Invertebrates, Second Edition, presents a modern survey of the 34 animal phyla (plus the Protista) and serves as both a college course text and a reference on invertebrate biology. Thorough and up-to-date in its coverage, it is organised around the themes of bauplans (body plans) and evolution (phylogenetics). Each phylum is organised in a standardised fashion, treating the systematics, bauplan (support and movement, feeding and digestion, circulation and gas exchange, excretion and osmoregulation, nervous system, reproduction and development), and phylogeny. Detailed classifications, phylogenetic trees, and references for all phyla are provided. Tables summarise each phylum's defining attributes. A modern treatment of the currently recognised groups of protists is also included. The text is accompanied by an abundance of detailed line drawings and - new to this edition - colour photographs.