Possible Clues:

• Grouper, e.g
• Fish with a 'Chilean' variety
• Sailor's back on ship pursuing ocean fish
• Fish related to the grouper
• Swimmer with the deep deep voice
• Deep, deep fish
• Fish in deep taken by aquatic mammal, mostly
• Chilean catch
• Soprano with energy, a singer and swimmer
• Corps eating each starter for breakfast with seconds; there's no meat course