Possible Clues:

• Leave rock — one is long in the water
• Snaky swimmer
• Conservative German, taking drug repeatedly, left fish
• Part of fisherman's catch has gone bad in his basket
• Fish gone astray in the fisherman's basket
• Fish listen to one dance tune, then another
• Fish has gone bad in angler's basket
• Predatory sea creature
• The sort of fish that's gone into the fish basket