Introduction

Micrasterias thomasiana

Desmids are green algae that are found exclusively in high-quality freshwater. For most people, desmids are unfamiliar because they are so small. The smallest species are about 1/100 mm in size, while the largest are 1 mm, just visible to the naked eye. You need a microscope to study them.

Desmids are highly symmetrical and have a very attractive appearance, as shown in the photo on this page. This is why they are called 'Sieralg' (beautiful algae) in Dutch. A desmid consists of a single cell that is often deeply constricted in the middle, with the cell nucleus located exactly at that midpoint.

Desmids typically reproduce through cell division, but occasionally a process occurs where two cells come together (conjugation) and the contents of both cells fuse to form what is called a zygospore. This is a form of sexual reproduction. From the zygospore, two new cells can later emerge.

In 2007, I became interested in this group of algae and began examening the distribution of desmids in the province of Drenthe.

This website presents some of the results of that research and shows photos of desmids found in Drenthe.

The atlas 'Sieralgen in Drenthe' summarizes all the research findings.

Between 2007 and 2021, desmids were sampled from fens, ponds, and other waters across the province of Drenthe. This led to the discovery of more than 500 species, some of which have been described as new to science.
This atlas documents the results of the research. It discusses the locations, ecology, and dimensions of the species found. Additionally, distribution maps and graphs with the measured pH and EC (electrical conductivity) of the found desmids are provided. These data are supplemented with light microscopic photos, and for some species, photos taken with a scanning electron microscope (SEM) are included.

This atlas is self-published through print-on-demand and is available via:

https://print.24bookprint.com/books/362358

• The price is €55,– (excluding shipping costs).
• Format: 19.3 x 26 cm, over 4 cm thick, hard-cover, weight 2.1 kg.
• 666 pages in colour with over 4700 photos, illustrations, and graphs.

Although the text is in Dutch, an English summary of the introduction chapters, with an explanation of often used words in Dutch can be found in chapter 7.