Sponges are pore bearers belonging to the phylum, Porifera.
Sponges actually possess no circulatory, digestive, or nervous system. Instead, constant water flowing through their bodies, collecting food and oxygen and removing waste is what they rely on. They are considered a sister group to all animals.
They can be found in a wide range of habitats, but are most commonly found in quiet, clear waters. Sediment brought in by waves and currents would restrict their pores’ ability to breathe and eat properly. The largest number of sponges can be found on rocks or other hard surfaces in the ocean.
They consume food by filtering food particles from the water that flows through them.
Adults are immobile, but some marine species are able to move very slowly at around 0.15 inches per day. Some tropical species are known to have a lifespan of nearly 200 years.
They do possess some defense mechanisms that deter predators. Many species shed a carpet-like element called spicules that fend off other Echinoderms. Some also have the ability to produce toxins to protect themselves.
There are four classes and over 5,000 species of sponge in the Phylum Porifera:
- Calcarea (Calcareous Sponges)
- Hexactinellida (Glass Sponges)
- Demospongiae (Demosponges)
- Homoscleromorpha (Homosclerophorida)
They are the last common ancestor of all animals, this makes them a sister group of all other animals.
