 Bull Minnow Fundulus Grandis A.K.A. Gulf Killifish, Mud Minnows

Fundulus grandis  Member of the Fundulidae family, topminnows  Native to the Gulf of Mexico from Texas to the Keys, the eastern coasts of Florida and Cuba  Grows up to 18 cm  Favorite prey item of sport fish including flounder, speckled trout, and red snapper

Reproduction in Captivity  Reproduces well in captivity  Females don’t produce as many eggs as other cultures species  Egg adhere to spawning mats  Need large amount of spawners and space  Peak spawning from March-April and August-September

Production Methods: Spawning Pond  A pond devoted to egg production  10,000 fish per acre  2 females for every 1 male  Stock pond during January to February  When waters are warm (above 68ºF), spawning mats are placed along the edge of pond  Females attach eggs to bottom of mats

Production Methods: Hatching Pond  Pond dedicated to hatching fish and growing fry  No wild vegetation or fish in the pond  Water must be filtered through 285 µm mesh  1.5 million eggs can be loaded with 1 million expected to hatch  1 week before loading pond, 250lbs/acre of dried chicken manure should be added

Production Method: Growing Pond  Juveniles are moved to finish growing to harvestable size  Transfer to growing pond when ,500 fish/lb  Density dictates how large the fish grow  50,000 fish/acre=2.5” fish in 5 weeks  100,000 fish/acre=2.5” in 6+ weeks  When harvestable size, fish are removed by draining the pond and seining for them

Economic Enterprises  Sport fishing brings in billions of dollars to state’s economies  Demand for bait is high  Sold as live bait for flounder, speckled trout, and redfish  ~$11/lb for wholesale and ~$34/lb for retail  Wild stock typically relied upon but experimenting (successfully) with culturing

FOOD!!!  Bull minnows are om-nom-nom-nivores and will eat what’s avaliable  Phase 1 fish are fed small floating pellets 2x a day at 3% body weight/day  Once hatched, fish are fed ground minnow meal, 28-32% crude protein, 5lbs/acre/day  Phase 3 fish are fed floating pellets 2x a day at 10% body weight/day  After 10 days, feed decreases to 5% total weight.  After 2 weeks, decreased to 3% total weight.  Feed should not exceed 25lbs/acre/day

Life Cycle and Larval Stages  Spawning occurs in marsh vegetation  Lives in shallow waters of salt marshes, mangrove swamps, oyster beds, etc.  External fertilization  Eggs can tolerate exposure to air and can be kept in moist containers  Reaches sexual maturity around ”  Lives up to 4 years (5.5”), few survive to 3 years  Sexually dimorphic

Sexual Dimorphism in F. grandis Females larger than males Males have more coloration than females

Chemical and Environmental Requirements  Brackish water from 5-30 ppt, lower salinity affects growth and immunity  A few shallow, 1m ponds with properly sloped bottoms  Water needs to be fertilized to stimulate natural foods (plankton)  For aquatic insect treatment, 2 pints/acre of diesel and 2 gal/acre is added before stocking  Surprisingly, some states don’t like you to do this

Pros and Cons to Culturing F. grandis Advantages  Very tolerant of water qualities  Low mortality rates and high fish health  Stays alive in transport and on a baited hook  Fast growing and uniform sizing Disadvantages  Costly to start up and maintain  Low number of eggs produced by females  Dependent on market demand and time of year  In grand scheme of aquaculture, little is known about culturing bull minnows

Acknowledgements  Southern Regional Aquaculture Center (Texas A&M)  Growing-Bull-Minnows-for-Bait.pdf  Auburn University Marine Extension and Research Center  Minnows_in_Alabama.pdf  Dr. Cortney Ohs (University of Florida)  dade.ifas.ufl.edu/environment/documents/aquaculture/Ohs_Mar ine%20Baitfish_Overview.pdf