Want to know more about different species of sponges in the world - The World Porifera Database: "The WPD, the World Database of all Recent sponges ever described, is part of the World Register of Marine Species (WoRMS), a global initiative to arrive at a register of all marine organisms. The WPD is a logical follow up and addition to the Systema Porifera (editors Hooper & Van Soest, 2002), the current update of the classification of all sponge taxa above the species level."