slide is already quite old, from 1988. It shows a cross-section of a bud of the buttercup (Ranunculus) In spite of the age of the slide, the colors are still clear and fresh. Coloring has been carried out with the dyes sun-yellow, crocein scarlet and astra blue. The very thin coupe has been embedded in the resin Euperal. The use of yellow and blue colored dyes, resulted in green colored plant tissues, which is quite special.

Wednesday, 27 February 2019

Cyclonexis erinus a rare organism?

Cyclonexis erinus (Chrysophytes, golden algae) is considered to be an algae, difficult to observe. The specimen shown in this video has been found in an aquatic sample taken from a small fen in the Nature Reserve ‘De Teut’ in Belgium, in February 2016 (during quite cold weather).

Only few references about this algae can be found in literature and on the internet. Only a very limited number of the species Cyclonexis sp. is known. Cyclonexis sp. lives in cool, lime poor mountain waters and in acid fens containing Sphagnum. It is mentioned that it is not so rare as is sometimes assumed. It was discovered that these algae disintegrate very quickly when external conditions are changing, causing it to disappear from the aquatic sample.

Wednesday, 13 February 2019

The open structure of a water plant

Hippurus (Hippuris) vulgaris or mare’s-tail is a very common swamp and pond plant. This plant (a helophyte) is counted among the oxygen plants because the underwater leaves also produce a lot of oxygen and resemble water plague (Elodea). But the piece that raises a few decimeters above water looks like a small pine tree. Mare’s-tail can form large masses and continue spreading through means of rhizomes. Mare’s-tail grows preferably on clay soil and especially in brackish water.

Wednesday, 30 January 2019

A fluorescent flea

Almost daily we have to deal with arthropods such as insects, spiders and their kind around us. Yet we realize less often that these animals can provide a beautiful light show.

Fireflies and other bioluminescent animals produce their luminous shine through a chemical reaction. Other arthropods produce light via fluorescence. At certain wavelengths of light including ultraviolet light, molecules in their exoskeleton absorb this light and radiate it again in a different color with a (longer) wavelength, (there are 'excited electrons' involved, but let's skip the details here)

Wednesday, 16 January 2019

Protected against harsh conditions

Helm grass is what we encounter in the dunes among others in the Netherlands. The Ammophillia arenaria can withstand the salty water and salty sea air. Ammophillia arenaria can be planted on all types of soil, only on clay soil it is best to make the soil poor with masonry sand. The soil must be calcareous.

Thursday, 3 January 2019

Fibrosarcoma cat

A fibrosarcoma is a malignant tumor of mesenchymal connective tissue cells. Fibrosarcoma mainly occurs as a solitary tumor in the older cat. It can occur in several parts of the body. Usually on the trunk and often also between the shoulder blades, because injections are usually given here. First there is an injection site reaction that degenerates neoplastic. The rabies vaccine is known to be a possible cause of this. It is a malignant derailment of the dermal and subdermal connective tissue cells. The sarcoma grows locally very infiltratively and aggressively, not metastasizing quickly. But if so, then to the lungs and lymph nodes. Fibrosarcoma can also occur in young cats. In these cases it is often induced by a virus and there are multiple tumors over the entire body.

Wednesday, 19 December 2018

Easy observation and filming of plankton

When investigating water samples within the framework of hydrobiology, it is very easy to observe and film plankton with the Motic AE31E inverted microscope and the Moticam 1080 camera. The plankton containing water sample is stored in a culture dish, the bottom of which is formed by a calibrated cover glass. The dish is simply placed on the microscope stage. The Moticam 1080 is connected to a monitor. As soon as an interesting organism appears on the monitor screen, it only needs a simple mouse click to record the image.

Wednesday, 5 December 2018

A Casuarina cunninghamiana from Australia

The Casuarina cunninghamiana or the River She-Oak is a large, fast-growing, pine-like tree native to the east of New South Wales and Queensland, Australia. The tree, an evergreen, has thin needle-like, flexible green twigs practically without leaves. An image of a cross section thereof is shown here. The epidermis shows a structure which is a little similar to that of pine needles.

The Casuarina cunninghamiana is one of the tallest trees of its kind and can reach a height of 30-35 m. Its straight stem branches are quite low and its bark is greyish brown, rough and cracked so that it often comes loose in strips. The plants can easily be grown from seeds. In some countries it is considered an invasive species because it can surpass indigenous plant communities.

Wednesday, 21 November 2018

How do you look after four times shedding your skin

An adult female mosquito lays her eggs on the water surface. This can be in a ditch, in pools in the floodplains, in a pond or in the rain barrel. Each species has its own preference. The number of eggs that are laid is very different from species to species and can be up to 300 at a time. After a few days, the larvae crawl out of the egg. These larvae feed on algae, microbes and other substances in the water.

Wednesday, 7 November 2018

No movement without motor nerve cells

Nerve cells or neurons are cells that you need for example when picking up a pen or in the reaction to contact with a hot or cold object etc. There are three types of nerve cells: sensory, motor and relay nerve cells.

Sensory nerve cells can be found throughout the body. The sensory nerve cells are the cells that collect information, e.g. if something hurts or feels hot or cold etc. The sensory nerve cells send this information to the central nervous system (brain and spinal cord) where it is processed.