Growth of Juvenile Walleye, Stizostedion vitreum, Fed Two Dietary Protein Levels in Ponds

ABSTRACT

Juvenile walleye, Stizostedion vitreum, (127.4 ±3.2 g) trained to accept artificial diets, were stocked into six 0.04-ha ponds at a density of 8,275 fish/ha and fed one of two practical diets containing either 44% or 53% protein. Fish meal comprised approximately 53% of dietary protein in both diets. Fish were fed daily all of the floating test diets they would consume in 30 minutes at temperatures >15°C. At temperatures < 15 °C, walleye were fed a commercial sinking trout diet at 1% of body weight three days per week. The study period lasted 18 months (November 1995-May 1997). At final harvest there were no significant differences (P > 0.05) in total harvest weight (1,800 kg/ha), total specific growth rate (0.27), summer specific growth rate (0.59), or feed conversion ratios (8.4) between fish fed the two diets. However, fish fed 53% protein were significantly larger (P < 0.05) than those fed 44% protein: 304 vs. 256 g, respectively. These results indicate that walleye likely benefit from relatively high protein levels. Growth rates and feed efficiencies were relatively poor, with the best growth rates occurring at temperatures higher than predicted by previous studies.

Key Words:

• Walleye
• protein
• pond
• growth