Evaluation of Two Sizes of Hybrid Striped Bass for Introduction into Small Ponds

Abstract

Private recreational fisheries in small impoundments provide a potential new market for the growing industry producing hybrid striped bass Morone saxatilis. We estimated growth, condition, and survival of hybrid striped bass (female striped bass × male white bass M. chrysops) in two small ponds with established fisheries for largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus that eventually experienced severe weather-induced fish kills 266 d and 348 d after stocking. Both ponds were stocked with 40 phase 2 (120–169 mm total length, TL) and 22 phase 3 (241–344 mm TL) hybrid striped bass/ha. Growth and condition were monitored from introduction until the occurrence of fish kills. Fish collections immediately following the kills allowed minimum estimates of survival for time at large before each event. Mean growth rates were near 0.35 mm/d for phase 2 hybrids and ranged from 0.13 to 0.21 mm/d for phase 3 hybrids. Mean relative weight (W_r ), which at the time of stocking was optimal (100), decreased to near 85 for phase 2 hybrids and near 75 for phase 3 hybrids after 300 d at large. Adjusted annual survival estimates over the period from stocking until initiation of the fish kills were 42.3% and 58.6% for phase 2 hybrid striped bass and 56.0% and 66.6% for phase 3 fish. Based on purchase price and relative survival of the two size-groups, phase 2 hybrid bass are the more economical choice for stocking recreational ponds that have established sport fish communities.