Which order is characterized by long slender bodies, large eyes, and aquatic nymphs?

• A. Orthoptera
• B. Ephemeroptera
• C. Odonata
• D. Mantodea

Answer: (C)

The order described by long slender bodies, large eyes, and aquatic nymphs is Odonata, the group that includes dragonflies and damselflies. Adults in this order have elongated, streamlined bodies and very prominent eyes that give them excellent vision for catching prey in flight. The immature stage, the naiad, lives in water and is also predatory, using specialized mouthparts to grab prey underwater before metamorphosing into the winged adults. This combination of aquatic nymphs plus a distinctive winged adult form with an elongated body is a hallmark of Odonata, distinguishing it from other insect orders like Orthoptera (grasshoppers and crickets, which are mostly terrestrial), Ephemeroptera (mayflies, which have aquatic naiads but different adult wing form and body traits), and Mantodea (mantises, which are terrestrial and have raptorial forelegs).