Possible Clues:

• Marine beast, the male having a mane
• Large-eared mammal of Pacific Ocean, like Leo
• Animal has to close in to catch duck
• Is alone (anag.)
• Stick one on the end of this big brute
• Acrobatic aquatic mammal
• Large marine mammal
• Flippered animal of the Pacific
• Marine animal, used as a circus performer
• Stick up what gets charged for a life on the ocean wave