Abstract
Sponges are mostly marine found distributed right from the intertidal region to the deeper waters of the oceans. Its spatial and temporal distribution is found ubiquitous. Though the sponges have simple morphology and anatomy, they show symbiotic association with several microorganisms, which are the main source of secondary metabolites and are capable of producing many biologically active compounds. So there is a good debate going on among the researchers that the source of such biologically active compounds/substances is either the sponge itself or the microorganism residing in the sponges. But unfortunately most of these symbiotic microorganisms are non-culturable. Anyhow the sponges as a whole are the good source of several substances covering the polyketides, alkaloids, terpenes, etc. This chapter deals with the variety of such chemical substances present in the sponges and their biological activities.