Study design
Concurrent tank and pond experiments were performed with juvenile channel catfish to resolve temporal patterns in the stable isotope values of fish with forced and natural diet shifts. The laboratory tank experiment was designed to quantify the isotopic transition patterns in muscle tissue of fish subjected to constant and abruptly changing diets between foods with known, distinct δ13C and δ15N contents. These results were then applied to interpret the temporal isotopic
patterns in muscle tissue of fish reared in the pond experiment with access to dynamic live prey communities and manufactured feed. Channel catfish used in both experiments were hatched from the same brood stock at the Senecaville State Fish Hatchery, Ohio, USA. Eggs were collected from spawning cans placed in ponds, hatched in jars, and then larvae were reared for about two weeks in flow-through troughswithmultiple daily feedings of a powderedmanufactured feed