A Field Guide to the Nudibranchs of the British Isles

This book is intended as a photographic guide for divers and underwater photographers, and in illustrating all British species, including a few unnamed ones, it achieves its aim. There is a short introduction, followed by a strong section on food and feeding. This lists all prey/predator relationships known to date for British species, tabulated with the nudibranchs taxonomically arranged and with sub-order diagnoses. Another table lists prey groups as the main heading, and gives the nudibranchs feeding on them worldwide. A brief chapter discusses reproduction, and there are useful sections on how to look for nudibranchs, recording schemes, conservation, and collecting/preservation techniques. The section on anatomy with tables and diagrams of rhinophore types is useful, as is the glossary of technical terms for the non-specialists. The glossary of Latin names is fun and may help some remember the scientific names!

The bulk of the book is given to species descriptions, with text on the left and a photograph/illustration on the facing page. The descriptions are brief, highlighting diagnostic features, average and/or maximum sizes (although a number of species are missing size data). The second paragraph describes prey species and egg masses, while the third covers distribution around the British Isles and Europe. Many descriptions have an additional paragraph discussing similar species. Each species has two or three bullet points of key characteristics.

The list of 'Books on nudibranchs and other sea slugs' covers so many of the colour guides available to date that it is difficult to understand why Schmeckel & Portmann (1982), Cattaneo-Vietti, Chemello, & Giannuzzi-Savelli (1990), and Wells & Bryce (1993) are omitted (and the updated reprint of Behrens (1991)). This section is followed by half a dozen lines covering a few journals which publish opisthobranch research. The selection of 'authors of taxonomic papers . . .' is puzzling, and one wonders at its purpose. A simple index, including taxonomic and technical terms, concludes the book.

With all the recent photographic publications of sea slugs from various geographical regions, it was inevitable that one would soon appear on the British fauna. Photographic guides are useful in supplementing records of species, but cannot replace accurate, detailed drawings. The latter, especially in colour, have the advantage of showing more anatomical and colour detail, which is of value for identification purposes. However, Bernard Picton's expertise in identifying these creatures compensates for the possible queries in identification. However, the photographs on p. 90 of Janolus hyalinus and Proctonotus mucroniferous could easily be of the same species, whereas drawings could have emphasized the difference more clearly. The guide is based on the senior author's many years of working on the British marine sublittoral, and as such is a welcome addition to any library. Only nudibranchs are covered in the book, and all but a few are illustrated with colour photographs of living, crawling animals, often in their natural habitat or on their food, sometimes with spawn. It is a shame that there are not more pictures of spawn: Picton & Morrow state in their introduction that often the first sign of a nudibranch is its spawn, which they describe for the majority of species.

There are some errors, mostly minor irritations such as spelling errors, Latin with a small 'l'; flabellinids, aeolids, sagartiids with capital first letters; Linnaeus sometimes spelt out, sometimes abbreviated; etc. Another query is why Eubranchus sp. A and sp. B are placed with the Eubranchus in the main systematic treatment, but Eubranchus sp. C is not. The same applies for the last four species with photographic records (two Doto spp., Cadlina sp.,Janolus sp.), which would have been more usefully placed in their respective genera.

Overall, the book is to be highly recommended, with lovely photographs and useful ecological details of use to divers, marine biologists, and specialists.