Survival, growth and prey of Esocidae in experimental systems

Survival (July to November) of young‐of‐the‐year esocids stocked in 0.2‐hectare experimental ponds in Missouri was: muskellunge (Esox masquinongy), 24%; northern pike (Esox lucius), 58%; and the F1 hybrid of these two species (commonly called the “tiger muskie”), 74%. Survival of yearlings from April to September was: muskellunge, 80%; northern pike, 90%; and hybrids, 85%. Growth rate of yearlings of all three forms was rapid in late spring, declined to a seasonal low in July, and then increased until the ponds were drained in September. Average weight gain of the hybrids (719 g) during their second year of life in ponds was significantly greater than that of northern pike (617 g) or muskellunge (615 g). Maintenance diets (grams of food per gram of fish) calculated for fish in tanks (1.2 × 4.8 × 1.1 m) for 28‐day periods were as follows: northern pike, 0.23; muskellunge, 0.51; and hybrids, 0.62. Food conversion efficiencies in tanks were: northern pike, 29.0%; muskellunge, 25.0%; and hybrids, 22.0%. Non‐game species were more vulnerable than game fishes to esocid predation in tanks. An esocid can be stocked in addition to or as an alternative to largemouth bass (Micropterus salmoides), walleye (Stizostedion v. vitreum), or striped bass (Morone saxatilis) because of a faster rate of growth. The hybrids may be the most desirable form of the three esocids because of rapid growth rate, intermediate angling vulnerability, and ease of rearing in a hatchery compared to either parent species.