Marine Biology, the study of lives in the marine environment, the environment large enough to cover three fourth of earths space. The marine ecosystems have varying diversity. Out of the total thirty two animal phyla, fifteen are represented by the taxa, in the marine ecosystem. There are more than 230000 species in the world oceans. The book not only highlighted the important marine fauna and flora with their distinguishing characters, but also on the assemblage and biology of many of the inhabitants, including some of the special traits of marine life.