Book Reviews

Guides to the Identification of the Microinvertebrates of the Continental Waters of the World Volume 14: Copepoda: Cyclopoida Genera Paracyclops, Ochridacyclops and Key to the Eucyclopinae

Süphan Karaytug
224 pp., 1999
Backhuys Publishers, Leiden, The Netherlands
ISBN 90-5782-030-7
Softbound. Price $70.00 US/Dutch Guilders 140.00

The science of description and discrimination of species of freshwater copepod crustaceans has passed through three general phases. In the early, exploratory phase, specialists such as Schmeil (1892) and Gurney (1931-1933) described nearly the entire body of the animal, including fine details of the mouthparts. In a subsequent reductive phase, taxonomists adopted a standard format for differential descriptions, involving morphological and morphometric comparisons of only those structures thought to be most taxonomically significant (e.g., Kiefer, 1960; Dussart, 1984). It is only during the past 20 years or so that taxonomists have begun to recognize that more than one taxon may have become subsumed under such general descriptions, and have begun to apply a combination of tools including examination of minute morphological detail, analysis of variation, genetic characters including allozymes and DNA/RNA, crossbreeding, and a healthy skepticism of previous work in their re-analyses. This evolution has led to considerable confusion and frustration, as it has become more and more difficult to assign specimens to a particular taxon with any confidence.

Fortunately there are still talented individuals who have taken up the challenge of revising one group after another, even in view of the notoriously problematic prospects for employment and funding for taxonomic work. Süphan Karaytug succeeded in revising most of the ubiquitous genus Paracyclops plus the small allied genus Ochridacyclops, and we now enjoy an abridged version of his several years’ labours in Volume 14 of the “Guides” series. Introductory sections firmly ground interested readers in the history of the systematics of the family Cyclopidae, briefly explain methods, and explain the specialized terminology. A succinct key to the subfamily Eucyclopinae is followed by efficient reviews of the composition, distribution, zoogeography, and biology of members of Paracyclops and Ochridacyclops. There are keys to adult females and males of Paracyclops, and to females of Ochridacyclops (the author had no material of males of the latter genus available). These keys permit the user to arrive at a species name relatively easily, with only a few glitches (for instance, couplet 12 in the key to females refers to “three setae” when apparently “three inner setae” is meant). However, the great value of the book is in the copious and fully detailed illustrations of most species (those for which Karaytug was able to examine actual specimens). The written descriptions indicate the best discriminative characters and their variability, and the extensive evaluations of the history of each taxon alert the user to potential problems and help avoid at least some of the pitfalls.

It is educational to compare Karaytug’s own illustrations with the reproductions of earlier figures, which provide a good indication of how much remains to be done, even in this not particularly species-rich group. At least this book will help non-taxonomists to determine in most cases whether they are working with a named species, and what that species is, which is all we can ask of a guide. The price is rather high, but is a consequence of the copious illustrations and text, well printed on resistant paper.

References

Dussart, B.H. 1984. Some Crustacea Copepoda from Venezuela. Hydrobiologia 113: 25-67.

Gurney, R. 1931-1933. British Fresh-water Copepoda. Vols. I-III. The Ray Society, London.

Kiefer, F. 1960. Neue Cyclopoida Gnathostoma (Crust. Cop.) von den Inseln Madagaskar und Reunion. Zoologischer Anzeiger 165(5-6): 226-231.

Schmeil, O. 1892. Deutschlands Freilebende Süsswasser-Copepoden. I. Cyclopidae. Bibliotheca Zoologica 4(11)(1): 1-192 + plates 1-8.

Janet W. Reid
Smithsonian Institution
Washington, D.C.

Pêche du sambaza au filet maillant dans le lac Kivu Rapport final du projet ONG/219/92/Zaïre

B. Kaningini, J. Cl. Micha, J. Vandenhaute, J.-P. Platteau, H. Watongoka, C. Mélard, M. K. Wilondja, and M. Isumbisho
188 pp., 1999
Presses universitaires de Namur
Rampart de la Vierge, 8, B-5000 Namur, Belgium
ISBN 2-87037-287-6
Price - Belgian Francs 1000/Euros 24.79

Lake Kivu has a depauperate fish fauna of about 24 indigenous species, 15 of them being endemic Haplochromis species. Fish were of little importance to the local people until the introduction of the clupeid Limnothrissa miodon (“Sambaza”) from Lake Tanganyika. These sardines are captured at night in lift-nets, using light attraction but this book describes an alternative approach, using small-meshed (10-11 mm) gill nets. It is of some interest to people involved in African fisheries although the situation and methods described in it are unique to Lake Kivu. The report gives limnological data – some old and some contemporary – that would be of interest to anyone unfamiliar with the lake. Although treated rather superficially, these data still demonstrate how little is known of Kivu’s limnology compared to that of other Great Lakes. This is followed by an account of the Sambaza introduction, the development of the fishery, and the rationale and history of this project.

The biology of Limnothrissa, is discussed in some detail but the indigenous haplochromines (about 80% of the catch) are dealt with cursorily. They are small fishes (< 12.5 cm) largely restricted to littoral waters – a restricted habitat in Lake Kivu where most shores are steep – and probably not very abundant. I couldn’t help wondering what the awesome destructive power of small-meshed monofilament gillnets would do to these fishes. Elsewhere in Africa, Limnothrissa can withstand high levels of exploitation, but the decline in the catch per unit effort from 1.8 to 0.43 kg/100 m2 between 1992 and 1998 described here suggests that local depletion had occurred, which could affect its recruitment since it breeds inshore. The impact of these nets on the other species was unclear but I would expect it to be even more severe.

The book concludes with a discussion of the socio-economic aspects of the project and one has to ask if it is sustainable without continuing donor assistance. This and other issues could have been discussed in greater depth but the authors worked in an atmosphere of general insecurity following the Rwandan massacres. The fact that they produced a report at all is most commendable.

Brian Marshall
University of Zimbabwe
Harare

Peixes do Pantanal Manual de Identificacao

H.A. Britski, Z.K. de S. de Silimon & B.S. Lopes
184 pp., 1999
Publisher: Embrapa-Serviço de Produç|o de Informação, SAIN Parque Rural, Final Av. W3N, Caixa Postal 040315, 70770-901 Brasilia, DF, Brazil
In Portuguese
ISBN 85-7383-053-0
Price - R$70.00 (approximately $36.85 US)

A recent paper on South American freshwater fishes expressed the need for identification manuals - very difficult to prepare as the fish fauna is so rich and complex and so much basic taxonomic work is needed. Identification keys are now available for the fishes of the Pantanal Mato-Grosso waters in West central Brazil in this beautifully produced book with its lavish colour plates of the fishes. An area of great beauty, as shown by the colour photographs, this vast (~ 150,000 km2) Pantanal waterland is much visited for the spectacular flocks of birds which come here as the seasonal floods subside. Initial chapters describe the characteristics of the area and the history of taxonomic studies of its fishes, of which some 263 species are now known, predominently Characiformes and Siluriformes, with cichlids, gymnotiform electric fishes, cyprinodontoids and representatives of other groups including the lungfish Lepidosiren and stingrays. Many specialists have collaborated in the preparation of this book, which has a useful bibliography and drawings to assist with identifications. It is designed for laboratory rather than field use, with a heavy binding and large format (33 X 26 cm).

Rosemary H. Lowe-McConnell
United Kingdom

Die Haplopoda und Cladocera (ohne Bosminidae) Mitteleuropas

Dietrich Flössner
XII + 428 pp., 2000
Backhuys Publishers, Leiden
ISBN 90-5782-057-9
Hardbound (Text in German)
Dutch Guilders 264.00/$132.00 US

If you can read German and you are interested in the Cladocera, you will wish to have this book. It is an update of Flössner’s 1972 Branchiopoda book in Tierwelt Deutschlands (but not including the so-called “big branchiopods” and, as stated in the title, the bosminids), which I have used as a vademecum for many years. Only in the 1980s, when the winds of change started shaking the old beliefs about cladocerans, did I turn to other, more recent sources.

The “new Flössner” provides a snapshot in time of the current taxonomic situation within a group of organisms (actually representing four distinct orders) which, today more than ever before, is in a state of flux. What appears fairly established today may be totally obsolete tomorrow. Clearly, Flössner has made a commendable effort to bring his treatment of the genus Daphnia up to date with modern (molecular) standards, and provides ample illustrations of most species, as well as a key to hybrids. However, things in this domain move so quickly that on page 380 a number of amendments to statements on species made elsewhere had to be inserted. It is to be expected that such changes will continue for a while.

The treatment of the non-daphniids has remained rather traditional, and Flössner seems reluctant to adopt Geoffrey Fryer’s four-order system, widely accepted by most authors. It is particularly regrettable that Ilyocryptiinae are still treated as a subfamily (they clearly are a family!) of the Macrothricidae, with which they have little in common! The recent subdivision of the anomopod cladocerans in two main groups, the radopods and the non-radopods, has not yet made it to this text either (although the reference to it is cited in the “additional references”). Likewise, the resurrection of the chydorid genus Paralona (to contain Chydorus piger) is referenced, but not implemented in the text.

Flösser acknowledges D.G. Frey as the great innovator of cladoceran taxonomy. However, we are way past this stage now. The new names in town are Kotov, Sinev, Elias, Silva-Briano, Brancelj, and Hudec!

Although I will use this book, I wonder what geographic area it applies to: does Central Europe extend to France (the home of Alona phreatica) and to Italy (home to several endemic Alona species), or not? This is said nowhere in the text...

H. Dumont
University of Ghent
Belgium

Water Pollution: Methods and criteria to rank, model and remediate chemical threats to aquatic ecosystems

Lars Håkanson
277 pp., 1999, Backhuys Publishers, Leiden
IBSN 90-5782-024-2
Dutch Guilders 180.00/ US $100.00 (hardbound)

This book addresses the empirical and dynamic modelling of water pollution and focuses on three examples: acidification, eutrophication and contamination by mercury and radiocesium. The data are drawn from Swedish lakes and coastal areas of the Baltic, where the author has a great deal of first-hand experience since the 1970s.

The book is organized into seven chapters including references and appendices that provide the details of the models with equations and suppositions. Chapter One outlines the Potential Ecological Risk (PER) approach for ranking chemical threats at the ecosystem level. The PER includes three basic indices: 1) the effect variable or the degree of ecosystem level effects, 2) the areal or geographic extent of the problem; and, 3) the duration of the problem. Interestingly, Håkanson concludes that acidification remains the largest chemical threat to Swedish ecosystems overall, followed by coastal and lake eutrophication, mercury contamination and finally radiocesium contamination.

Chapter 2 introduces the basic elements of Effect Load Sensitivity (ELS) models and is more technical in explaining the statistical considerations for predictive success. Coastal eutrophication is modelled here with “target effect variables” such as oxygen saturation of deep waters, “load variables” such as nutrients and “sensitivity variables” related to coastal morphometry. Chapter 3 addresses the difference between traditional mass-balance models (or dynamical models) and statistical empirical models and how they can be linked. The dynamic radiocesium and mercury models presented could serve as a template for most chemical substances in aquatic ecosystems. As Håkanson states, it is ironic that the Chernobyl accident has been perhaps the “most important factor behind the revolution in predictive ecosystem modelling … the decrease in the uncertainty factor from 10 to 0.25- 0.5”. How these models can be used to assess various remedial measures is illustrated in the last chapter.

For the most part the book is quite readable with informative figures and tables. However, it is not particularly well edited as there are more than the odd typographical and referencing mistakes. There is some overlap in content between this book and the text Predictive Limnology that Håkanson co-authored with the late Rob Peters in 1995. But in Water Pollution, Håkanson also tackles coastal marine systems with the same elegant and ultimately successful approach. Water Pollution is probably a better choice as a graduate textbook than the lengthier and more expensive Predictive Limnology. For teaching purposes, it would be most useful if the author developed a website where some of the models could be accessed directly.

In summary, this book provides clear directions for the development of practical ecosystem models. I highly recommend this book to limnologists, coastal oceanographers, environmental engineers and ecotoxicologists alike.

Frances Pick
University of Ottawa
Canada