Feeding Regime Has Little Impact on Weight Loss of Hybrid Crappies Pomoxis spp. and Redear Sunfish at a Low (Winter) Water Temperature when Fed a Noncommercial Diet of Blood Worms

Abstract

AbstractWinter mortality is a problem for fish producers in temperate regions of the USA, including Arkansas. Hybrid crappies (Black Crappie Pomoxis nigromaculatus × White Crappie P. annularis) and Redear Sunfish Lepomis microlophus are popular among recreational anglers. Methods of winter feeding vary widely among existing commercial farms. The impact of different winter feeding regimes on performance of hybrid crappies and Redear Sunfish was evaluated in temperature‐controlled aquarium systems. Juvenile hybrid crappies and Redear Sunfish were cultured at approximately 9°C to mimic winter conditions. Three feeding regimes were implemented (3 tanks/regime) in which an ad libitum ration of blood worms was administered twice per week, once per week, or once per month. After 13 weeks of culture, there were no observed differences in weight loss, survival, specific growth rate, or final individual weight for either hybrid crappies or Redear Sunfish. Hybrid crappies lost 27–29% of their initial body weight, while Redear Sunfish lost more than 30% of their initial body weight. Fatty acid composition of both species differed significantly among feeding treatments, showing a decline in saturated fatty acids from initial levels and increases in or static levels of highly unsaturated fatty acids. Results suggest that feeding regime has little effect on weight gain in hybrid crappies and Redear Sunfish when fed at a colder water temperature.