A worldwide listing and biogeography of freshwater diatom genera: a phylogenetic perspective

Abstract

A listing of the accepted freshwater diatom genera worldwide is presented, indicating the distribution of the genera by continent. Out of a total of 249 genera, 63 (25%) of those genera are endemic to a single continent. The continent with the largest number of endemic genera is Asia, hosting 35 endemic genera. While Asia is also the continent with the most reported genera, a regression analysis showed there is no relationship between the continental richness of genera and generic endemism. Disjunct genera, those found on two continents, represent distributions found in other groups of organisms such as in higher plants, including North America-Europe, North America–Asia and Southern Hemisphere disjunctions. There are certain lineages of freshwater diatoms where the endemic genera are restricted to specific continents: both thalassiosiroid and cymbelloid diatoms have endemics in Asia, while eunotioids have endemics in South America. Future research is suggested combining distributions over space and time related to phylogenetic relationships of diatoms.

Keywords:

• freshwater
• genera
• Bacillariophyta
• biogeography
• endemism
• continents
• disjuncts

Acknowledgments

I am indebted to Dr. Silvia Sala, Facultad de Ciencias Naturales y Museo Universidad Nacional de La Plata, Argentina, for her help with literature, thoughts and a careful reading of the manuscript, as well as Drs David Williams, Life Sciences Department, The Natural History Museum, London, U.K., Maxim Kulikovskiy, Papanin's Institute for Biology of Inland Waters Russian Academy of Sciences, Borok, and Institute of Plant Physiology, Russian Academy of Sciences, Botanical Street 35, 127276, Moscow, Russia, and Rex Lowe, Bowling Green State University and University of Wisconsin, Madison, for their critical reading of the manuscript and helpful suggestions. Bart Van de Vijver, Botanical Garden, Meise, Belgium, kindly provided a list of genera from the Antarctic region.

Disclosure statement

No potential conflict of interest was reported by the author.

Supplemental data

Supplemental data for this article can be accessed at https://doi.org/10.1080/0269249X.2019.1574243. References marked with an asterisk are cited in the supplemental data.