As one might expect, smaller fish species and lighter fishing conditions are the primary uses for ultralight spinning rods. Trout, bluegills, perch, crappies, and other smaller species are around the planet. To capture fish, you need to cast farther, use better lure actions, and manipulate the lure better. To operate well and provide you with long throwing distance, ultra-small lures like spinners, spoons, crankbaits, and others need ultra-light action rods.