Rockwell and Halsey take on a topic of perennial interest in their latest collaboration, following a shark from birth to maturity while adding general comments about his teeth, skin, senses and skeleton, then closing with a spread of different sharks and challenging readers to identify this particular one (a blue shark). Halsey creates uncluttered marine scenes by placing cut-out painted shapes of flora and fauna against thickly brushed blue and green backdrops; Rockwell writes with typically low-key clarity (though a comment that the shark “usually stays below where the sunlight can reach” wants polishing), and closes with a recapitulative note. A guide to further resources wouldn’t have been amiss, but even without this makes an appealing prelude for Jim Arnosky’s All About Sharks (2003) and its swarm-mates. (Picture book/nonfiction. 6-8)