This volume, the first in the series ‘Aquatic Biodiversity in Latin America’ published by Pensoft, is an updated edition of Thatcher (1991). In 11 chapters it provides an overview of the metazoan parasites and some protistan parasites of Amazon fishes. Each chapter includes short explanatory sections entitled ‘definition and morphology’, ‘lifecycle and transmission’, ‘pathology’, ‘prevention and treatment’ and ‘collection and study methods’. Then come keys to the genera in English and Spanish (not Portuguese) and a checklist of the species with the generic diagnoses. Associated with each chapter there are copious and usually excellent illustrations and a reference list.
The first chapter is a general introduction and the second headed ‘Protozoa and Ciliophora’ includes the Myxosporida (Myxozoa), now widely recognized as a metazoan group (Canning and Okamura, 2004). The chapter is rather small and indicates that these groups have been particularly poorly studied.
The third to eleventh chapters cover, in order, the Monogenea, Trematoda, Cestoda, Nematoda, Acanthocephala, Copepoda, Branchiura, Isopoda and, finally, the Hirudinea, Pentastomida and unidentified pathogens. An ‘addendum’ supplies a host-parasite list.
The Monogenea are considered ‘perhaps the least known’ group, but with 308 species and 70 genera listed, this seems unlikely, particularly in comparison with the subjects of the second chapter. The longest chapter is that on the trematodes, and is notable for the high diversity of fish amphistomes, so rare elsewhere, and the extraordinary shapes and ornamentation they exhibit. The cestode chapter includes those tetraphyllideans and trypanorhynchs found in the freshwater elasmobranches of the Amazon basin.
The diversity described is astounding. It would have been interesting if this could have been put in a more general context, particularly in respect of the state of the study of Amazon fish parasites. For example, we have no information on how many fish species occur in the Amazon, what proportion has been examined for parasites and what collection biases (e.g. geographical) there may have been.
It is also a shame the author has not taken this opportunity to update the systematics and nomenclature of some of the groups. Why, for example, use Monogenoidea (with its superfamily ending) for the much more widely used Monogenea? At one point the group name Cotyloda (p. 213) replaces the better known Cestodaria, although it would probably be better to use neither as current evidence suggests that this ‘group’ is polyphyletic (Xylander, 2001).
The production value of the book is good, with just a few misspellings, e.g. pl VIII is headed ‘Myxoxporida’, and other errors, e.g. figure labels 4–20 and 4–21 appear to be transposed.
Nevertheless, this is an attractive and useful volume, with many illustrations, including some excellent ones in colour, showing the amazing diversity of parasitic protistans and metazoans in the fishes of one river basin.
