Importance of Resident and Seasonally Transient Prey to Largemouth Bass in the St. Johns River, Florida

Abstract

AbstractWe examined seasonal dynamics of prey availability and diets of Largemouth Bass Micropterus salmoides in the St. Johns River, Florida. The four most common prey species were Threadfin Shad Dorosoma petenense, Bay Anchovy Anchoa mitchilli, Atlantic Croaker Micropogonias undulatus, and Atlantic Menhaden Brevoortia tyrannus. The number of prey found in Largemouth Bass varied significantly by month (year‐round) and predator size (“small,” <356 mm TL, n = 267; “medium,” 356–432 mm TL, n = 205; “large,” >432 mm TL, n = 114). Atlantic Menhaden were most energetically beneficial to predators when available. Of the four most common prey species collected in trawls, only menhaden trawl catch was positively correlated with its appearance in bass diets. Menhaden were eaten by bass of all sizes, but were found only from September through November. Largemouth Bass did not feed heavily on juvenile anadromous shads Alosa spp. during their autumn migration, but this likely reflected low abundance of these clupeid species. The seasonal diversity of prey available in the St. Johns River may contribute to its being one of the most productive Largemouth Bass fisheries in Florida.Received June 23, 2014; accepted October 22, 2014