Richard C. Brusca is Director of Conservation and Research at the Arizona–Sonora Desert Museum, and also holds adjunct research positions at the University of Arizona and CIAD (Centro de Investigación en Alimentación y Desarrollo), Mexico. He earned a B.S. at California State Polytechnic University, an M.Sc. at California State University (Los Angeles), and a Ph.D. at the University of Arizona. The author of over 100 research publications, including six books, Dr. Brusca is a widely recognized invertebrate zoologist, marine biologist, and Sea of Cortez and Sonoran Desert naturalist. He is a Fellow in both the American Association for the Advancement of Science and the Linnean Society (London). Dr. Brusca has been the recipient of research grants from numerous organizations, including the National Science Foundation, the National Oceanic and Atmospheric Administration, and the National Geographic Society.

The late Gary J. Brusca was Professor Emeritus at Humboldt State University, retiring in 1998. Dr. Brusca earned his B.S. at California State Polytechnic University, his M.A. at the University of the Pacific, and his Ph.D. at the University of Southern California. For 35 years he focused his research on the ecology and systematics of hyperiid amphipods, also writing on a variety of other subjects in journals and textbooks. His main academic love, however, was teaching, for which he was recognized with numerous awards.

"Invertebrates" 2nd 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. It is organized around the themes of bauplans (body plans) and evolution (phylogenetics). Detailed classifications, phylogenetic trees, and references for all phyla are provided. The text is accompanied by detailed line drawings and - new to this edition - four-colour photographs. Other key changes from the 1st edition (1990) include: the incorporation of all the new developments in phylogenetics, developmental biology and molecular genetics; major changes at the highest levels among the invertebrates; three phyla that appeared in the original book Pentastomida, Pogonophora and Vestimentifera no longer exist, and an entire new phylum, Cycliophora, has been erected. Moreover, this edition discusses recent work in molecular systematics, and there is a large new section on "Kingdom Protista" (replacing "Protozoa") containing new contemporary views of these organisms (arranged in 17 phyla).