Book excerpt: This book deals with the ecology of rivers and streams in the Oriental Region, and describes the composition of their unique fauna - especially the diverse array of animals which live on and among the bottom sediments. Dichotomous keys are provided as an aid to the identification of these animals, and the book is illustrated by over 100 pages of line drawings and maps. Special emphasis is given to the impact of human activities on streams and rivers, and the book concludes with a discussion of conservation and management options for these endangered habitats.