Just received the new book on the genus Liguus by González et al. A contribution that put some weight (3.4 kg to be precise) and size (4 cm on your bookshelves) to the subject.
Leafing through the book with much attention I noticed the following which will also form my review:
This book is the third book on land snails of the first author and the second one which is confined to one genus, the previous books entirely confined to Cuban species. For this book on the Orthalicidae tree snail genus Liguus distributed from Hispaniola to Florida, Adrián González joined forces with Pete Krull and Luiz Lajonchere; the latter has published on this genus before. The book has 10 chapters on historical studies, collections, palaeogeography, taxonomy of the Cuban, Floridan respectively Hispaniolan (sub)species and colour forms, biology and ecology, and finally conservation issues. On the enclosed CD appendices to several chapters and the bibliography is found. There are 161 (unnumbered) plates of Liguus colour forms and hundreds of colour photos of live snails.
Liguus tree snails have catched the eye of shell collectors and artists since the beginning of the 17th century till today. They have many different colour patterns and hybridisation between several colour forms does occur, as well as gigantism and dwarfism. The result is an astonishing number of names for them, either officially or unofficially introduced which can be found in both museum and private collections. The book starts with a disclaimer “not deemed to be valid for the purpose of formal taxonomic nomenclature”. Although this seems a justified action, it is perhaps also a too modest action once one realises that 161 names are available for Liguus taxa (Appendix 11), plus several unofficial varieties and a bunch of manuscript names. The authors have neatly streamlined this horrendous chaos into five species (including Liguus flamellus and L. blainianus; if the biological species concept is applied only three remain: Liguus fasciatus, L. virgineus, L. vittatus). The core of the book is thus the two taxonomic parts (Chapters 4 and 5: pp. 63-279 for Cuban taxa, and Chapters 7 and 8: pp. 304-421 for respectively Floridan and Hispaniolan taxa), in which the species, their subspecies and lineages are treated by giving for each the original publication, the type locality, the description, their distribution and concluded by remarks. Especially the many Cuban taxa have not always been properly figured, and the authors have done much effort to search for these specimens and photograph them to modern standards. Almost each is beautifully illustrated on the plates which show 24 shells each, grouped in four rows. On several pages (pp. 73-74, 132, 198, 265, 304, 345, 411-412) maps are given that help to understand how the subspecies and lineages are distributed. Several interspersed plates illustrate the living specimens of one or more morphs.
The introductory chapters 2 and 3 present historical data, including iconography and collecting information. Many historical photos are included, and I spotted some that I have not seen before. A brief chapter 4 presents the geological background needed to understand current distribution. Chapter 6 bridges both taxonomical parts and treats a question that several scientists have been struggling with: the connection between Cuban and Florida Liguus taxa. Although many unanswered questions remain, the authors suggest that Liguus baby shells were carried on the wind of hurricanes from Cuba to Florida. They also suggested that these were relatively recent (geologically speaking) events. Of course, these and other questions needs further confirmation and future molecular studies may hopefully at least partially solve them. The final two chapters (9 and 10) are devoted to the biology, ecology and conservation of these snails. In the first one data are compiled among others about life span, population density, predation, host plants and trees. The last chapter treats habitat destruction, introduced predators, protection regulations and laws, protected areas and some suggestions for further conservation.
The appendices have been stored on an accompanying CD, which when I inserted it in my system appeared to contain one rar-file. After decompressing a pdf-file of similar size was shown, which raises the question why it was compressed anyway. The file has several appendices showing supplementary information, e.g., historical collecting field trips by U.S.A. malacologists to Cuba, the dispute of the holotype and ‘type’ locality of Liguus fasciatus, collectors mentioned on labels of Cuban Liguus shells, manuscript names and their current status, a list of available names, and additional ecological, anatomical, and conservation data. Together these form the first 58 pages. The final 30 pages are bibliographical references, a huge list in small print.
The authors justified write in the introduction “there has never been of book about Liguus that included every named form from the Cuban archipelago, peninsular Florida, and the island of Hispaniola”. In fact they have made a revision of the genus which is easily readable for non-scientists and, together with the many high-quality photographs, have done an amazing job. Are there no critical remarks to be made? Yes, but only a few. The plates are unnumbered and therefore no link is made between the text and the illustrations. Also no index has been provided which would have helped to locate easily both the scientific names and person names in the book and appendices. Both points make the book less useful as a reference work. While the authors say “word can fly but writings remain” (p. 497), they would have done better to replace the CD (soon outdated) with a more permanent alternative; the information in the appendices is too important to have it not available.
My overall impression is that this work will be seen as a hallmark for the decades to come. The book will serve both amateurs and professionals and should not be lacking in any relevant library.
González-Guillén, A., Krull, F. & Lajonchere-Ponce de Leon, L.A., 2018. Liguus. The flamboyant tree snails: 1-498 + 88 pages on accompanying CD. F. Krull, 132 1st ST. E #105, Tierra Verde, FL 33715, U.S.A. ISBN 978 0 9847140 5 6. Price US $ 189.90 net (hardcover).