Owing to their importance as primary producers of energy and nutrition, algae and cyanobacteria are found as symbiotic partners across diverse lineages of prokaryotic and eukaryotic kingdoms. Algal and Cyanobacteria Symbioses presents a compilation of recent, updated research in fields of diverse symbioses, including in marine, freshwater, and terrestrial habitats. It gives a comprehensive overview of algal and cyanobacteria symbioses, including reviews on their diversity and information on symbiotic specificity and stress tolerance. Also covered is a review of regulatory mechanisms in the communication between symbiotic partners. The highly interdisciplinary character of this book is demonstrated through the range of algae and cyanobacteria as energy-providing symbionts in organismal lineages which are discussed. It is a valuable source of knowledge for researchers, university lecturers, professors and students of biology and life sciences, specifically biochemistry, mycology, cell biology and plant-microbe interactions. Contents: Opening and General Aspects: Symbioses Involving Photosynthetic Organisms (John A Raven) Origin and Spread of Plastids by Endosymbiosis (Ugo Cenci, Daniel Moog and John M Archibald) Aerio-Terrestrial Symbioses: Symbioses of Lichen-Forming Fungi With Trentepohlialean Algae (Martin Grube, Lucia Muggia, Elisabeth Baloch, Christina Hametner and Elfriede Stocker-Wörgötter) The Lichen Photobiont Trebouxia: Towards and Appreciation of Species Diversity and Molecular Studies (Lucia Muggia, Fabio Candotto-Carniel and Martin Grube) Symbiotic Cyanobacteria in Lichens (Jouko Rikkinen) Symbioses of the Green Algal Genera Coccomyxa and Elliptochloris (Trebouxiophyceae, Chlorophyta) (Lydia Gustavs, Ulf Schiefelbein, Tatyana Darienko and Thomas Pröschold) Investigating Mechanisms of Algal Entry into Salamander Cells (Ryan Kerney, John Burns and Eunsoo Kim) Trade-Offs of Symbiotic Relationships between Aquatic Hosts and Algae in a Changing World (Daniel P Small and Cory D Bishop) Freshwater Symbioses: Cyanobacterial Endosymbionts of Paulinella Chromatophora Shed New Light on the Birth of Cellular Organelles (Andrzej Bodył, Jakub Cieśla, Paweł Mackiewicz and Przemysław Gagat) The Azolla–Anabaena–Bacteria Association: A Case of Symbiotic Abduction? (Francisco Carrapiço) Symbiosis Between Green Algae and Hydra (Yoshitaka Kobayakawa) Diatoms: By, with and as Endosymbionts (Patrick J Kociolek and Sarah E Hamsher) Symbiosis Between Testate Amoebae and Photosynthetic Organisms (Enrique Lara and Fatma Gomaa) Marine Symbioses: The Zooxanthellae–Hard-Coral Symbiosis (Noga Stambler) Embracing Complexity in Coral–Algal Symbioses (Danielle C Claar, Nicholas S Fabina, Hollie M Putnam, Ross Cunning, Emilia Sogin, Julia K Baum and Ruth D Gates) Microbial Diversity and Symbiotic Interactions with Macroalgae (Suhelen Egan, Vipra Kumar, Jadranka Nappi and Melissa Gardiner) Ascophyllum and Its Symbionts — A Complex Symbiotic Community on North Atlantic Shores (David J Garbary, Norah E Brown, Hillary J MacDonell and Jantina Toxopeus) Stress Tolerance and Secondary Metabolism: The Resistance of Lichen Photobionts to Extreme Abiotic Stressors on Earth, in Space and in Simulations (Andreas Sadowsky and Joachim Meeβen) Secondary Metabolites Produced by Cyanobacteria in Symbiotic Associations (Pavel Hrouzek) Final Remarks: Overview to Algae Symbioses (Joseph Seckbach) Readership: Researchers, university lecturers, professors and advanced students of biology and life sciences, specifically biochemistry, mycology, cell biology, botany, algae-specific anatomy and physiology, and plant-microbe interactions.