The more common name for the Porifera is the Sponge. Porifera are marine animals, although with an exception of a freshwater one. They are found in every known part of the ocean, and directly interact with many other animals in the ocean. One of these interactions is where a sponge grows on the shell of a snail that is being used by a hermit crab, and then will move around as the hermit crab does.
In general, sponges eat by filtering out bacteria out of the water around it, and are even capable of regulating the flow of water around it. There is an exception, however, where some sponges can capture crustaceans as they brush around it. The cells gradually draw the crustaceans in, and the cells digest it from the outside.
Porifera are both female and male. During different parts of a personal reproductive cycle, they produce either sperm or eggs. By releasing their sperm into the water, it may get carried and when it comes in contact with another Porifera of the same species, it may fertilize any eggs it may currently have. This does not apply to all porifera, as some reproduce asexually. Some porifera include the sea anemonae and the sea sponge.