Vorticella - The fastest bell in the world?

Vorticella is a genus of single celled organisms living in both marine- and freshwater habitats. The members of the vorticella genus are commonly referred to as bell animalcules because of their shape. The thing that makes bell animalcules unique are their long stalks which they use to attach themselves to a substrate, which could be things like rocks, twigs and even small animals. The stalks of vorticella resemble our muscle fibers but are able to contract a lot faster than our muscles are. If the cell gets disturbed, it’s able to contract the stalk with an impressive speed of up to 6 meters per second as a defence mechanism to get away from danger or possibly scare predators away.

What’s in a rat’s eye

The photos show various parts of the rat's eye. There are many similarities between the eyes of the rat and those of humans, but also some striking differences. A few of these are mentioned here.

The eyeball of the rat’s eye can be rotated to change the viewing direction without having to turn the head. What is special is that rats can move both eyes in opposite directions. This both horizontally and vertically. Researchers at the Max Planck Institute found this out in 2013 and were able to record this using high-speed cameras. They are able to keep an eye on the sky while also looking forward. They can interpret a double field of view. Probably this has evolved in the wild to deal with great threat to raptors.

Triple Stain Wacker 3A

The Wacker 3A staining method (developed by Robin Wacker) is one of the methods which can be used to distinguish cell differences in plants. The images of the cross section of a Rubus idaeus (raspberry) sprout are showing a nice example:

The method is based on the following solutions: 

• Astra blue (2% in distilled water)
• Acriflavin (1% in distilled water) 
• Acridine red (1% in 50% ethanol).  

*All solutions slightly acidified with 2ml acetic acid per 100ml solution.

Tardigrades - Microscopic space travellers

Tardigrades are possibly some of the cutest and most popular microorganisms in the world. These microscopic animals can be found in all kinds of habitats all over the planet from high mountains to deep oceans, and even on the poles. However, even though they are very common almost everywhere you will need a microscope to spot them as most species are around 500 microns in size and the biggest ones rarely exceed 1 mm. Tardigrades are more commonly known as water bears, because of their bear-like appearance when they waddle around in the microworld looking for food. Some also call them moss piglets because of their high abundance in moss and lichen samples.

The darkfield illumination makes the individual storage cells clearly visible inside the body cavity, 

as well as the digestive system in the middle of the animal.

Tardigrades have eight legs which all end in a various number of claws depending on the species. Inside the body we find a lot of anatomical resemblance to larger animals as tardigrades both have a fully functioning nervous-, muscle-, and digestive system as well as primitive eyes. But despite a somewhat complex body structure, the animal only consists of a few thousand cells. Some of these are called storage cells which can be seen in the image above. These cells slush around inside of the animal when it walks. In the front tardigrades have a feeding apparatus consisting of stylets used to pierce the food and a pharynx used for chewing. Most tardigrades are herbivores and eat things like algae and other plant material. However, some species are hunters and eat things like bacteria, single celled organisms, rotifers and even other tardigrades.

Amoebas - Shapeshifters of the microworld

Amoebas are free living eukaryotic organisms capable of changing their shape in order for it to move and feed. This is done by extending cellular projections called pseudopodia (see image). When the amoeba moves it uses these projections as a form of conveyor belt stretching towards the desired way of movement and the cell then fills the pseudopod with its insides called the endoplasm creating a sort of rolling movement as seen in the video below. When feeding, the organism will surround the food with its cell membrane and absorb it into its cell body where it is digested. A big part of the endoplasm is made up of these ingested particles as well as cellular organelles such as mitochondria and the nucleus containing the DNA.

Arcella vulgaris has caught Synura

This testate amoeba lives in the mud and vegetation in standing water and also in the bottom, between algae and other plants. Arcella Vulgaris is a testate Amoeba with loose pseudopodia protruding from the pseudochitine shell. Testate amoebae are amoebae with an umbrella-shaped hard cover. The cover is for protection and is excreted by the animal itself. They nourish on diatoms, unicellular algae, animal protozoa such as flagellates and ciliates.

Nettles - The healthy stingers

The plant urtica dioica, more commonly known as the stinging nettle, is a plant many of us are unpleasantly familiar with. The quite fitting name ‘nettle’ comes from the anglo-saxon word ‘noedl’ which means ‘needle’ and the latin ‘urtica’ means ‘to burn’. The plant is found worldwide but was originally native to Europe. At its tallest, the nettle grows to around two meters and are equipped with medium sized leaves. Despite many myths both the stem and the leaves are able to sting you as both are covered in the tiny needle-like structures called trichomes or spicules responsible for the burning sensation you get after contact with the plant.

Haematococcus pluvialis - The red colored green alga

Haematococcus pluvialis is a single celled green freshwater alga found all over the world. Each cell is encased in a transparent capsule and varies in size from 10-50 microns depending on its life cycle stage, but most are around 20 microns. H. pluvialis can be found in two major stages, active and inactive. In the active stage the algae are motile and move with two long whip-like projections called flagella. In the inactive stage the cells become non-motile encased cysts which are able to tolerate periods without water and huge temperature fluctuations. One of the protective strategies the algae use during the non-motile stage is the production of a molecule called astaxanthin.

Rotifers - Some of the smallest animals on earth

Rotifers are some of the smallest animals on the planet. Most measure under 500 microns, but their size can range from only 50 microns to around 2 mm (2000 microns). They are some of the most common microscopic animals, living all over the world in all kind of environments, like freshwater, saltwater, in moss on trees and in the soil underneath your feet. Rotifers are made up of roughly 1000 cells, some of which are specialized to form organ systems. Despite their incredibly small size they have eyes, a small brain and nervous system, and a dedicated digestive system just like us.

Lumbriculus variegatus - The blackworm

Lumbriculus variegatus, more commonly known as a blackworm, is an oligochaete worm found in many freshwater habitats across Europe and North America. It is technically not microscopic, but very small and to see the details and internal anatomy, we have to use a microscope.

Blackworms are only about a millimeter in thickness, but they are able to reach a length of up to 10 centimeters. Blackworms eat things like microorganisms and decaying plant material. To digest its food, the worm has a dedicated digestive tract running down the center of the body. This is like a miniature version of the human digestive tract and works in basically the same way by squeezing ingested food through the tube with rhythmical massaging movements called peristalsis (see video further down).
Another clearly visible structure in the worm is its circulatory system. The animal lacks a true heart, but instead pumps blood through the blood vessels with several pairs of muscularized vessels able to contract and work as a heart.

Red blood cells - the cells that help you breath

Adult humans carry around 5 liters of blood in their circulatory system. Roughly half of that is cells, and the other half is a pale yellow liquid called plasma. The vast majority of these cells are erythrocytes, more commonly known as red blood cells (RBCs). Our red blood cells are the most abundant cell type in the human body accounting for approximately 70% of all your cells. They measure roughly 7 microns in diameter and around 1-2 microns in thickness.

It looks like a miniature pine forest

Hippuris vulgaris or Marestail is a common swamp and pond plant. This plant is counted among the oxygen plants because the underwater leaves also produce a lot of oxygen and it resembles Elodea (waterweeds) The piece that is a few decimeters above the water looks like a small pine tree. Marestail can form large masses and propagate by means of rhizomes. It prefers to grow on clay soil and in particular in brackish water. A Marestail field looks like a miniature pine forest.

Euglena - part plant, part animal

Cells with a nucleus are called true cells, or eukaryotes, which can be further subdivided into kingdoms like plant and animal. Plant cells and animal cells are different in their components and structure, but some organisms does not fit as neatly into these little boxes and can be tricky to place on ‘the tree of life’. One of these is the single celled organism euglena.

Euglena with clearly visible red eyespots

Stentors - some of the largest single celled organisms in the world

Stentors are trumpet shaped single celled organisms found in freshwater habitats like pods and streams. Due to their shape they are more commonly known as trumpet animalcules. Stentors are some of the largest single celled organism in the world, with the largest species reaching a size of up to two millimeters, and it is therefore possible to spot them in a water sample without a microscope. Stentors are ciliates, which mean that they move and feed with tiny hair-like projections called cilia. They have a large number of these cilia surrounding the mouth which creates a current of water carrying food particles for ingestion. In the opposite end they have a foot which is they use to adhere to a substrate.

Observe the classic trumpet shaped appearance and the clearly visible cilia surrounding the mouth.

Eudorina - a colonial algae

Eudorina is a genus of green freshwater algae. Each eudorina are multicellular colonies consisting of 16, 32 or even 64 individual cells held together by a gelatinous substance made of sugary proteins, or glycoproteins to be a bit more scientific. The individual cells in a colony are not much larger than our blood cells, and the entire colony is about the same size as the width of a human hair. The green color is due to the presence of large chloroplasts inside each cell used for energy production through photosynthesis.

Note the gelatinous transparent matrix surrounding each colony.

Wormwood fluorescence

The photos we see here were taken from a Plescher prepared slide. Plescher fluorescence prepared slides are characterized by a distinctive, three-dimensional, deeply structured honeycomb structure. This is made possible by special, complex, gentle pre-treatment of the hand coupes made of living material that reproduce the sensitive cell contents surprisingly well. The conventional ultra-thin section technology with embedding in paraffin, does not provide the same detailed results. Plescher specimens impress with their specially developed Plescher staining with clarity and gloss, differentiated on a deep black background at 460 - 490 nm excitation wavelength. They are therefore generally ideal for photo stacking.

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.

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.

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.

Colorful microscopic crystals

Vitamin C (ascorbic acid) | Motic BA310E 4X | Moticam Pro S5 Lite | © My Microscopic World

A crystal is a solid where the individual molecules are arranged in a highly ordered three-dimensional structure like we see in grains of sugar and table salt. This is compared to when a substance is dissolved in a liquid and all the individual molecules are floating randomly around. If a liquid with a crystallizable substance is left to evaporate. The individual molecules will rearrange themselves and get bound to one another in a crystalline structure. Depending on which substance it is, both the micro- and macroscopic crystal structure will vary greatly.