An animal with smooth, gray skin jumps from the ocean waves. Its tail waves up and down before it quickly dives again. Did you just see a dolphin? Or was it a porpoise? These animals look very similar, but they are different. Read this book to become an expert at telling these look-alikes apart. glossary, index, table of contents, websites.
General Note
Includes glossary.
Content Note
Pointed or round - Built to swim - Living in groups - Finding food - Who am I? - Fun facts.