Description Felty’s Slinky Fish Fly Baitfish imitations for clean water pelagic fish such as Spanish mackerel and other mackerel species these are essentially big fish flies to be utilised at various different times according to baitfish size and the fishs temperament. Fussy fish might require a smaller more transparent fly such as the Slinky fish , big fish in bluewater such as mackerel and trevally might want a big fly with plenty of flash. Or a better more realistic profile might be required if the fish are feeding on herrings then the magnetic minnow comes into its own its also a very good berley trail fly.