The importance of toxins and other phanuacologically active com pounds obtained from marine animals cannot be emphasized enough. The use of these chemicals for defense or attack of other life fonus are of interest in themselves; however, they are of great importance in our understanding of their mechanisms of action in view of possible application in the defense of man (no doubt a predator) and in biol ogy and medicine. The toxin of the flat fish Pardachirus presented in some of the papers of this book is an example of a defense mechanism based on secretion of a toxin that could possibly be extended to being used to defend man himself from sharks, the marine predators par ex cellence. August, 1984 J. ZADUNAISKY Preface The study of toxins, drugs, and pollutants in the marine environment, and their impact on human life existed already in Babylon and Assyria, Egypt, Persia, India, China, Japan, Greece, Rome and South America. Nevertheless, less is known about ethnic marine biology than about ethnobotany. Only recently however, have active biotoxins been used as molecular probes in neuropharmacology, offering intriguing new insights into nervous activity and muscular functions. It is clear from the presentations at this meeting that much remains to be done, and certainly new, more pharmacologically oriented find ings lie ahead."

Advances in Compararative and Environmental Physiology helps biologists, physiologists, and biochemists keep track of the extensive literature in the field. Providing comprehensive, integrated reviews and sound, critical, and provocative summaries, this series is a "must" for all active researchers in environmental and comparative physiology. Cellular volume and osmolality in animals is a well studied topic and this specific volume in the series provides the reader with a thorough grounding in this area of physiology. Consisting of two parts, the text discusses osmolality and volume control in terms of both inorganic and organic ions which as a result gives an excellent overview to those working and interested in this field.

The idea of Professors Bolis and Gilles to gather together for a 3 days' meeting in the splendid environment of Crans-Montana in Switzerland a limited number of people around the subject of calcium and calcium bind ing proteins seemed at first particularly attractive, and when they asked me to take charge of the scientific organization of the symposium, I accepted with enthusiasm. It rapidly became clear that the major problem would be the selection of the topics, since it was impossible to cover completely and in depth such a broad and dynamic area of research. In our view, one imperative was to associate as intimately as possible the structural and the functional aspects of the areas covered. Apart from one whole day focused on the fascinating roles played by calmodulin in cellular activities, the other sessions were devoted to calmodulin-related calcium binding proteins in muscle and non muscle tissues and to some selected biological systems such as mitochondria, secretory cells or sarcoplasmic reticulum in which calcium also plays a crucial role. The presentations were made by leading investigators in their field. Some of them do not, however, appear in the present volume, for which there are two reasons: first, some of the contributions were somewhat outside the scope of the book; second, three speakers, for valid reasons, simply found no opportunity to write a manuscript in the allotted time.

Presenting an analysis of the water relationships of the major groups of organisms: fungi, plants and animals, the text examines water stress at all levels of biological organization. Topics covered include: 1) organic osmotic agents: their distributions, modes of action, and mechanisms of regulation; 2) desiccation stress; mechanisms for preserving cellu lar integrity under conditions of low cellular water activity; 3) water stress and water compartmentation in plants; and 4) freezing stress: the prevention and regulation of ice formation in biological fluids, and mechanisms for overcoming the damaging effects of low temperatures on cellular integrity. Common adaptive strategies in diverse organisms are emphasized, as well as the fundamental physical-chemical properties of aqueous solutions that establish the nature of the interactions among water, low molecular weight solutes and macromolecules.

When I was asked to organize this symposium on marine producti vity, it made me reflect on what aspects of this subject would be stimulating to a heterogeneous group of laboratory-oriented physiolo gists and biochemists. In recent years there have been several books which discusses the methodology commonly used in primary production studies and described the magnitude of photosynthetic CO reduction 2 in various areas of the world's oceans. I therefore decided to dis pense with these conventional aspects of primary production and invite researchers to speak on a variety of problems relating the abundance and activity of phytoplankton to environmental conditions. The lectures I invited were thus quite diverse in character, but all were related either to factors affecting the rate of photosynthesis or to the fate of reduced carbon as it passes through the microbial food web. In addition to these talks the participants benefited from a number of shorter presentations and poster sessions which dealt with production and cycling of organic carbon in the marine environment. February 1984 Osmund HOLM-HANSEN CONTENTS 1. Factors Governing Pelagic Production in Polar Oceans E. SAKSHAUG and O. HOLM-HANSEN *. **. ****. . . . . . *. ***. . ****. *. **** 1 2. Productivity of Antarctic Waters. A Reappraisal S. Z. EL-SAYED *. . . ********. . ***. *. *********. ***. *. *. . . . *. . . . *. 19 3. A Thermodynamic Description of Phytoplancton Growth D. A. KIEFER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4. Mechanisms of Organic Matter Utilization by Marine Bacterio plankton 45 F. AZAM and J. W.

This 1978 volume contains papers from contributors to the Third International Conference on Comparative physiology. The Conference selected particular areas for examination. In the first section of this volume the problems of how animals can take up water vapour from the atmosphere are considered as well as advances in studies of how water movements across epithelia are generated by solute movements. The second section deals with how a wide variety of animals, both invertebrate and vertebrate, living under stress in ionically unbalanced environments cope with the unusual difficulties of ionic regulation. In the final section biologists and physicists examine the role of fluid mechanics in biology. Both the theoretical basis of the hydrodynamics and aerodynamics and the biological investigations on the variety of fluid flows encountered inside and around organisms are presented.