shellcracker

/ˈʃɛlˌkrækər/
noun
  1. A freshwater fish (Lepomis microlophus) also called redear sunfish, known for eating snails and having a red spot on its gill cover.
    • Shellcrackers are popular with anglers because they put up a good fight.
    • We caught a big shellcracker while fishing in the lake.
    • The red spot on the shellcracker's gill makes it easy to identify.