Jellyfish are mysterious creatures, luminously beautiful with remarkably varied life cycles. These simple, ancient animals are found in every ocean at every depth, and have lived on Earth for at least the last 500 million years. Ominously, they are also increasing in number as they adapt well to marine environmental degradation. Jellyfish is a timely title that looks at their anatomy, life history, taxonomy and ecology, and includes species profiles featuring stunning marine photography that will have you scanning the depths with renewed interest.