Bull Minnow Fundulus Grandis A.K.A. Gulf Killifish, Mud Minnows.
-
Upload
bruno-baker -
Category
Documents
-
view
223 -
download
1
Transcript of Bull Minnow Fundulus Grandis A.K.A. Gulf Killifish, Mud Minnows.
S
Bull MinnowFundulus 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
900-1,500 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 1.6-2.0”
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) http://fisheries.tamu.edu/files/2013/10/SRAC-Publication-
No.-1200-Growing-Bull-Minnows-for-Bait.pdf
Auburn University Marine Extension and Research Center http://www.extension.org/mediawiki/files/2/24/
Growing_Bull_Minnows_in_Alabama.pdf
Dr. Cortney Ohs (University of Florida) http://miami-dade.ifas.ufl.edu/environment/documents/
aquaculture/Ohs_Marine%20Baitfish_Overview.pdf