Invertebrates: A Quick Reference Guide By Julian Sprung A NEW beautiful and comprehensive reference for aquarists, divers and naturalists, with more than 650 full color photographs identifying more than 500 species of marine invertebrates.This book is the essential guide for all aquarists who want to make the right choices when stocking an aquarium with invertebrates or purchasing invertebrates for a reef aquarium. 240 pages, hardcover. This book is a MUST HAVE for any saltwater reef hobbiest!!! This book has been on the BEST-Seller list since it was published!