This book covers in detail the development and use of the electric sense in fishes. Contents include coverage of taxonomy of the species involved, electric organs and electroreception, hormones and behaviour and the role of other sensory systems in conjunction with the electric sense. The book will be of great value to fish biologists, physiologists, evolutionary scientists, animal behaviourists and aquatic scientists.

Rare Earth Elements (REE) as well as tantalum and niobium are of tremendous importance because of their specific high-technology applications. The contributions gathered in this volume give an up-to-date survey on the mineralogy, primary ore deposits, prospecting, processing and applications of REE, Ta, and Nd, making this volume a useful handbook for practitioners and students. Finally, the comprehensive coverage of the fundamental aspects, especially as regards REE as tracers of geological phenomena, will prove extremely helpful.