To test large scale, semi-commercial, intensive culture system for walleye fry.
To demonstrate the day to day management of walleye culture system.
To determine the effect of enriched Artemia on walleye growth.
To carry out a demonstration workshop for interested farmers and State Hatchery Personnel.

Walleye is a highly valued fish and in great demand in the Midwest region. Intensive culture of this species in controlled conditions is an economical alternative and complementary way of production to highly unpredictable conventional pond culture. The common understanding exists that for commercial walleye aquaculture to be successful methods are needed for maturing and spawning of broodstock held in captivity (Malison et al. 1998). Therefore, if out of season, induced spawning is the strategy of production then intensive indoor fry culture is the only alternative. Intensive culture of walleye is gaining favor and extensive research is being devoted to this possibility in recent years (Moore and Prange, 1994; Bristow and Summerfelt, 1994; Britow et al., 1996).

The Piketon Research and Extension Center is capable of demonstrating the culture of walleye using the most recent innovations in this regard. Based on the experiences gained from the last year larval walleye feeding study (Kolkovski et al., 1997) on the experimental scale (40 L tanks equipped with clay supply and surface breaking sprinkler (see Bristow et al., 1996)). We propose to enlarge already established culture techniques into 1000 L tanks with larval density of 20-40,000 fish.

In February 1998 we successfully spawned two female walleyes after photothermal manipulation and hormonal injections. Eggs are currently incubated and fertilization is 50-80%. This larvae are intended as the first batch for mass rearing, whereas larval walleye obtained during regular season (May) will constitute the second batch for rearing.

Three round (1000 L) tanks will be used. The system will be located in the main aquaculture room. The water will be supplied from the holding tank above the "walleye" system in the main room at the rate of 2L/min to each tank.

Two experiments were conducted to evaluate survival and growth of walleye (Stizostedion vitreum) larvae reared initially on live brine shrimp Artemia nauplii and then gradually weaned to commercial diets. Wild captured walleye were held in earthen pond beginning late November, and then gradually transferred to higher water temperatures prior to hormonally induced ovulation in February. Second batch of walleye larvae was obtained from a regular hatchery operation in April and reared in similar conditions. Larvae were stocked at 20 ind/L and raised in large triplicate tanks (800 L each) provided with turbid water (40-50 NTU) and surface sprays. Mean final weight of fish after 32 days of rearing from the first (February) and second (April) batch did not differ significantly, 100.5 + 17.5 and 111.2 + 18.0 mg, respectively, whereas survival was 6 + 1.9 and 47 + 1.6% in out-of-season and regular season produced juveniles. In this study, water temperatures were below optimum for growth of walleye and survival and growth can be greatly enhanced by further improvements in husbandry.