Which family do backswimmers belong to?

Backswimmers belong to the family Notonectidae, which is characterized by their unique swimming behavior and flattened body shape that allows them to move effectively through the water. This family includes insects known for their ability to swim underwater on their backs, using their long legs for propulsion.

Notonectidae is part of the order Hemiptera, specifically within the suborder Heteroptera (true bugs). Members of this family are often found in freshwater habitats such as ponds, marshes, and slow-moving streams. Their predatory nature and distinctive swimming style, where they utilize their legs to push against the water while maintaining a dorsal position, further define their adaptive traits.

The other families listed in the options represent different types of insects. Coenagrionidae encompasses a group of damselflies, Aeshnidae consists of large dragonflies, and Corduliidae includes the emerald dragonflies. While these families share the aquatic environment, they do not include the distinct swimming and predatory characteristics for which the backswimmer is known. Therefore, Notonectidae is the correct answer, highlighting the unique classification of backswimmers among aquatic insects.