The term Arthropoda is formed from the Greek words arthros meaning jointed and podos meaning foot. Those animals whose body has jointed appendages, bilaterally symmetrical, free circulatory system, hemoceles and exoskeleton containing chitin are called Arthropoda. Arthropoda is the largest group of animals. 80% of animals in the fauna are arthropods. The number of species is about 12,57,040. They are herbivores, carnivores or omnivours. Von Siebold (1845) named the order Arthropoda.