In this article we will discuss about the nervous system of arthropods with the help of a suitable diagram.
Arthropods have a ladder like nervous system, with a double chain of segmental ganglia running along the ventral surface. The double chains part to encircle the esophagus, ending in a pair of dorsal ganglia. The dorsal ganglia are enough larger than the other ganglia to be called a brain.
However, many arthropod activities are controlled at the segmental level, as in annelids. For example, members of a number of species can move, eat, and carry on other functions normally, even after the brain is removed. In fact, in the arthropods generally, the brain appears to act not so much as a stimulator of the action of the animal but as an inhibitor, as in the earthworm.
The grasshopper, for example, can walk, jump, or fly with its brain removed; indeed, the brainless grasshopper responds to the slightest stimulus by jumping or flying. The extreme consequences of this releasing of inhibition can be seen in the praying mantis.
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Mantises are carnivorous and cannibalistic, and the female, being larger than the male, frequently captures her mate and, grasping him with her forelegs, begins to eat him, head first. This decapitation results in the release of strong motor activities by which the headless male struggles loose from the grasp of the female, mounts her, and mates with her.
The headless male is more likely to copulate than an intact male; investigators seeking to breed mantises have found that males of strains that do not mate readily in captivity will often do so after decapitation.