Friday, March 2, 2012
Sponges are living animals
Although I'm not able to walk along the beach at present, (because I'm still recovering from a hernia operation), every day Doug brings home treasures from the sea.
Today's treasure was a collection of sponges. As sponges are attached to rocks, look simple in structure and are colourful, many people mistake them for plants. In fact, sponges are animals made up of masses of living tissue supported on a simple skeleton. When you look at a sponge you can see thousands of tiny holes (pores) through which the sponge passes water, filtering out microscopic food particles.
Sponges do not have organs such as a stomach, liver and nerves. They are one of the simplest form of animals on Earth.
When beach combing along the shore, the skeletons of sponges are often found tangled up in flotsam. Most have lost their living colours and are a dull brown or bleached white colour, but they generally retain the shape they had when alive.
The shape of sponges varies widely and makes them interesting to collect. They range in form from fans, to cups, to tubes, to saucers. Some come with interesting common names such as dead man's fingers, hand sponges, terrace sponges, double fans, holy sponges and saucer sponges.
To the touch, sponges are soft.
Sponges do not grow in isolation; they are just one part of the rich ecology of the ocean. Their unusual shapes and bright colours, however, make them an attractive part of the marine scene.
Doug took this photo of me having an afternoon rest with my 15-year-old Siamese cat, Katie. She's the most delightful and affectionate animal friend I've ever had -- I love her dearly!
Posted by Robin's Double Life at 2:08 PM