Bullminnow Aquaculture

n Scientific Name –Fundulus grandis n Common Name –Gulf Killifish n Regional Names –Bullminnow - Alabama –Mudminnow - Texas –Cocahoe Minnow - Louisiana –Mummichogs - East Coast (F. heteroclitus)

Aquaculture Canidate? n Advantages –Popular live baitfish used to catch: n Flounder n Speckled Trout n Redfish –Price n Wholesale -$70-$100/1000 or $7-10/lb. n Retail -$1.50-$2.50/dozen or $12-20/lb.

Aquaculture Canidate? –Hardy n Tolerates wide range of water quality. n Handling stress is minimal n Low mortality at retail level n Long-lasting on the hook –Rapid growth n Spawn to Harvest - 2 to 6 months

Aquaculture Canidate? n Disadvantage –Need large number of broodfish. n Females produce a relatively low number of eggs compared to other culture species. – eggs per spawn –up to 1200 eggs per spawning season

Supply & Demand n Demand >>> Supply –April, May, June n Demand>Supply –July, Aug, Sep n Trapping Supply Undependable

Bullminnow Characteristics n Estuarine resident –Shallow waters of oyster bars, tidal creeks, saltmarhes pools, and bayous. n Sexes –Females - uniform greenish silver, darkening from bottom to top. –Males - Darker green with prominent gold speckling. Black patch ventrally along gill flap when ready to spawn.

Bullminnow Characteristics n Spawning –External fertilization –Fractional spawners –Exhibit semilunar spawning cycles –Adhesive eggs –Eggs will develop out of water in humid conditions –Spawning above 68 o F (20 o C) –Spawn March to October –Peak spawn - March and April –Minor peak- late August to early September

Bullminnow Eggs

Important considerations n Water quality –Salinity (single most important factor) n >=5 o / oo for efficient growth and production. –Dissolved oxygen n Generally above 4.0mg/L

Important considerations n Pond design –Small size (1/4 acre) or narrow for easy seining. –Average depth - 1 meter. –Smooth bottom for seining. –Graded for complete drainage. –Catch basin for harvest. –Free of aquatic vegetation.

Production systems n Three-pond system –Brood Pond –Hatching Pond –Grow-out Pond

Brood Pond n Stock brood fish in January at 10,000 fish/acre. n 2:1 females:male. n Feed high-protein feed at 3% body weight per day. n Add spawning mats when water temperature reaches 68 o F (20 o C).

Spawning Mats n Place in shallow water at pond edges. n Use PVC trellis to keep spawning mat above bottom. n Remove after 1 week. n Estimate eggs. n Transfer to Hatching Pond. n Limit transfer to 2 week period for uniform fry size.

Hatching Pond n Stock with 1.5 million eggs/acre. n Eggs will hatch in 2 to 3 weeks. n Expect 1 to 1.2 million fry. n Feed high-protein minnow feed at 5lb/acre/day. n Stock fry to grow-out ponds when they reach 0.5 grams or 1000fish/lb.

Grow-out Pond n Stock fry at a rate of 50,000 to 200,000 fish/acre. n Stocking rate dependent on market timing. n Feed 10% of stocked weight/day for 10 days, feed 5% body weight there after. n Sample fish every 2 weeks and adjust feed accordingly.

Production systems n Two-pond system –Brood Pond –Hatch and Grow-out Pond

Harvest n Harvest at approximately 4-5 grams or 100/lb n Market dependent n Partial Harvest –Trap –Seine n Complete Harvest –Drain

Post-Harvest n Place fish in holding tank for 24 hr without feed. –Get accurate weights and counts. –Recover from handling stress. –Purge gut contents which minimizes water fouling during transport.

Delivery or Pick-up? n Survey of bait dealers suggest they would pay the same price for pick-up or delivery. –Cost savings to wholesaler if the bait dealer picks-up his fish. n Fuel cost n Labor cost n Liability for the product n Concentrate efforts on harvest and supply

Recirculating Systems? n More control n Less water required n Smaller space requirements n Automation of feeding n Ease of sampling and harvest n Potentially less predation loss from birds n Capital intense

Recirculating systems?