Influences of Feed Type on Alligator Gar Production in Tanks

Growth and survival of alligator gar larvae fed formulated feed and wild zooplankton, formulated feed and Artemia nauplii, or formulated feed, Artemia nauplii and wild zooplankton, from 5-21 dph were examined.  Alligator gar fed formulated feed alone served as a control.  Larvae were stocked into 75-L tanks at 2 larvae/L.  There were two replicates of each treatment and two controls in each of four recirculation systems.  Larvae offered live feed were fed at a rate of 5 prey^.mL^-1.d^-1 of wild zooplankton or Artemia nauplii. Larvae fed both types of live prey were fed at a rate of 10 prey^.mL^-1.d^-1.  All larvae were offered formulated feed at a rate of 10% of body weight/d.  At 12 dph, there was a significant difference in growth (F = 7.50, df = 31, P < 0.001), with the formulated feed and Artemia nauplii treatment having faster growth than the control.  At 21 dph, there were significant differences in growth among treatments (F = 3.57, df = 31 P = 0.026). The formulated feed and Artemia nauplii treatment had a significantly higher growth rate than the other two treatments and the control. However, the growth rate of Artemia and feed was only 0.16 mm/d faster than the control.  There were no significant differences in survival among treatments and the control. When time and costs are considered, the feed only treatment appears to be the most appropriate treatment for raising alligator gar to 21 dph.