Gr. 4-7. Collard has written about the wondrous underwater reef system many times, most recently in the picture book One Night in the Coral Reef (2005). In this entry in the Science Adventures series, he introduces a marine biologist and her research on fish that eat parasites living on other fish. Using lively anecdotes and clearly presented facts, Collard explains how scientists use established research and personal observations to pinpoint and pursue new directions of scientific inquiry. Closing chapters offer more examples of "cleaner-client" fish relationships and substantive information about reef endangerment, global warming, and ways that kids can help reduce greenhouse gases. Small but spectacular color photos show the jeweled, underwater worlds up close; a glossary and reading lists are appended.
