Keratella quadrata (Müller, 1786)

Kingdom Animalia, phylum Rotifera, class Monogononta, order Ploima, family Brachionidae.

Depending on the form group, the rear spines are the longest in winter or summer. The animal eats detritus and phytoplankton. The panzer is 200-250 microns large. It is present in standing beta-mesosaprobe waters of all kinds. Wide spread; in this case it was found in a heather fen in the southern part of The Netherlands.

The fast rotating cilia are clearly visible and fairly well defined by the Moticam ProS5 Plus camera.

African mahogany Khaya ivorensis

Khaya ivorensis is the most important tree species that provides mahogany originating from Africa. This tree species can grow to a height of around 40 to 50 meters with trunks up to 2 meters thick. The basis of these trees is often buttressed. Khaya ivorensis prefers wet virgin evergreen forest. In Africa, this wood is traditionally used in canoe building. Different parts of the tree are important in traditional medicine and soap making. This noble type of wood is one of the most important species for wood plantations, because the trees grow quickly and produce high-quality wood that is often used where durability and beauty of the construction are important.

Crystals have been made explicitly visible on the photos using polarization. Crystals in plant tissues are generally waste materials and in some cases (amongst others) may also have a strengthening function.

© www.willemsmicroscope.com

Awaruite, a controversial and almost extraterrestrial mineral

Awaruite is a rare terrestrial nickel-iron alloy, with the formula Ni3Fe, which was found, in the form of nuggets, in black sands and of great specific weight in the Gorge River, on the West Coast of New Zealand.

Font: Google maps

The species was determined by W. Skey, a researcher of the New Zealand Geological Survey Office, in 1885. His analytical results indicated it was this rare alloy, with an element composition more typical of meteorites than terrestrial rocks. The samples those Skey studied, came from a collection of minerals sent by the Warden of the Jackson’s Bay District (Okahu in Māori), also on the West Coast of New Zealand.

Unfortunately, Skey and his director J. Hector did not know the exact location of the founding of these black sands. The information accompanying samples indicated that they had been brought by placer gold prospectors from Barn Bay.

They gave it the name of Awaruite after Awarua Bay (Māori name for Big Bay), where the Awarua River flows out, thinking that this was the correct locality. This mineral has never been found in that bay. All samples came from the Gorge River area, about 15 km north of Big Bay and about 20 km south of Barn Bay.

View of the Gorge River mouth, West Coast, New Zealand. © Long family, Gorge River. (Font)

Which diatoms do we see here?

The Macrofauna Werkgroep Groen Hart Leudal in The Netherlands, found some diatoms in the river Swalm near their clubhouse. It is a challenge to name diatoms if the cell contents are still present in the silica skeleton. The organic content should be removed first with the help of chemicals. Yet an attempt can be made to identify these still living tiny algae, which were caught on video with the help of the Motic inverted microscope AE31E with Motic PlanApo 20X and 40X objectives and the Moticam cameras 1080 and S6.

The Swalm is a small river in Germany and the Netherlands. Its source is in North Rhine-Westphalia, Germany. The Swalm flows into the Meuse across the border with the Netherlands. Its total length is 45 km.

The wetland overgrown with trees and heath/bog areas along the Swalm provide a diverse habitat for fauna and flora. Frogs, dragonflies, damselflies, blue throat, kingfisher and golden oriole are to be found as are water crowfoot, bog myrtle and other rare plants. Brown trout, barbel and chub are at home in the river; along the river banks are also various members of the beaver rat family.

Which diatoms do we see in the video?

What is in a flower bud

The photos of this beautiful botanical preparation - a cross section of a rhododendron's flower bud - show many parts of this special organ of the plant. The names of many parts are indicated in the illustration shown below. It is going too far here to go into depth about all details.

Rhododendron flower bud cross section. 

Sideronatrite from Cabo de Palos (Cartagena, Murcia), a reversible mineral

In the easternmost part of the Murcia region we find the well-known Spanish tourist locality of La Manga del Mar Menor. This inland sea closes to the south by Cabo de Palos, in the municipality of Cartagena.

The hills those define it are found within the Regional Park of Calblanque, Monte de las Cenizas and Peña del Águila. This particular area contains the remains of mining works that began with the Punic period, continued during the Roman Empire and continued until the 20th century.

On one of its highest hills, El Talayón (178 m), we found the “Ferruginosa” mine. This mine has been extensively studied by Morales and Rosell (Morales et al., 2020; Rosell et al. 2017,) due to its particular mineral paragenesis, where chlorides and sulphates stand out.

One of these sulphates is Sideronatrite. This hydrated sodium and iron sulphate, Na2Fe(SO4)2(OH)·3H2O, is found in arid climates. It is found as efflorescences formed by small crystals, of an intense yellow colour, on the walls of the mine galleries. Lanceolated, transparent crystals with a very esthetic orange-yellow colour are observed under magnification.