Culture of Sunshine Bass, Morone chrysops × M. saxatilis Fry in Tanks with Zooplankton Cropped from Ponds with a Drum Filter

Abstract

Sunshine bass, Morone chrysops X M. saxatilis fry were stocked at 20 fry/L into 260-L tanks when 4 days old and harvested 21 days later. Zooplankton were fed to the fry at rates of 10, 20, or 30 plankton/mL once per day with three replicates of each treatment. Zooplankton were collected with a drum filter from ponds managed to maximize rotifer densities at the time of filtration. The Zooplankton were retained by a 60-μm mesh filter but passed through a 150-μm mesh. Beginning at age 9 days, fry were also offered a <150-μm microencapsulated, 50% protein fry feed at 1 g/2.4 hour. Mean survival rates at harvest were 3.1%, 14.2%, and 24.3% in low to high feeding treatments. Fry from the 30 zooplankton/mL treatment survived at a significantly higher rate than fry from the 10 zooplankton/mL treatment. Average total lengths of fry were 8.24 mm, 8.15 mm, and 7.66 mm and were inversely related to survival with fish from the 30 zoo-plankton/mL treatment, having significantly smaller fry than the other treatments. Use of a drum filter appears to be a practical way of cropping appropriately sized Zooplankton for use in sunshine bass fry culture.

Key Words:

• Sunshine bass
• Morone
• fry
• drum filter
• Zooplankton