|
|
Sponges
Sponges grow in the sea.
They are not plants, but animals.
They suck in water and pump it out.
Their body takes food out of the water.
People use dead sponges for washing.
What is a sponge?
Sponges look like plants, but they are in fact animals. They are a very simple animal with no nerves, muscles or other sense organs. Most sponges live in the the ocean.
Different kinds
There are many different kinds of sponges, about 5000 so far, and they are many different colours and shapes. They grow in two ways however: encrusting or free-standing.
Encrusting sponges grow a bit moss does, covering surfaces of rocks.
Free-standing sponges grow into strange shapes and can get very big. These are the kind that people are most familiar with.
This kind of sponge is called 'yellow finger' for obvious reasons!
Feeding
A sponge is covered with tiny pores that link to a system of canals and eventually to larger holes. The canals move water through the sponge's body. Special cells line the canals. These cells take food and oxygen from water the sponge pumps through its body, and take out waste from the canals to be released into the sea.
Life Cycle
Most sponges are both male and female. They produce both sperm and eggs. On the same night (usually with a full moon), sponges of one kind all release both sperm and eggs into the water. Sperm and eggs meet and the eggs are fertilised. Larvae float around, then lodge somewhere and start to grow.
Fish and some kinds of turtles eat sponges.
Use by humans
Skeletons of dead sponges are used by people, generally for washing or for applying make up or lotions. Natural sea sponges are odd shapes. The coloured sponges you see that are shaped like balls or bricks are not natural sea sponges, but made in a factory.
Find out more about sponges and see photos here:
http://www.seasky.org/reeflife/sea2a.html
http://www.enchantedlearning.com/subjects/invertebrates/sponge/coloring.shtml
Acknowledge this source in your bibliography like this:
Sponges (2003). [Online], Available: www.kidcyber.com.au
updated September 2007