Phylum Arthropoda

Phylum Arthropoda

Arthropods are joint-legged animals and you must have come across a few of these animals. Some prominent ones include insects, spiders, ants, bees, crabs, shrimps, millipedes, centipedes, etc. Scientifically speaking, they all come under the Animal Kingdom under phylum Arthropoda.

The success of arthropods can mainly be attributed to the presence of exoskeleton, which makes them versatile, is protective in nature and also allows flexibility and mobility. You can see arthropods living on land and in water. They are also a source of food for many animals and human beings too.

Characteristic features of Phylum Arthropoda

  • The body structure shows bilateral symmetry.
  • They are triploblastic.
  • They can be found in all types of habitats – land, water, and soil.
  • They have jointed limbs.
  • The body is segmented into three regions – Head, Thorax and Abdomen.
  • The body cavity is filled with blood and is called the hemocoel. The blood is white in color.
  • The exoskeleton is hardened and is made of chitin.
  • They have a well-developed central nervous system.
  • The head is well developed and bears the sensory organs and brain.
  • They have compound eyes and mosaic vision.
  • The digestive tract is complete with the mouth and anus at opposite ends of the body.
  • They have an open circulatory system with dorsal heart and arteries.
  • Respiration is through the general body surface or by gills in aquatic forms and through trachea or book lungs in terrestrial forms.
  • Sexes are separate and sexual dimorphism is exhibited.