Book excerpt: This book is a sequel on the topics of photoreception and phototransduction covered by Volume I of the series (Biophysics of Photoreception: Molecular and Phototransductive Events), adding the analysis of two other modalities of sensory reception and transduction — the chemical and mechanical ones, which are phylogenetically older. This characterization results not in a succession of three different and uncorrelated moments, but in a fruitful confrontation between experts which usually act separately and in an integration between various particular knowledges. This approach highlights the basic strategies common to different sensory modalities and specializations, as well as the ecological adaptations of each of them.