Effects of Dietary Vitamin C and E on Growth and Health of Largemouth Bass Micropterus salmoides 
Daryl Weldon, Ruguang Chen, and Rebecca Lochmann

Ten largemouth bass fingerlings with an average weight of 50.0 ± 0.03 g were stocked into each of eighteen 150-L tanks in a recirculation system and fed diets containing either 0 or 50 mg of vitamin E/kg of diet, and 0, 100 or 250 mg of vitamin C/kg of diet in a 2 x 3 factorial design. Fish were fed once daily to satiation for 12 weeks. There was no difference in weight gain, feed intake, or FCR between treatments through 10 weeks, but feed intake declined afterward. Improved hematology, epithelial integrity and disease resistance of LMB fed diets supplemented with vitamin E (versus the deficient diet) resulted in an increase in survival. Additional studies are needed to determine quantitative dietary requirements for vitamins C and E in largemouth bass.

Effects of Supplemental Vitamin C and a Dairy/Yeast Prebiotic on Fingerling Largemouth Bass Exposed to Heat Stress
Mini Jose, Ruguang Chen, and Rebecca Lochmann

Feed-trained largemouth bass fingerlings are normally held in vats for 4 weeks before being transferred to ponds for growout. At transfer, mortality escalates, and we wondered if short-term dietary interventions (during the 4-wk vat holding period) could improve survival of fish subsequently placed in ponds. Mortality is potentially due to a combination of factors, including heat stress, handling stress, and pathogen exposure, so we investigated the effects of diets supplemented with a dairy/yeast prebiotic, or high concentrations of vitamin C. Both supplements can stimulate the immune response in fish. Bass were fed an unsupplemented diet (control), or a diet with 2% prebiotic, or a total of 600 mg of vitamin C /kg of diet for 4 wks. There were no differences in growth or feed conversion during the trial, but survival was significantly lower in fish fed the prebiotic diet. After the trial, a subset of fish from each tank was subjected to heat stress at 34-35 ºC for 24 hours and monitored for mortality for five days. The heat stressed fish were challenged with bacteria (Edwardsiella tarda) at a concentration of 1.14× 10 ⁶ CFU/mL and survival was monitored for 21 days. Survival from the heat stress test was lowest in fish fed the prebiotic diet, but mortality from the bacterial challenge did not differ by diet.

2007-2008 Paddlefish ranching effects on plankton
Peter Perschbacher, Regina Edziyie and Bob Pierce

A study was undertaken in ponds and lakes in central Missouri where paddlefish juveniles had been stocked for ranching purposes. Sampling was performed monthly during the summer-fall in 5 stocked and 5 unstocked lakes greater than 1.2 ha for two years. Water samples for phytoplankton and zooplankton were taken from the upwind and downwind ends of the ponds and combined. Although effects were noted on plankton from paddlefish, climatic differences between the two years were judged the more important factor. HAB algae (Microcystis cyanea, Aphanizomenon sp. Anabaena spp.) were present, and somewhat reduced in incidence the first year in paddlefish lakes, but not in the second year. Experimental control of HAB algae by fingerling paddlefish may be due to the higher stocking levels (1360 kg/ha vs. ranching harvest biomass of 300-600 kg/ha) or the earlier life stage. Paddlefish, as seen in another filter-feeding fish Oreochromis aureus, seemed to accelerate normal species succession and reduced boom and bust cycling. Zooplankton were at times and by group reduced (and stimulated) by paddlefish, but levels were judged to remain adequate for planktivores, including fish fry, populations.

Propagation and Rearing Methods for Yellowcheek Darter Etheostoma moorei
Calvin Fisher, Steve Lochmann, Mitch Wine and Sherry Shoults

Yellowcheek darter Etheostoma moorei is found only in the shallow, high gradient riffles of the tributaries of the Little Red River in Arkansas. Over the last twenty years E. moorei has undergone a massive decrease in population.E. moorei was listed as a candidate species for addition to the Federal Endangered Species List in 2001. Our goal was to develop a successful propagation method, and once propagation had occurred to develop an effective feeding schedule to culture E. moorei larvae. Adults were captured from the wild using kick seining or snorkeling methods. Two females and one male were stocked into 57-L recirculating aquaria and fed a diet of blackworms 2-3 times per day. They were monitored continuously to observe spawning activity and to determine when spawning had occurred. When spawning was observed, the eggs were photographed at scheduled intervals until hatching occurred. Larvae were passively collected from the adult aquaria using the surface overflow as they swam up. Larvae were transferred to the 1.5-L black round rubber rearing tubs. The larvae were photographed every two days. Larvae were initially fed a mixture of saltwater rotifers (Brachionus plicatilus) at a rate of 10/mL, Nannochloropsis algae paste, and artificial plankton. Once they reached a large enough size, they were fed a mixture of rotifers (10/mL) and microcyst Artemia nauplii (2/mL). Three larvae survived long enough to develop pigmentation and a benthic behavior.