From Evolution to Invasion: Diatom Stories from IPC13 in Panglao, Philippines

by Eldrin DLR. Arguelles and Hirak Parikh |

Fresh from the 13th International Phycological Congress (IPC13), held from June 8–13, 2025, in the stunning island setting of Panglao, Bohol, Philippines, we’re still buzzing from a week of groundbreaking science, global perspectives, and unforgettable conversations centered around algae.

As early-career researchers working on very different—but equally fascinating—sides of diatom biology, IPC13 gave us the opportunity to share our stories and connect them with the broader phycological narrative.

Hirak presented his work on the long-misplaced raphid diatom genus Capartogramma, revealing its evolutionary backstory through chloroplast rbcL sequences from three species (C. karstenii, C. amphoroides, and C. rhombicum). By building maximum-likelihood and Bayesian phylogenies and anchoring them with a 60,000-year-old fossil horizon from Lake Tanganyika, he was able to place the genus’ split from its sister taxon Prestauroneis at ~44 million years ago—right in the Eocene. Further divergence among the Tanganyikan endemics pointed to mid-Miocene colonization and in-lake speciation, painting a compelling picture of how geological and hydrological shifts shaped diatom diversity.

 

 

 

 

 

Meanwhile, Eldrin shared his research titled:

“Toward a comprehensive understanding of the invasive diatom Cymbella janischii: Insights into microbiome-driven growth promotion and stalk degradation.”

In collaboration with Dr. Shinya Sato (Fukui Prefectural University, Japan), this study investigates how microbial associates may facilitate the invasive success of C. janischii. Using microbiome profiling and co-culture experiments, the research uncovered how bacteria can influence both diatom growth and stalk structure—key traits in colonization and habitat expansion.

 

 

 

 

 

Eldrin was honored with the Best Student Oral Presentation Award, a deeply meaningful recognition from the international phycological community. The award was supported by Phycology Journal and Springer Nature, who continue to encourage early-career research and science communication.

Beyond our talks, IPC13 immersed us in sessions spanning algal systematics, ecology, biotechnology, and climate adaptation—revealing just how multifaceted and urgent algal research is today. Whether exploring ancient divergence or unraveling modern microbial interactions, we came away inspired by the diversity of stories algae have to tell.

We’re grateful to the International Phycological Society, the local organizers in the Philippines, our advisors and collaborators, and the many colleagues who engaged with our work. IPC13 was more than a conference—it was a celebration of curiosity, collaboration, and the boundless beauty of algal science.