Book excerpt: Jellyfish are the often transparent, graceful creatures that float beautifully across the sea. Readers can try, but they're not going to find a brain in any jellyfish. They don't have spinal cords or bones either. This book explores how jellyfish survive and the parts they have that have allowed them to spread to oceans all over the world. With full-color pictures and amusing language, this book will engage the budding marine enthusiast and avid beach-goer.