Choanoflagellates have three distinctive claims to fame: they are the closest, living, unicellular relatives of animals; they are a major component of aquatic microbial foodwebs; and one group is remarkable for its siliceous basket-like coverings. This landmark book offers a unique synthesis of over forty years of choanoflagellates research. Key areas are covered, from the phylogenetic evidence supporting the sister-group relationship between choanoflagellates and Metazoa, to choanoflagellate distribution and diversity in marine and freshwater environments. The structure and assembly of choanoflagellate loricae is also presented together with a full discussion of a novel example of 'regulatory evolution', suggesting that the switch from nudiform to tectiform cell division and lorica production was achieved by a sudden reorganisation of existing structures and mechanisms. Providing an authoritative summary of what is currently known about choanoflagellates, this title will serve as a foundation upon which future research and discussion can take place.

'We look around and see a world full of animals, plants and fungi, but our eyes are deceptive. Most life on Earth is microscopic. Amongst the great diversity of single-celled life, the choanoflagellates deserve our special attention. As well as being important ecologically, choanoflagellates occupy a position of pivotal significance in the evolution of life. They are the closest single-celled relatives of the animal kingdom. To understand how animals evolved, we must study choanoflagellates. In this landmark book, Barry Leadbeater ranges from ecology and evolution, through to cell biology and ultrastructure, to reveal the secrets and the significance of these important and amazingly beautiful organisms.’

Peter Holland - University of Oxford

‘Leadbeater is the world’s foremost authority on choanoflagellates and has crafted a beautifully written and fascinating treatment of their biology, diversity, and potential to reveal the protozoan ancestry of animals. The reader’s journey starts in the mid-1800s, with Leadbeater providing a definitive history of the discoveries, missteps, controversies, personal rivalries and ultimate resolutions of important questions surrounding the early study of these important organisms. From there, Leadbeater provides an exhaustive accounting of what is currently known about the cell biology, physiology, ecology, and evolution of choanoflagellates, while also pointing out the many mysteries and outstanding questions that remain. The community of choanoflagellate researchers is growing, in large part due to the foundational research of Barry Leadbeater, and this book will be essential reading for all those interested in the lessons that choanoflagellates have to teach us about animal origins, microbial ecology, and the regulation of complex cellular ultrastructures.’

Nicole King - University of California, Berkeley

'A significant strength of the book is its comprehensive approach to all aspects of choanoflagellate biology combined with the author’s extensive experience with this group … an all-embracing state-of-the-art snapshot of choanoflagellate research … a valuable book for anyone interested in the diversity of eukaryotes and the biology of heterotrophic nanoflagellates and a must for anyone addressing any aspect of choanoflagellate biology.'

Jens Boenigk Source: Marine Biology Research

'Barry Leadbeater has given us the book [the choanoflagellates] deserve and every protistologist should have this in their personal library.'

John R. Dolan Source: Journal of Eukaryotic Microbiology

'This book is a beautiful, current compendium on choanoflagellates.'

Jack Cohen Source: The Biologist

'The Choanoflagellates is an excellent and authoritative book that covers all aspects of this group of protozoans and it will remain so for quite some time. It can be warmly recommended to protozoologists and to anyone interested in the origin of metazoans and in the evolution of multicellularity.'

Tom Fenchel Source: The Quarterly Review of Biology