6From the killer whale to the bottlenose dolphin, learn everything you ever wanted to know about marine mammals in this handy pocket-sized guide. Written by a natural history expert, this book provides a comprehensive introduction to all the families of marine mammals. Featuring well-loved creatures including whales, dolphins, porpoises, narwhals, otters, seals and even polar bears, it's the perfect introduction to life under the sea for young animal lovers. Get reading and then take your book out into the wild.