Effect of Rearing Experience on the Survival, Growth, and Behavior of Hatchery‐Reared Largemouth Bass

Abstract

AbstractLargemouth Bass Micropterus salmoides are commonly stocked throughout their native range, but survival of stocked fish is variable and often low. Hatchery fish may have difficulty switching to natural forage; therefore, providing feeding experience with natural prey in the rearing environment could result in improved growth and survival of Largemouth Bass after stocking. We conducted pond experiments to evaluate differences in growth and survival of Largemouth Bass reared in raceways and fed pellets or in ponds and fed either Bluegill Lepomis macrochirus prey or Fathead Minnow Pimephales promelas prey. Largemouth Bass reared on one of these three diets were stocked into ponds containing Bluegill prey. After 2 months, pellet‐reared Largemouth Bass were significantly smaller than fish reared either on Fathead Minnows or Bluegills, whereas fish reared on either Fathead Minnows or Bluegills were similar. Fathead Minnow‐reared Largemouth Bass had lower survival than Bluegill‐reared fish, but no other survival differences were observed. To determine possible mechanisms influencing differential growth and survival of juvenile Largemouth Bass, we also conducted laboratory experiments examining the influence of prior feeding experience (pellets, Bluegills, or Red Shiners Cyprinella lutrensis) on foraging behavior and prey capture success in pools. Largemouth Bass reared on live forage captured prey faster, ingested more prey, and had higher capture efficiencies than did fish reared on pellets. Combined, pond and laboratory experiments show prior acclimation to live prey may ultimately be beneficial to increasing growth of stocked hatchery Largemouth Bass and could result in increased recruitment. We recommend additional exploration of acclimation of Largemouth Bass fingerlings to natural prey, preferably Bluegills, prior to stocking to determine whether hatchery managers should consider alternative rearing techniques.