TROUT (Oncorhynchus mykiss)

Rainbow trout (Oncorhynchus mykiss) are native to western North America and have been cultured for over 100 years. Over the last several years, the U.S. trout industry has been relatively stable in numbers of operations and value of sales and output. The state of Idaho produces the most trout in the United States (41 million pounds sold in 1998). North Carolina leads trout production (3.5 million pounds sold in 1998) in the southeastern states.

Kentucky has a small, but well established commercial rainbow trout industry with seven year-round farms producing approximately 400,000 pounds. The U.S. Fish and Wildlife Wolfe Creek National Fish Hatchery, located near Jamestown, Kentucky, also annually produces about one million trout for stocking as sportfish.

Kentucky trout production is limited by the availability of large freshwater springs which provide gravity-fed water in adequate quantity. These springs must have a year round supply of contaminant free water. To insure trout survival, water temperature should rarely exceed 70 degrees F. For a small trout facility to provide supplemental income, flow rates of approximately 350-500 gallons per minute would be required.

Small scale, full time trout farming would require flow rates of 1,000-2,000 gallons per minute. Most Kentucky trout farms are equipped with egg incubation facilities. Eyed eggs are typically purchased from commercial brood fish farms located in the western United States.

Trout and trout eggs should be certified to be free of diseases. Commercial culture occurs primarily in concrete raceways. Large volumes of water flow via gravity through a series of 4-8 raceways and is discharged into a receiving stream. Densely stocked fish are supplied with cold water which is rich in dissolved oxygen.

The water flow removes wastes from the culture unit and is replenished with oxygen when spilled into the next raceway. The water flow rate, water chemistry, temperature, size of fish, and the rate of feeding determines the volume of fish that can be produced in a particular raceway system. Average values are 20-40 pounds of fish per gallon per minute flow rate per year.

Trout may also be stocked in ponds during late fall (October or November) at a rate of 1000-1200 fish per acre in ponds which allow seining and do not contain largemouth bass. During the winter, trout may also be grown in suspended cages and net pens.

Trout, 8-10 inches in length are stocked in ponds, cages or net pens, in order to reach marketable size by spring (March or April). Six fish may be stocked per cubic foot of volume of a cage or net pen.

Currently, production and marketing research is underway to investigate profitable alternative water sources for growing trout. These would include waters associated with coal mining operations in eastern Kentucky. South Eastern Community College in Cumberland, Kentucky has been developing a trout production demonstration site as a result of a KDA Value-added Grant.

S. E. Community College estimates there may be as many as 500 suitable trout production sites in Harlan, Bell, and Letcher Counties using water from abandoned deep coal mines. Grow-out culture and test marketing of winter, pond-raised trout is currently being conducted in fallow freshwater shrimp ponds.

However, the high cost of stocker trout, feed, and poorly developed markets contribute to uncertain profitability of seasonal trout production. Efforts are underway to provide lower cost, advanced trout fingerlings for winter stocking.

The KAA has applied for and been awarded a KDA Value-added Grant to contract with a trout producer to supply a lower cost source of Kentucky raised fingerlings. Cooperative purchase of larger feed shipments will be organized to reduce costs. Test marketing of small volumes of fresh trout is being conducted.

Article Source:

http://www.ksuaquaculture.org/Species/Trout.htm

TILIPIA (Oreochromis niloticus)

Several species of tilapia and their hybrids are farmed throughout the world. The nile tilapia (Oreochromis niloticus) is a species commonly farmed in the United States. There is evidence to suggest the Egyptians raised tilapia in ponds over 3,000 years ago.

Tilapia are also called "Saint Peter's Fish" because it has been said that they were the fish Peter caught when Christ told him to cast out his nets in the Sea of Galilee.

Tilapia have several attributes which make them attractive as a culture species: high tolerance of poor water quality and crowding, good performance on commercial catfish feed (32% protein), a high degree of disease resistance, and a mild flavored, white flesh.

Because of their tolerance to crowding and poor water quality, tilapia are well suited to cage culture and recirculating systems. Research has also shown that in addition to controlling filamentous algae, tilapia stocked in channel catfish ponds can help control off-flavors by eating blue-green and other large planktonic algae.

Tilapia have a good growth rate. A 2 to 4 ounce tilapia fingerling can reach 3/4 pound. by the end of a temperate growing season. Tilapia performance is best in a temperature range of 72-90ºF. Growth and feeding slow when water temperatures drop below 70ºF.

However, tilapia are cold intolerant and die when water temperatures are lower than 45-55ºF. Blue tilapia will survive in lower water temperatures (above 45ºF) than most other species of tilapia.

The pond production season in Kentucky would begin in late April and end just before the middle of October. Therefore, tilapia marketing would be seasonal and within a week or two of the same time each year. Indoor culture of tilapia in recirculating systems could extend the growing season.

Article Source:

http://www.ksuaquaculture.org/Species/Tilipia.htm

STURGEON (Ascipenser fulvescens )

Sturgeons are found only in the northern hemisphere. Like the paddlefish, sturgeon are without bones and the processed roe (caviar) is highly valued. Of the 26 sturgeon species found in the world, the main sources of caviar for global demand are only from four sturgeon species from the Caspian Sea:
a) beluga (Huso huso)
b) Russian sturgeon or osetra (Acipenser gueldenstaedti)
c) stellate or sevruga (A. stellatus)
d) ship (A. nudiventris)

Reports have shown that there is a major decline in sturgeon stocks within the Caspian Sea. Farming technologies have been established for some commercially valuable species. Sevruga and Russian sturgeons are being farm-raised in ponds in Europe.

In the United States, white sturgeon have been farmed-raised on one farm in California which has recently begun to market meat and caviar. The farming system uses a recirculating system requiring feeding prepared diets, intensive management, and high capital and operating costs, especially for mature females for production of caviar.

Shovelnose sturgeon, found in the Mississippi drainage, have recently drawn much attention as a domestic caviar in the United States. The use of Russian sturgeon that can be farm-raised in ponds and co-exist with other fish species should be evaluated in Kentucky.

Article Source:

http://www.ksuaquaculture.org/Species/Sturgeon.htm

PRAWN (SHRIMP)

Macrobrachium rosenbergii

The freshwater shrimp, or more properly, freshwater prawn, is a member of a large group of freshwater crustaceans found in many parts of the world. There are several species found native to the U.S., but most aquaculture efforts are concentrated on the Giant Malaysian Prawn (Macrobrachium rosenbergii) which is a native of southern Asia.

Culture efforts in the U.S. were initiated in Hawaii in the 1960s, South Carolina in the 1970s, and Mississippi in the 1980s. Despite these efforts, substantial concentrated production of this species has not developed. Large scale production has been hindered by relatively low production rates, size variability at harvest, and a relatively demanding process for producing seedstock.

Over the past five years interest in production of this animal has again increased due to an increasing demand for shrimp products, reduced supplies of shrimp (especially large sizes) due to serious disease problems in saltwater shrimp production, and increases in production rates for prawns based on new management and production practices.

Other factors producing increased interest in production include identified markets for live and fresh prawns in inland locations, the growing trend among consumers wanting to know of how their food was produced, and the discovery that prawns actually grow more rapidly at cooler temperatures.

Seedstock production for prawns normally begins with selection of broodstock at the harvest of production ponds in the fall. The number of females is based on anticipated production needs. Broods must be overwintered in tanks at greater than or equal to 70º.

Volume and added substrate in holding tanks should allow each brooder approximately two square feet of surface area. Broods should be fed a high quality marine shrimp diet or sinking salmonid pellet. Either should be supplemented with fish flesh and beef liver so that the females can store the proper nutrients in the egg yolks for the larvae to live on after hatching.

In Kentucky, production ponds are stocked in late May-early June with what are known as 60 day nursed juveniles (0.3-0.5 gram average weight). That is they have been grown for 60 days in freshwater after completing 30 days of larval development in brackish (salty) water.

This means prawns should be hatched from mid-February to mid-March to allow sufficient nursery time prior to pond stocking. Nursery tanks are normally much larger than larval tanks as stocking rates are reduced from approximately 200 per gallon in the larval tanks to 20 per gallon in the nursery tanks.

These tanks must also be provided with mesh substrate structures sufficient to produce 40 post larvae per square foot density. In the nursery phase, water temperatures are maintained at 78-82ºF and the prawns are fed trout starter feeds at a declining percentage of body weight.

Article Source:

http://www.ksuaquaculture.org/Species/Prawn(Shrimp).htm