1) Aquatic carnivorous insects 2) Arthropod family 3) Family notonectidae 
Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called Backswimmers because they swim upside down. The Common Backswimmer, Notonecta glauca, is widespread in the United Kingdom, where it is known as the greater water boatman, and in Europe. Nonectidae are similar in appearance to Corixidae (common names `....
[n] - aquatic carnivorous insects
family Notonectidae noun aquatic carnivorous insects