Bull Minnow AquacultureBull Minnow Aquaculture

LaDon SwannLaDon SwannAuburn UniversityAuburn University

Mississippi-Alabama Sea Grant Mississippi-Alabama Sea Grant ConsortiumConsortium

Bullminnow AquacultureBullminnow Aquaculture• Scientific NameScientific Name

– FundulusFundulus grandisgrandis

• Common NameCommon Name– Gulf KillifishGulf Killifish

• Regional NamesRegional Names– Bullminnow - AlabamaBullminnow - Alabama– Mudminnow - TexasMudminnow - Texas– Cocahoe Minnow - LouisianaCocahoe Minnow - Louisiana– Mummichogs - East Coast (Mummichogs - East Coast (F.F. heteroclitusheteroclitus))

Bullminnow CharacteristicsBullminnow Characteristics

• Estuarine residentEstuarine resident– Shallow waters of oyster bars, tidal Shallow waters of oyster bars, tidal

creeks, salt marsh pools, and bayous.creeks, salt marsh pools, and bayous.

• SexesSexes– Females - uniform greenish silver, Females - uniform greenish silver,

darkening from bottom to top.darkening from bottom to top.– Males - Darker green with prominent gold Males - Darker green with prominent gold

speckling. Black patch ventrally along gill speckling. Black patch ventrally along gill flap when ready to spawn. flap when ready to spawn.

Bullminnow CharacteristicsBullminnow Characteristics• SpawningSpawning

– External fertilizationExternal fertilization– Fractional spawnersFractional spawners– Exhibit semilunar spawning cyclesExhibit semilunar spawning cycles– Adhesive eggs Adhesive eggs – Spawning above 68Spawning above 68ooC.C.– Spawn March to October.Spawn March to October.– Peak spawn - March and April Peak spawn - March and April – Minor peak- late August to early SeptemberMinor peak- late August to early September

Aquaculture Candidate?Aquaculture Candidate?

• AdvantagesAdvantages– Popular live baitfish used to catch:Popular live baitfish used to catch:

FlounderFlounder Speckled TroutSpeckled Trout RedfishRedfish

– PricePrice Wholesale -$70-$100/1000 or $7-10/lb.Wholesale -$70-$100/1000 or $7-10/lb. Retail -$1.50-$2.50/dozen or $12-20/lb.Retail -$1.50-$2.50/dozen or $12-20/lb.

Aquaculture Candidate?Aquaculture Candidate?

– HardyHardy Tolerates wide range of water quality.Tolerates wide range of water quality. Handling stress is minimalHandling stress is minimal Low mortality at retail levelLow mortality at retail level Long-lasting on the hookLong-lasting on the hook

– Rapid growthRapid growth Spawn to Harvest - 2 to 6 monthsSpawn to Harvest - 2 to 6 months

Aquaculture Canidate?Aquaculture Canidate?

• DisadvantageDisadvantage– Need large number of broodfish.Need large number of broodfish.

Females produce a relatively low Females produce a relatively low number of eggs compared to other number of eggs compared to other culture species.culture species.

– 10-200 eggs per spawn10-200 eggs per spawn– up to 1200 eggs per spawning seasonup to 1200 eggs per spawning season

Supply & DemandSupply & Demand

• Demand >>> SupplyDemand >>> Supply– April, May, JuneApril, May, June

• Demand>SupplyDemand>Supply– July, Aug, SepJuly, Aug, Sep

Important ConsiderationsImportant Considerations

• Water qualityWater quality– Salinity (single most important factor)Salinity (single most important factor)

>=5 ppt for efficient growth and production.>=5 ppt for efficient growth and production.

– Dissolved oxygenDissolved oxygen Generally above 4.0mg/LGenerally above 4.0mg/L

Important ConsiderationsImportant Considerations

• Pond designPond design– Small size (1/4 acre) or narrow for easy Small size (1/4 acre) or narrow for easy

seining.seining.– Average depth - 1 meter.Average depth - 1 meter.– Smooth bottom for seining.Smooth bottom for seining.– Graded for complete drainage.Graded for complete drainage.– Catch basin for harvest. Catch basin for harvest. – Free of aquatic vegetationFree of aquatic vegetation

Production SystemsProduction Systems

• Three-pond systemThree-pond system– Brood PondBrood Pond– Hatching PondHatching Pond– Grow-out PondGrow-out Pond

¼ acre brood pond

¼-1 acre hatching pond

1-5 acre grow-out pond

Brood PondBrood Pond• Stock brood fish in Stock brood fish in

January at 10,000 January at 10,000 fish/acre.fish/acre.

• 2:1 females:male.2:1 females:male.• Feed high-protein feed at Feed high-protein feed at

3% body weight per day.3% body weight per day.• Add spawning mats when Add spawning mats when

water temperature water temperature reaches 68reaches 68ooC.C.

Spawning MatsSpawning Mats• Place in shallow water at pond Place in shallow water at pond

edges.edges.• Use PVC trellis to keep Use PVC trellis to keep

spawning mat off bottom.spawning mat off bottom.• Remove after 1 week.Remove after 1 week.• Estimate eggs.Estimate eggs.• Transfer to hatching pond.Transfer to hatching pond.• Limit transfer to 2 week period Limit transfer to 2 week period

for uniform fry size.for uniform fry size.

Hatching PondHatching Pond• Filter incoming water.Filter incoming water.• Fertilize 40lbs/acre 12-12-12Fertilize 40lbs/acre 12-12-12• Treat pond for air-breathing insects.Treat pond for air-breathing insects.• Stock with 1.5 million eggs/acre.Stock with 1.5 million eggs/acre.• Eggs will hatch in 2 to 3 weeks.Eggs will hatch in 2 to 3 weeks.• Expect 1 to 1.2 million fry.Expect 1 to 1.2 million fry.• Feed high-protein minnow feed at 5lb/acre/day.Feed high-protein minnow feed at 5lb/acre/day.• Stock fry to grow-out ponds when they reach 0.5 Stock fry to grow-out ponds when they reach 0.5

grams or 1000 fish/lb.grams or 1000 fish/lb.

Grow-out PondGrow-out Pond• Stock fry at a rate of 50,000 to Stock fry at a rate of 50,000 to

200,000 fish/acre.200,000 fish/acre.• Stocking density Stocking density

– dependent on market size.dependent on market size.– Higher rates means smaller fish at harvestHigher rates means smaller fish at harvest

• Feed Feed – 10% of stocked wt/day for 10 days10% of stocked wt/day for 10 days– 5% body weight there after.5% body weight there after.

• Sample fish every 2 weeks and adjust Sample fish every 2 weeks and adjust feed accordingly.feed accordingly.

Production SystemsProduction Systems

• Two-pond systemTwo-pond system– Brood PondBrood Pond– Hatch and Grow-out PondHatch and Grow-out Pond

• Leave eggs in pondsLeave eggs in ponds– Fewer pondsFewer ponds– Less control of densitiesLess control of densities

¼ acre brood pond

1-5 acre hatching/grow-out

pond

HarvestHarvest

• Partial HarvestPartial Harvest– TrapTrap– SeineSeine

• Complete HarvestComplete Harvest– DrainDrain

Post-Harvest Post-Harvest • Place fish in holding Place fish in holding

tank for 24 hr without tank for 24 hr without feed.feed.– Get accurate weights Get accurate weights

and counts.and counts.– Recover from handling Recover from handling

stress.stress.– Purge gut contents Purge gut contents

which minimizes water which minimizes water fouling during fouling during transport.transport.

Delivery or Pick-up?Delivery or Pick-up?• Survey of bait dealers suggest they Survey of bait dealers suggest they

would pay the same price for pick-up or would pay the same price for pick-up or delivery.delivery.– Cost savings to wholesaler if the bait Cost savings to wholesaler if the bait

dealer picks-up his fish.dealer picks-up his fish. Fuel costFuel cost Labor costLabor cost Liability for the productLiability for the product Concentrate efforts on harvest and supplyConcentrate efforts on harvest and supply