This volume explores emerging approaches and methods inspired by recent research using ctenophores or placozoans, facilitating the study of these enigmatic species and ancient animal lineages. Practical protocols are integrated with introductory chapters about general biology, summarizing the diversity, evolution, genomics, development, and neurobiology of these organisms. Special chapters outline strategies and applications for culturing, microscopy, physiology, electrical synapses, and bioluminescence, molecular and single-cell biology, transcription factors, as well as gene and protein expression analyses. The book also contains bioinformatics and computational chapters covering peptidomics and epigenomics. Written for the highly successful series, chapters include detailed implementation advice that leads to dependable results in the laboratory. Authoritative and practical, is an ideal resource for comparative and experimental biologists and interdisciplinary scientists aiming to decipher fundamental principles of animal organization, origin, and the evolution of biological complexity in general, opening novel avenues for future synthetic biology research.