Possible Clues:

• Fish with a prehensile tail
• Fish that swims upright
• Upright fish
• Fish in the genus Hippocampus
• It's not an equine
• Sounds like something you'd see on beach at Laytown Races looks fishy?
• Southeast detests losing British and European fish
• Upright swimmer
• Hippocampus
• Fish whose female lays eggs in the male's pouch