J. V. Shireman

The visible opaque bands in transverse sections of sagittal otoliths from bluegill (Lepomis macrochirus), redear sunfish (L. microlophus), and redbreast sunfish (L. auritus) were verified as annual rings. The verification was done using intraperitoneal injections of oxytetracycline followed by otolith examination after the fish were at liberty for 1 year in a north central Florida pond. Injections of 75 mg/kg wet body weight resulted in the best rate of fluorescent ring formation. Saggital otoliths from bluegill and redear sunfish populations in Newnans Lake Florida were sampled monthly to...

Black crappie (Pomoxis nigromaculatus) growth was reduced when hydrilla (Hydrilla verticillata) coverage exceeded 50% in Lake Baldwin, Florida, between 1977 and 1979. Black crappie did not reach harvestable size (>228 mm TL) until age 3 and 4 during periods of extensive hydrilla coverage and reduced threadfin shad (Dorosoma petenense) abundance. Following hydrilla removal and shad population reestablishment, harvestable size was obtained by age 2 and growth of older fish increased.