Which animal has four pairs of legs, spins silk for its web and has a cephalothorax and abdomen?

Spiders have eight legs (four pairs), are capable of spinning silk webs and have an abdomen and cephalothorax. The main body parts of a spider are an abdomen and a cephalothorax. The front portion of spider's body is known as a cephalothorax and contains the legs, eyes, mouth, etc. Cephalothorax is connected to the abdomen through a thin stalk. The abdomen is home to spinnerets (typically 6 in number), the organ that is responsible for spinning of silk webs. These webs are not only useful for catching food, but also for making sperm webs, protection of developing eggs, etc. The silk produced by spiders has very high tensile strength and is capable of extending to great extents. The abdomen also contains other vital organs, such as, lungs, reproductive organs, etc. 

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