Tag: adaptations

In earthworms there are specialised nerves with photoreceptors in the nerve endings present in the skin and the impulses from these nerves are carried rapidly to the muscles of the earthworm. This makes them sensitive to stimuli such as light and sound. 

• The Earthworm’s skin is protected by a thin cuticle and kept moist by a slimy mucus.  This lets it absorb the oxygen it needs and expel carbon dioxide.  If a worm is dried up by the sun, it will die because the exchange of gases can’t take place.
  
• Asphyxia is the condition where the body either doesn't get enough oxygen to continue normal function or has too much carbon dioxide to function properly. Without adequate oxygen, nerve cells in the brain begin to die in about 2-4 minutes, and cell death is irreversible. 
  

• Except for the first, clitellar and last segment, all the other segments have eight setae located around each segment. 
• The setae look like small bristles sticking out of the earthworm’s skin. The setae can be retracted and are for moving through the soil. The bristle-like setae anchor the segments as they crawl.
  

Ureotelic organisms are those that excrete nitrogenous waste in the form of urea. Earthworms are ureotelic since their nitrogenous waste composition consists of 40% urea and 20% ammonia.