Skeleton and Water Currents
The skeleton of a sponge helps to support it. The skeleton may be made of spicules, microscopic needle-like spikes. These spicules are composed of amoebid cells. Spicules are also made of calcium carbonate or silica and can come in different shapes. Besides spicules, sponges may be made up of spongin, fibrous protein made of collagen. The skeleton is an important characteristics in sponge taxonomy.
Water currents help the sponge receive the elements it needs, such as food and oxygen, and they also carry away metabolic and digestive waste.
Water currents help the sponge receive the elements it needs, such as food and oxygen, and they also carry away metabolic and digestive waste.