This volume honours Luc Ector as a diatom scientist with 17 contributions, presenting new findings on one of Luc's favorite passions, diatom research. Luc was an inspiring mentor motivating many young (and not so young) colleagues worldwide. This is reflected in the subject of many contributions in this volume. A new genus, Lucectorea gen. nov. (Tudesque et al.), and numerous new species such as Pinnularia ectorii sp. nov. (Potapova et al.) and Rimoneis ectorii sp. nov. (Marquardt et al.), are named after him.

This Memorial volume includes important revisions and additions to our current knowledge of several freshwater diatom genera (e.g. Abarca et al.). Luc was a keen diatom taxonomist and ecologist who fully understood the value and importance of historic diatom material as a tool for our modern understanding of diatom species. Several contributions in this Memorial volume such as those on Stauroneis acuta (Wadmare et al.), Brachysira vitrea (Van de Vijver et al.), of Frustulia saxonica (Jüttner et al.), start with the analysis of historic type material to disentangle difficult and confusing relationships.

During a beer reception at one of the last French Diatomist Meetings, the editors jokingly conceived the plan to compile a Festschrift for Luc Ector's 65th birthday. They could never have imagined that only three years later they would have to invite his friends and colleagues to publish an article in this volume in his memory. The editors would like to thank all contributors and reviewers for their careful work in shaping this memorial volume.

Luc's enthusiasm, kindness and immense diatom knowledge will never be forgotten, and this Memorial volume will contribute to his legacy and as such will represent a valuable piece of work for future generations of diatomists.