Sea squirts and sponges are found in most seafloor habitats around the coasts of Britain and Ireland. Despite being the dominant life forms in many areas, these two groups of under-recorded marine animals are often confused with one another, and most divers and snorkellers can recognise and name very few species. In fact, around 500 species of Ascidiacea (sea squirts) and Porifera (sponges) have been described so far in British and Irish seas, corresponding to over 4% of the world's total. This book is recommended reading for anyone who wants to identify and discover more about these fascinating and diverse animals. Rather than relying on the characteristics of preserved specimens, this guide uses marine photography and detailed underwater observations to concentrate on in situ features, allowing you to record species without collecting them. Most sea squirts found in Britain and Ireland's shallow waters are included, together with the most easily recognised sponges. Whether you are a student, a diver, a rockpooler or simply an enthusiast, this is an essential companion. aAA AA Over 115 species described in detail, with in situ photographs to help with underwater recognition aAA AA Information on size, depth, habitat and distribution aAA AA Key distinguishing features and areas of confusion in identification highlighted aAA AA Details of body structure, life histories, digestive and reproductive processes aAA AA Information about predators, interactions between species, non-native and problem invasive species

A strikingly illustrated photographic identification guide to sea slugs in all their colourful variety Nudibranchs, or sea slugs, are a group of marine gastropod molluscs whose adults lack shells, an evolutionary loss that has led to a wide variety of body shapes, colours and colour patterns, making them popular with divers and underwater photographers. In this book, experienced nudibranch experts Bernard Picton and Christine Morrow provide an accessible and authoritative photographic identification guide for anyone interested in finding and identifying nudibranchs in the coastal waters of Britain, Ireland and Northwest Europe. Covers more than 195 species, each on its own two-page spread Includes in situ photos to aid finding nudibranchs under water and on the shore Features photos of nudibranchs’ distinctive spawn coils and studio photos showing detailed anatomy Presents key distinguishing features and essential information on size, habitat, diet and distribution

This is a truly interactive multimedia CD-ROM on the 337 species of sponges recorded in the coastal areas of the north-east Atlantic down to southern Portugal, found to a depth of 200 m. Each species is described and illustrated - the CD-ROM contains 1510 photographs and drawings - and can be accessed by two different identification keys. An illustrated glossary, a 'literature module' and the 'distribution module' are fully linked with the individual species, making searches easy. The 'higher taxa module' leads to information on the families, orders and classes of the sponges. As a bonus the CD-ROM features a 'who is who module' which contains portraits and biographic data on sponge systematicians.