New investigations into golden shiner culture

摘要

Survival of golden shiner Notemigonous crysoleucas larvae fed nine different formulated diets was evaluated in 2007 and 2008. Fry (1-d post hatch) were stocked equally into indoor tanks and then pair-wise comparisons were ran to evaluate differences in survival among different prepared foods in 14-d culture trials. In 2007 six diets were evaluated and in 2008 three more diets were evaluated against the best performing diet from the 2007 trials. Stocking rates ranged from 8-40 fry/L. In 2007, only the ZeiglerTM AP100 trial resulted in any survival of fry. That diet was then used in 2008 as the control for additional pair-wise comparisons. Results from the 2008 culture season showed ZeiglerTM AP100 again yielded the best survival; mean survival ranged from 1-28%, while the other three diets had mean survival that ranged from 4-6%. Results from this study show that more effort needs to be directed toward developing a more nutritionally complete diet for golden shiners. In addition, there is need to refine better culture techniques for growth and survival in indoor tank systems. Better feeds and improved culture methods are also needed to support the growth of the golden shiner industry in indoor systems.Organic fertilizer was compared to a mix of organic and inorganic fertilizers for the culture of golden shiners (Notemigonus crysoleucas) in 0.08-ha earthen culture ponds in 2007. Age-1 broodstock were stocked (51.6 kg/ha) on May 1, 2007 and all ponds were harvested October 29-November 1, 2007. Organic fertilization consisted of one application of soybean meal at a rate of 9.1 kg/pond/week followed by weekly applications at a rate of 4.5 kg/pond/week for 5 weeks. Nitrogen (36-0-0) fertilizer was used for 4 weeks to adjust nitrate-nitrogen to total phosphorus ratios (NO3-N:TP) to 7:1 on the mixed fertilizer treatment. Water temperature, DO, and pH were all within acceptable ranges for golden shiner pond culture. Nitrite levels were low in both treatments throughout the culture period. Ammonia-nitrogen (TAN) had the largest difference between treatments with the mixed fertilization treatment having elevated TAN levels compared to the organic fertilizer only treatment. Golden shiner fry collected at harvest in the organic only fertilization treatment averaged 71.2 mm + 8.8 in length while those harvested in the mixed fertilization treatment averaged 82.2 mm + 4.0. Golden shiner fry in the organic only treatment averaged 4.6 g + 2.6 in weight while the fry in the mixed fertilization treatment averaged 4.9 g + 0.8. Total production from this experiment was 537 kg/ha + 148.7 in the organic only treatment and 548 kg/ha + 63.5 in the mixed fertilization treatment; total age-0 golden shiner fry numbers harvested averaged 326,215/ha + 186192 in the organic only treatment and 115,972/ha + 20764 in the mixed fertilization treatment. The average length, weight, and production (weight and numbers/ha) were all found to be not significant (P\u3c0.1). Diet selection was evaluated by examination of contents of fish stomachs and Chydorus and cyclopoids were the preferred prey species in both treatments.