highly useful basic book of biological production in fresh waters for hydrobiologists, aquaculturists and for all who are working or interested in water industry, water protection and the utilization of natural water resources. The title of the book, however, is The Functioning of Freshwater Ecosystems, and the function of all ecosystems is realized in energy flow and in mineral cycling. Actually the latter is included but very briefly in this book. The functioning and the practical operation of protein producing, freshwater agroecosystems (for example, fish ponds) parallel with intensification is highly dependent on the oxygen and nitrogen cycles. Similarly, progress in water industry and in water environmental protection is limited by surplusses of phosphorus and nitrogen and by shortage of oxygen. Promoted by these basic demands and by some important discoveries in methodology, a rapid revolutionary progress has taken place, especially in the research field of the nitrogen cycles. However, this occurred mainly after 1974. Hence, understandably, for instance it is stated in this book “It does seem unlikely that nitrogen fixation can form a significant contribution in general to the nitrogen cycle”. Today many papers demonstrate the very reverse of this statement. But quantitative data are proliferating very rapidly on many other pathways such as denitrification and nitrification of the nitrogen cycle. This extremely valuable book would therefore be more correctly entitled “Energy Flow in Freshwater Ecosystems”. J. OLiH (Szarvas, Hungary)
FISH FARMING HANDBOOK
Fish Farming Handbook. E.E. Brown and J.B. Gratzek. Avi Publishing Co., U.S.A., 1980. 392 pp., US $19.00 (U.S.A. and Canada), US $21.00 (elsewhere), ISBN 0-87055-341-O. This handbook .represents a collaborative effort between the principal authors and selected contributors, each an established authority in his particular field. It presents a solid body of information on the culture of a number of important freshwater finfishes as practiced in the United States. Species covered include channel catfish, trout, salmon, eel, two species of tilapia, big mouth buffalo, goldfish, as well as many bait and ornamental (tropical) species. Its only references to marine species are brief discussions of sea ranching for salmon, and the production of pan-sized salmon in floating pens. The quality of writing is generally good, and will be understandable to laymen. It is organized into eight chapters: Introduction, Environmental Factors, Types of Culturing Facilities, Maintenance and Improvement of Ponds, Methods, Nutrition and Feeding, Common Fish Diseases and Their Control, and Processing and Marketing.
The introduction (11 pages) presents brief descriptions of the relative size and importance of the various types of cultures, some of the existing constraints, and the areas where each is practiced. The chapter on Environmental Factors (8 pages) stresses the importance of water quality in fish production. It gives special attention to oxygen, temperature, photoperiod, and toxic materials, and how fish are affected, and how they respond to variations in these important environmental parameters. The chapter on Types of Culturing Facilities (16 pages) describes the facilities needed for various types of cultures and provides a practical discussion of the construction and operation, as well as the advantages and limitations, of each. The chapter on Maintenance and Improvement of Ponds (28 pages) discusses methods for pond fertilization, for maintaining desirable levels of oxygen, for the control of pond pH, and for the control of aquatic weeds. It seemed notable that almost 12 pages are devoted to discussions of some 20 herbicides, but less than one page is devoted to control by biological means. Some will view this as a deficiency because grass carp are now widely and successfully used for this purpose, and the hybrid of the grass and bighead carps may be even more extensively used in the future. Quite appropriately, the longest chapter (133 pages) is that on methods, which provides detailed instructions for culturing the more important species treated. The section on channel catfish moves the reader step by step from the selection, care and pairing of broodstock, through spawning and rearing, to the harvesting of the final products. The section for trout is equally detailed, and should be helpful regarding the special equipment required for trout culture. Techniques for producing goldfish and the more important bait fishes are almost equally elaborate, and aquarists will be pleased with the extensive treatment given ornamental fish. This last deals with all important aspects of culture, both indoors and outdoors, for most important species of both livebearers and egglayers. Nutrition and Feeding (26 pages) are given excellent coverage through orderly discussions of nutrient requirements (protein, energy, vitamins, etc.), diet formulations and processing, and feeding practices, with attention to the special needs of individual species. The chapter on Common Fish Diseases and Their Control (100 pages) is also strong. It emphasizes the importance of prevention through good water quality, absence of stress, and proper nutrition. It describes most of the common disease agents, both infectious (protozoan, bacterial, fungal or viral), and noninfectious (nutritional deficiencies, intoxications, low oxygen levels, etc.), as well as most of the common, larger parasites (trematodes, cestodes, nematodes, etc.). This chapter is particularly well illustrated. Methods of diagnosis, as well as directions for sending fish for diagnostic services, are provided, along with a list of treatments with detailed instructions for their administration. The final chapter, Processing and Marketing (24 pages), describes existing
processing and marketing systems, and provides helpful suggestions for those just entering the market. Each species, or type of product, is discussed separately . This handbook is highly readable, well organized, well illustrated, and thoroughly indexed. Its principal value is that it brings together a great many items of information previously available only in scattered sources. It will be of particular value to those seeking one primary source of information on the culture of such traditional species as channel catfish, trout, goldfish, bait fishes, and ornamental species. It will be unrewarding for those seeking information on such relatively new areas of aquaculture as closed or recirculated systems, the culture of tilapia, Chinese carps, or other exotic species, on the biological control of aquatic weeds, on water quality control with herbivorous fishes, on the recycling of organic wastes, or the use of waste heat. H. BUCK
(Salem, IL, U.S.A.)
(Industrial Fish Production). W. Steffens (Editor). Institut fiir Binnenfisherei, Berlin-Friedrichshagen, VEB Deutscher Landwirtschaftsverlag Berlin, 376 pp. illus., paperback, order number 558 913 8, Price M 12.25.
The book edited by Werner Steffens gives a concise review, in the German language, of freshwater fish culture in the German Democratic Republic. It is the co-production of 12 authors who cover in 14 chapters the several aspects of culture, fish diseases, technology, management, fishing gear and marketing of freshwater species. Freshwater fish production rose in the GDR from 1950 to 1975 by 272% (17 432 t). The most important reared fish are carp (11 863 t) and trout (1 947 t). However, eel, grass carp and silver carp also seem to have good prospects. Also reviewed are salmon, coregonids, pike, pikeperch, European catfish and sturgeon. The book is aimed at students of various fishery courses as well as of universities. However, a wider audience interested in fish culture will read it with profit. It is striking that no references are given, not even for further reading, a bad omission in a text-book for students. The price is very attractive and for nobody a hindrance to obtain such an amount of information. Hence one should not be too critical of the outer appearance of the book. S.J. de GROOT