Phylum Porifera

Body Structure


Sponges have a hollow middle and lots of pores. A sponges body structure is made of two parts, spongin and spicules. The spongin is the protein in the sponge and it provides the body support of the sponge. Spicules are the structure that serves as a skeleton. Sponges do not have any organs in their body, instead each type of sponge cell is responsible for a different activity to keep the sponge active and alive. For example pinacocytes are cells in the sponge that line the exterior of the body. They perform the same functions as skin cells. One end is attached to a solid such as a rock while the other end, called the osculum, is open to the environment.

Obtaining Food

Sponges are filter feeders because they do not move. They eat tiny, floating particles and plankton. There food is collected in cells called choanocytes and brought to other cells called ameobocytes. They obtain food by filtering out tiny particles from the water that goes through their bodies. They obtain the food through holes in their bodies.


Almost all sponges are hermaphrodites. Some sponges release sperm cells that randomly float to another sponge with the water current. If a sperm cell is caught by another sponge, then fertilization of an egg takes place inside the sponge. The egg becomes larva which use cilia to swim. The larva settles on the sea floor and becomes an adult. Asexual reproduction can occur through a process called budding. In budding, a small piece of the organism breaks away from the parent sponge and begins to grow in a new location.


barrel sponge

Sponges are very simple animals and live attached to the same place in the ocean forever. Sponges cannot move and therefore do not move. The only way they could move is by the oceans current. Sponges can be found attached to the ocean's surface anywhere to as deep as 29,000 feet or further.


Sponges have very dense skeletons and they can adapt themselves to the environment. Their skeleton type can allow them to live in different places like soft or hard sediments. Another adaptation is they can give off poison to protect them. they can also blend into different types of coral or environments. Sponges can live in either fresh water or salt water or known as the marine water. Sponges are able to grow into a new individual from the smallest piece of the original body through a process called budding. Most sponges consist of an outer wall dotted with lots of pores (ostia) of different sizes. This allows the free passage of water into the central part of the body, the atrium or spongocoel.

Importance to Humans

tube sponge
Sponges are very important to fish in the sea. They create homes for fish against predators and for small organisms. Sponges keep the sea running and we use the sea a lot and we eat a lot of fish. That is why sponges are important to humans. We also use sponges in cleaning. We use them to scrub our skin or scrub our cars! Also recent studies shows that sponges might be able to be used in medicine which could possibly help us in the future!