Porifera
Sponges, with pores that let water flow through.
A fixed sponge
A sponge stays fixed in one place in the water. It cannot go to look for food.
How might food reach its cells?
What this lesson covers
The idea
Sponges (Porifera) are fixed aquatic animals, multicellular but without tissues or organs; water flowing through their many pores brings food and oxygen directly to cells and carries waste away.
A fixed sponge
A sponge stays fixed in one place in the water. It cannot go to look for food.
How might food reach its cells?
- Water carries it in through pores
- The sponge swims to it
- The sponge eats with tentacles
Water in, water out
Press Next step.
Cells served directly
A sponge has no tissues or organs. Each cell gets food and oxygen straight from the water that flows through the many pores, and the same flow takes the waste away.
Sponges (Porifera) are fixed aquatic animals, multicellular but without tissues or organs; water flowing through their many pores brings food and oxygen directly to cells and carries waste away.
Notes
Sponges (Porifera) are fixed aquatic animals without tissues or organs; water through their pores brings food and oxygen to cells and carries waste away.
Check yourself
What does Porifera mean in everyday words?
Which describes the body of a sponge?
What does water flowing through a sponge's pores do?
Where are sponges found?
- Pore-bearers — correct. Yes!
- Spiny skin. Echinodermata comes from echinos, meaning spiny, and derma, meaning skin.
- Jointed appendages. Arthropoda comes from arthro, meaning limbs, and poda, meaning appendages.
- A single cell. Sponges are multicellular.
- Multicellular but without tissues or organs — correct. Yes!
- Organ system level of organisation. Sponges lack organisation of tissues and organs.
- Pushes the sponge along the sea floor. Sponges remain fixed in one place.
- Gives the sponge tentacles. Tentacles are used by cnidarians to capture prey. A sponge is fed by water flowing through its pores.
- Brings food and oxygen to cells and carries waste away — correct. Yes!
- In aquatic environments, fixed in one place — correct. Yes!
- On dry land, moving about. Sponges remain fixed in one place and are found in aquatic environments.
- In the air. Sponges are found in aquatic environments.