Will Coker

us

Sciaenops Ocellatus Wide distribution spreading from the Western Atlantic to Mexico and S. America Found in sandy or muddy coastal waters and around estuaries Feed on squid, shrimp, crab, and small fish Max weight recorded was 94.6 lb 2-6 lbs is the best eating size

Economic Importance Usually sold in fresh or frozen filets or sold whole at $4.19- $4.63 per kg Also are raised for stock enhancement The major producers of red drum are China, Isreal, Ecuador, Martinique, and the U.S.

Life Cycle Spawn during September and October in the Gulf or the bay area Females can lay >1 million eggs The eggs incubate for around 24 hrs before hatching into the larval stage. The current washes the larva into estuaries where they settle in the grass meadows. Juveniles and young adults stay in the estuaries until they are sexually mature around yrs old

Reproduction in Captivity S. Ocellatus adapt well to captivity Broodstock: 4-6 fish of equal sex ratios are put into a tank to spawn This controlled spawning can be produced throughout the year by manipulating the temperature and photoperiods to mimic the fall months. The eggs are gathered and transferred to either rearing tanks or incubators to be hatched. Use open water and RAS systems.

Hatchery Nursery Once the eggs hatch the larvae (2.2mm) are usually housed in RAS systems. Generally ready to feed 3 days post hatch (dph) Inorganic and organic fertilizer are added to small ponds to build up the zooplankton. The larvae are put into these nursery ponds where they begin feeding on the zooplankton. Also put into intensive indoor systems where they feed on rotifers and pellet food. The larvae stay there until 30 dph where they then reach the juvenile stage.

Grow-out Juvenile s. ocellatus are grown in either cages or ponds Red drum fingerlings (0.2 g) are stocked at 1,000 fry/m 3. As the fish grow, they may be moved into larger cages and the density decreased to ~400 fry/m 3 Cages yield market sized fish (1kg) in a year and ponds usually take 11 months

Feeds Feeding Larvae feed on zooplankton rotifers, and Artemia Red drum juveniles require a diet containing percent protein and 12 percent fish meal for maximum growth. Usually fed fish pellets throughout their juvenile and adult life For optimum growth, fish should be fed approximately 3 to 5 percent of their body weight daily until they reach 1pound in which 2% will suffice. Can potentially double their weight each month FCR around 2.2:1

Water Chemistry Dissolved oxygen must be >4ppm for optimal growth The salinity should be kept around ppt Optimal temp. is 25-30C Juveniles cannot survive temperatures below 8C.

Red Drum Aquaculture Advantages Disadvantages They are well adapted to thrive in captivity Very hardy species Many offspring Not a picky eater Fairely easily grown and harvested Can be harvested within one year Can possibly contract and spread many diseases (mainly as exotic species) The young are sometimes cannibalistic in nature so grading is necessary Environmental waste