What is the defining anatomical feature of a spider's body plan, contrasting with the pond skater?
Answer
Two primary body segments: the cephalothorax and the abdomen
Spiders, belonging to Arachnida, exhibit a body divided into two main parts: the cephalothorax (a fusion of the head and thorax) and the abdomen, unlike the three-part structure of insects.

Related Questions
What class of animals do pond skaters officially belong to, distinguishing them from spiders?What is the key physical difference in leg count between a pond skater and a spider?How is the body plan of a pond skater divided, consistent with the insect blueprint?What specialized microscopic feature on the pond skater's legs is essential for remaining dry on the water surface?What natural physical force does the pond skater exploit to glide across the water?What is the specific order to which pond skaters (Gerridae) belong, grouping them with 'true bugs'?What type of mouthparts do pond skaters use for feeding on trapped insects?How do water striders primarily generate propulsion when moving toward captured prey?What feeding-related specialization do pond skaters lack that is characteristic of spiders?What conditions typically lead to the dominance of wingless (apterous) Gerridae forms?What is the defining anatomical feature of a spider's body plan, contrasting with the pond skater?