Read ORIGINS Animal Eve Sponges from the Shape of Life book.
This is a good overview of sponges: Ocean Animals - Sponges. Here is a description of sponges with illustrations: Sponges - The Simplest Animals.
Sponges are multicellular and were the first animals. The first genetic analysis has shown that sponges were the first animals. And most scientists thought that sponges were the first animal. Other scientists later argued that Ctenophore (comb jellies) were the first animals. By 2019 researchers showed sponges were indeed the first, but the argument likely will continue. One argument for sponges being the first animal is “ that some sponges can live and thrive on little oxygen".
Sponges have a very complex microbiome—a community of microorganisms—and each species has a very distinct set of microorganisms: Different Sponge Species Have Highly Specific and Stable Microbiomes.
There are many species of sponges, living from the shallow intertidal to the deep sea.
Sponge Videos
