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Hybrid Walleye (Saugeye)-

The Wisconsin Experience

Jim Held

Aquaculture Outreach Specialist

UW-Extension

jaheld@wisc.edu

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Why Walleye?

High market value

Wide-spread reputation as a food fish

Established fingerling production methods

Limited domestic supply

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Why Not Walleye?

Aggressive behavior

Easily disturbed by shadows and movement

Poor growth rate under intensive conditions

Diminution in growth rate before market size

(especially in males -sexual dimorphism)

+=Bear Deer Beer?

HybridizationThe advantages of some hybrid crosses are very obvious

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With certain fish species, interspecific crossbreeding has

resulted in hybrids having behavioral and growth

characteristics better suited for intensive culture than those

of purebred fishes. BUT NOT ALWAYS!

Examples:

Muskie x Northern Pike---Tiger Muskie

White Bass x Striped Bass--- Sunshine or Palmetto Bass

Plaice x European Flounder

Yellow Perch x Eurasian Perch

Natural hybridization between walleye and sauger

has been documented, and both reciprocal hybrids have

been artificially propagated in the laboratory.

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Hybrid walleye (Saugeye) have been stocked for

resource enhancement in as many as 11 states.

Limited impact?

Heterosis-Hybrid Vigor

Fertility

Overview• Growth studies over a decade ago established that walleye-

sauger hybrids grew as much as 2 times faster than the

purebreds.

• Organoleptic studies concluded that the hybrid walleye fillets

compared favorably with farm-raised purebreds, both of which

were preferred to wild-caught purebreds.

• Improvements in early spawning and fry feed-training

techniques provide the opportunity for out-of-season fingerling

production as well as eliminate the need for a pond phase of

production.

• Taken together these statements suggest that hybrid walleye

may be an ideal candidate for commercial RAS food fish

production.

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Question: Can we produce a food-size

hybrid from egg to plate in one year with

only indoor systems?

Objectives

• Use early season spawning and fry feed-training

techniques to produce hybrid walleye fingerlings in

indoor systems.

• Document key production characteristics for the

grow-out of hybrid walleye to food size in RAS.

• Provide farmers with food-size adult and feed-trained

hybrid fingerlings for market potential and field trials.

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Spawning and Feed-training• Early season spawning went as anticipated.

Two injections of hCG @500IU/kg 24 hours apart.

• Initially, brood stock sauger males were a challenge.

• Otohime diet, B1,B2, C1, 1.0mm Silver cup

• Fry training success was hard to quantify and highly variable.

• There was a learning curve.

• 85% survival from 4 inches to market size.

Materials and MethodsExperimental Tank Setup for Initial Rearing

•230 L round tanks

•Sidewalls painted black

•Gray bottom

•Adjustable lighting

•Flow

•24 hr feeders

•Surface spray

•Removable screens

•Daily cleaning system

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Surface

spray

Center screen

Directional

water flow

Otohime fry feed

200 -1400 m

Nelson Silvercup

walleye grower

1.0mm

Fry Feed

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20mm

60mm

Walleye/Saugeye Growth

0.0

100.0

200.0

300.0

400.0

4/23/09

5/7/09

5/21/09

6/4/09

6/18/09

7/2/09

7/16/09

7/30/09

8/13/09

8/27/09

9/10/09

9/24/09

10/8/09

10/22/09

11/5/09

11/19/09

12/3/09

12/17/09

12/31/09

1/14/10

1/28/10

2/11/10

2/25/10

3/11/10

Date

Saugeye

Walleye

Yellow perch

market size

Hybrid target

market size

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Weight Gain

0

50

100

150

200

250

300

350

4/20/12

5/20/12

6/19/12

7/19/12

8/18/12

9/17/12

10/17/12

11/16/12

12/16/12

1/15/13

2/14/13

3/16/13

4/15/13

Date

Saugeye

Walleye

Yellow perch

market size

Hybrid target

market size

1 year old Hybrid Walleye(1.0kg)

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Results• Brood stock injected in mid-April.

• Average fish size reached market target by December 1.

• Larger fish could be culled for sale by early November.

• Marketing could continue through the following March

• 50% yield for scaled skin-on fillets.

• Good market acceptance.

Challenges

• Availability of sauger brood stock

• Fry training learning curve

• Cannibalism

• Rearing density in RAS (55 kg/m3)

• Economics

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AcknowledgementsThis study is funded by State of Wisconsin support of the University of

Wisconsin Stevens Point Northern Aquaculture Demonstration Facility

and Wisconsin Department of Agriculture, Trade and Consumer

Protection Agricultural Development and Diversification Program grant

#’s 23001 and 25007. We also appreciate the assistance of the U.S.

Fish and Wildlife Service (Genoa, WI).