Welcome to the February 2025 edition of the ISOP Newsletter! I’m thrilled to share this first issue of the year with all of you.

In this edition, we dive into a variety of exciting updates from the world of protistology. Together, we will discover exciting papers recently published in the best scientific journals as well as popular articles on protists. Joel Dacks, Editor-in-Chief of the Journal of Eukaryotic Microbiology, presents a stunning new hand-drawn cover image that captures the beauty of protists. Alastair Simpson, Chairperson of the ISOP Committee on Nomenclature, Taxonomy, and Systematics provides the answer on the question “What is a protist?” Gaytha Langlois will introduce us to the lives of the first women protistologists. Anthony Bonacolta interviews Sina Adl and features a curated selection of popular science books that offer fascinating insights into the world of protists, perfect for those new to the field or those looking to expand their knowledge. Edward Mitchell, one of the authors, introduces the newly published book on hyalospheniid testate amoebae. Omaya Dudin and Gautam Dey present us a groundbreaking initiative that aims to create the expansion microscopy atlas of microbial eukaryotes.

We also provide updates on the recent developments within ISOP’s Executive Committee, including improvements to our communication channels and upcoming newsletter deadlines.

On behalf of the Awards committee, I would like to remind to all student and postdoctoral researchers that the call for the 2025 Holz-Conner Award is open! The H-C award supports the participation of students and financially constrained early-career investigators at ISOP annual meetings. Eligibility for the award is exclusive to ISOP members, with the submission deadline of 15 March 2025. Applications must be submitted through the online form (https://forms.gle/AtRCDEpMwVrbGGWd9).

We encourage contributions from our members—whether it’s sharing your latest research, a noteworthy event, or an obituary to honor a colleague in the field. Please don’t hesitate to get in touch with me if you have something to share in future issues.

I hope you find this issue both informative and inspiring. Thank you for being part of our community, and I look forward to your contributions!

Tomáš Pánek
Newsletter Editor

by Tristan Henderson

Answers at the end of the newsletter.

1) What was first hypothesized as the single-celled precursor of animals?
A) Prokaryote B) Amoeba C) Flagellate D) Ciliate

2) Scientist William Saville-Kent described a colonial choanoflagellate with differentiated cell types, naming it Proterospongia haeckelii—but why did he name it after Haeckel?
A) To honor Haeckel’s contributions to evolutionary theory.
B) He was Haeckel’s student and named it in tribute.
C) To mock Haeckel by naming a key discovery after him out of spite.
D) Because Haeckel had predicted its existence.

3) In 1869, Ernst Haeckel described Magosphaera planula, a mysterious amoeboid-to-multicellular creature that he believed was the missing link between protists and animals. What happened to it?
A) It became a famous lab model like Paramecium.
B) It was never observed again, leading some to suspect he exaggerated his findings.
C) It was later identified as a type of jellyfish embryo.
D) It turned out to be a hoax, created by one of Haeckel’s students.

4) Today, we know that animals are most closely related to choanoflagellates. Which scientist first proposed this?
A) Elie Metchnikoff B) Otto Bütschli C) Alexey Zakhvatkin D) Jean-Baptiste Lamarck