spongefly

/ˈspʌndʒˌflaɪ/
noun
  1. A small insect whose larvae live in freshwater sponges.
    • A spongefly's larvae help control the growth of freshwater sponges.
    • The spongefly is often found near lakes and slow-moving rivers.
    • Scientists study the spongefly to learn about aquatic ecosystems.