Channel catfish is the leading aquaculture species in the United States. Over six hundred million lbs are produced annually, which represents about half of all aquaculture production in the United States.
Channel Catfish
The industry is centered in the Mississippi Delta region (Mississippi, Louisiana, Arkansas and also in west Alabama). These states account for more than 90% of total production.
Channel catfish is the third largest aquaculture species in North Carolina (behind rainbow trout and hybrid striped bass), with statewide production of about 4.6 million lbs in 2000.
http://www.agr.state.nc.us/aquacult/stattable.html
The Hybrid striper is a cross between a white bass and a striped bass. Of the three the hybrid grows the quickest. The original cross (Palmetto Bass) is a female striped bass and a male white bass (marone chrysops) . Was first produced in 1965 The recipical cross a female white bass and a male striped bass is the most common and preferred cross among aquaculturists because a male striped bass will mate readily with many females.The two hybrids are indistinguishable without biochemical tracing. Their horizontal stripes are dark like the stripers yet broken like the white. The body shape is intermediate. The Hybrid can withstand temperature extremes and lower disolved oxygen thus making it more suitable for pond culture than either of its parents. Almost every state in the southern region has hybrid striped bass producers, but most of the production is in Mississippi, North Carolina, Texas, Florida, Louisiana, and South Carolina. Annual production is approximately 600 metric tons. Fishery Biologists say that one of the most incredible facts is that within the first 12 months of life, a hybrid can reach 12 inches in length. Sometime in the middle of the second year, it will be 15 inches or longer and already at a legal size to keep. That's astounding growth.
World Record Hybrid Striped Bass
From Hybrid Striped Bass
The catfish industry was plagued during the late 1980s and early 1990s by price swings. There were nearly 2,000 farms in 1990, when the price to farmers was nearly $0.80 per lb. However, when the price dropped to .53 per pound (1991-92), this resulted in more than 25% of farms and 22 out of 30 processors going under. Today there are less than 1300 farms and less than 10 commercial-scale processors in the US.
Today, acreage in production and total lbs produced are both at an all-time high. Current trends in the industry is toward fewer, larger farms. An average catfish farm now has over one hundred acres of water surface area, representing an average total investment of $600,000 to $800,000 per farm.
When considering channel catfish production, it should be done large scale. You cannot make money on channel catfish in ten acres' ponds. Starting size should be somewhere in the range of fifty to sixty acres' of ponds, assuming that catfish production is an extension of an existing farm. Stand-alone catfish farm should probably be in the range of over 100 acres of water (the size of an average farm). More information is available at the NC Department of Agriculture for business planning services.
Presently two commercial-scale processors operate on the eastern seaboard, with both located in North Carolina. Carolina Classics Catfish in Ayden, NC and in business since 1986. Carolina Classics Catfish process the majority of catfish produced in the Carolinas and Georgia. A newer facility was recently completed near the Carolina Classics plant, and is owned and operated by Southern States Cooperative. (Also see http://en.wikipedia.org/wiki/Southern_States_Cooperative).
These plants are now in competition for available farm-raised live catfish produced in the Carolinas and surrounding region. (http://www.ncagr.com/markets/seafood/dns.htm)
Channel catfish (cost to the farmer) has remained around seventy to eighty cents on the pound, a record high for several years. Stabilization of price has resulted in expansion of catfish production in such traditional farming areas like the Mississippi Delta and western Alabama, including newer production areas in the southeastern coastal plains. With two processing plants in heavy competition driving prices upward, expansion in the industry is likely, particularly in the Carolinas. The value of the industry to the US economy is in the billion dollar range. Currently a shortage of good quality channel catfish fingerlings, especially in the newer production region of the southeastern US.
Only domesticated strains of channel catfish fingerlings should be used for commercial foodfish production. Wild fish produce fingerlings of inferior quality compared to farm-raised catfish. Wild fish have characteristics that make them well suited to natural conditions, but not in artificial hatchery troughs, fingerling holding tanks, and high-density static-water production ponds.
Domestication of Channel catfish has been ongoing over fifty years, meaning that domesticated strains are now many generations removed from those in the wild. With every generation, the surviving population that reaches the reproductive age is better adapted to the environment in culture facilities. Such fish are better able to withstand frequent handling, grow better on an artificial food supply, and reproduce with greater success than wild fish living under similar conditions. Domesticated fish are better able to withstand poor water quality and have greater resistance to diseases commonly encountered in culture facilities.
Many strains of domesticated channel catfish are available. Some better known strains are Kansas and Marion, which are hybridized to produce superior, fast-growing fingerlings. The USDA has sponsored selective breeding programs for channel catfish, which have produced strains like the USDA 103, developed by researchers at Mississippi State University.
Development and Evaluation - Since 1986, the USDA/ARS Catfish Genetics Research Unit in Stoneville, Mississippi has conducted research with the goal of enhancing the genetic potential of channel catfish. An important product of this research program has been the development and evaluation of a line of channel catfish tested under the experimental name, USDA 103. The USDA 103 line exhibited excellent growth compared to other catfish used by producers. The USDA and Mississippi Agricultural and Forestry Experiment Station (MAFES) began a joint release in February 2001 of the new catfish under the name National Warmwater Aquaculture Center 103 (NWAC 103). The following information summarizes the performance data gathered over six years of study and details the release of the line to producers.
Origin. The original stock of NWAC 103 catfish was obtained from the U.S. Fish and Wildlife Service National Fish Hatchery system. Sub-adult fish (1992 year class) were obtained in 1993 and reproduced in 1994 as 2-year old broodfish. Subsequent generations developed for joint release were produced and selected from the offspring of 2-year old spawners. Full-sibling families obtained in 1994 were selected for resistance to Enteric Septicemia of Catfish (ESC) and fish selected within families for growth rate were saved as future broodfish. Those offspring (1998 and 1999 year classes) were cultured in earthen ponds at the NWAC prior to release.
Distinguishing Genetic Information. In order to identify and maintain the genetic integrity of NWAC 103 channel catfish, a DNA fingerprinting system was developed. DNA can be quickly isolated from a blood sample or a small tissue sample and used to distinguish NWAC 103 catfish from non-NWAC 103 catfish. DNA markers have been characterized in three generations of catfish from the NWAC 103 line and compared to fry from 20 commercial fingerling operations in Mississippi, Alabama, Arkansas, and Louisiana, and wild fish from the Mississippi River. Based on information obtained from these markers on a random sample of 96 fish from a fingerling pond, the chance of any two contaminant fish being classified as a NWAC 103 catfish is 1 in 59 million. There is even a smaller chance, 1 in 100 million fish, that NWAC 103 fish would undergo mutation and become classified as non-103 fish.
msucares.com
This faster growing catfish variety is now available from regional distribution centers in all catfish production states.
Addtl. link:
Research to develop meatier, tastier, and faster growing catfish is paying off. Agricultural Research Service scientists at the Catfish Genetics Research Unit (CGRU) in Stoneville, Mississippi, have bred a new catfish variety—USDA 103—scheduled to be made available to catfish producers in February 2001. ARS will release the new catfish jointly from the Thad Cochran National Warmwater Aquaculture Center with the Mississippi State University Agricultural and Forestry Experiment Station, Mississippi State, Mississippi.ars.usda.gov
Selection of certain strains is a matter of personal preference, but should take into account the suitability for the environment. Any farmer wishing to utilize offspring from their own broodstock should exercise caution which minimizes negative effects from inbreeding. This may be accomplished when maximizing the number of breeding individuals in the broodstock population
Brood fish should be no less than four years, and weigh at least 4 lbs. Younger fish, which are generally smaller are unreliable spawners. Larger fish up to 10-12 lbs can be used, though older fish (which are generally larger), have a low fecundity (the number of eggs produced per pound, which ranges from 3000 eggs/lb in four-year-old fish and up to 2000 eggs/lb in large (older) fish.
Sexing the brood fish is important. Prior to, and during the spawning season, catfish display secondary sex characteristics that make the sexes more distinguishable than other times of the year. The head of a male catfish will be broader, more muscular, and will have a more rounded anterior than the female head, which will be narrower and have a more pointed snout. The female's urogenital area will be more swollen and may be reddish in color. Passing a small blunt probe over the urogenital area of the fish also indicates the gender. If it catches once in a single opening, it is probably a male. If it catches twice in a double opening, it is a female.
Once selection of a strain has been made and fish have been aged and sexed, the brood fish should be stocked into ponds at a ratio of about eight hundreds lbs per acre. This allows for additional growth of broodfish without need for thinning the population before the next spawning season. When brood fish ponds exceed 1200-1500 lbs of catfish per acre, water quality will suffer and spawning may slow or cease.
Broodfish should be fed 36% protein, floating feed for catfish. Feeding rates range from 2% of their body weight 4-5 days/week during the warm season and down to 1% of body weight once weekly, during cold months. Some catfish producers provide live forage for catfish broodstock in the form of fathead minnows or tilapia. Tilapia must be restocked each year since they die when water temperatures fall below 55F during cold months. High reproductive rates during summer provide small fingerlings in high numbers, which make excellent forage for brood catfish.
Egg production and transfer to hatchery
When water temperature rises to 75 F for at least five consecutive days (usually in early May for coastal North Carolina), channel catfish begin spawning. Preparations must be made in advance. Catfish do not spawn in ponds which have featureless bottoms. Wild catfish seek out hollow logs, areas that have been washed out, and other secure places to deposit eggs. The male remains to guard them until sometime after hatching.
The male of this Atlantic and Gulf Coast sea catfish takes full responsibility for caring for the marble-like eggs after he has fertilized them. How does he do this, in waters thick with predators? By carrying them in his mouth -- as many as 55 eggs, each one up to an inch in diameter, for a period estimated at six to eight weeks! As if that weren't enough, he then may carry the young around as well, until they double in size from their hatching length of two inches. The entire story is located at Enature.com
Gafftopsail Catfish male with eggs
© E. W. Gudger
Managed ponds have containers of various sorts placed in the pond for the brood fish to spawn. Containers will work if it has a volume of 10-15 gallons and has the proper dimensions to allow both the male and the female catfish to be inside at the same time. Containers should have a hole at one end large enough for a male catfish up to 10-12 lbs in size to freely enter and exit. Culturists use the old-fashioned milk jugs used by dairy farms, army surplus ammunition cans, nail kegs, earthenware jugs or large flower pots, even two five-gallon buckets fastened together, with a hole cut in one end. Plastic containers must be weighted down with bricks or a concrete block to keep them from floating. Containers should also have a float attached to them to make them easy to locate at the surface.
At regular intervals spawning containers should be placed around the perimeter of the pond, spaced twenty or thirty feet apart with its open end facing towards the center of the pond. First, when placing them in the pond, place them at depths of about two feet. Gradually move them into deeper water as water temperature rises. It is best to place the containers in the brood pond about seven to ten days before spawning is anticipated to commence. This allows time for the males to establish their territory.
Once spawning boxes have been positioned, each male attempts to claim a box of their own. They will viciously guard their box from other males, and entice females to enter their box to spawn. Eggs are laid in a single large gelatinous mass in the box, while the male fertilize the eggs. Once spawning is complete, males chase the female out of the box which prevents her and any other fish from entering the box while eggs incubate.
It takes about a week from the time of spawning, depending on temperature, for catfish eggs to begin to hatch. Spawning boxes should be checked for eggs only twice a week. Frequent disturbance may disrupt spawning activites. The male catfish guards the eggs, and he will likely need to be removed from the spawning box before eggs can be collected. Male catfish may attack and can inflict a severe bite, so caution should be used. The egg mass, will usually be stuck in one large lump to the bottom of the box, and may be removed with the use of a plastic spatula.
Eggs should be placed in water inside a small coolerm then taken immediately to the hatchery. When eggs are not immediately delivered to the hatchery, aeration should be provided to the water containing the eggs. Eggs require the same care as small fish. Water quality is important. Eggs should also be acclimated to the water they are being placed into before being transferred from one container to another.
- Unit 1, revised and edited class notes., January 17, 2006
No comments:
Post a Comment