VIEWS: 27 PAGES: 6 CATEGORY: Fitness POSTED ON: 10/2/2011
Shrimp delicious, tonic and medicinal effects are higher. Its sweet, salty, and warm, impotence and kidney, supplement essence, through the power of milk. Where Jiubingtixu, shortness of breath, fatigue, not eating those, can be as nourishing food. People eat shrimp, there are physical strong body effect.
SRAC Publication No. 1201 VI April 2007 PR Bait Shrimp Culture Ryan L. Gandy1 The live bait shrimp industry in pound. This wholesale price However, live-haul trials of farm- the southeastern U.S. is dependent includes delivery from the shrimp raised, live bait shrimp showed on three shrimp species: the boat to the retail bait shop and so that commercial volumes (200 to Atlantic white shrimp (Litopenaeus it varies with the distances 500 pounds per shipment) could setiferus), the Gulf brown shrimp involved. Retailers who own their be successfully transported to (Farfantepenaeus aztecus) and the own shrimp boats may charge fish- retail bait shops with more than Gulf pink shrimp (F. duorarum). ermen as little as $7.00 per pound; 95 percent survival 24 hours after All three species occur along the in general, fishermen pay $10 to delivery. southern and eastern U.S. coasts $16 per pound for live bait shrimp from Texas through North (Fig. 1). Seed supply Carolina. The live bait shrimp The main impediment to bait industry within this extensive Live hauling bait shrimp shrimp aquaculture has been the coastal region is mostly a capture Wild-caught bait shrimp are trans- lack of consistent supplies of dis- fishery. Juvenile shrimp within a ported to market in oxygenated ease-free postlarvae (PL). Without size range of 150- to 60-count holding tanks at densities of 1 to them, both researchers and com- shrimp (3.0- to 7.5-g) are harvested 2 pounds per gallon of water. mercial aquaculturists have relied from inshore waters with trawling Mortality rates can be 25 to 50 per- on two methods of obtaining PL. gear. Recently, farm-raised, live cent within 24 hours of delivery. bait shrimp were introduced as an alternative to wild-caught shrimp. Bait shrimp market The wild product is highly season- al and the supply rarely meets demand, especially during the peak demand period of March through September. Shrimp are sold as both a live and a frozen product, with live shrimp commanding a premium price. The dockside (ex-vessel) price wholesalers pay to boat captains for live bait shrimp ranges from $2.75 to $4.00 per pound. The wholesale price bait retailers pay ranges from $7.50 to $14.00 per 1 Mote Marine Laboratory Shrimp Research Program, Sarasota, Florida. Figure 1. The most valuable consumers of live bait shrimp. Method I - sourcing wild, mated, these populations. Once a “high- plied with a combination of fresh gravid females health” wild population has been squid, adult enriched Artemia and isolated, it is induced to spawn bloodworms fed on a wet-weight This method entails leasing coastal and its offspring are tested for basis (20 percent of body weight shrimp boats during the full moons known viral pathogens. Once the per day, bw/d). Dry maturation of spring and early summer to offspring are determined to be diets are added to reduce the cost trawl the spawning grounds for “clean,” they are moved to a biose- of fresh food. mated, gravid (egg-bearing) females cure grow-out facility where they (Fig. 2). Once gravid females are Once acclimated to the maturation are raised to broodstock size. The system, females are unilaterally caught, they are either spawned in broodstock are then reproduced in individual tanks onboard the vessel ablated—a process in which one maturation facilities and their off- eyestalk is removed to induce mat- or transported to land-based spring are used to supply farmers spawning tanks. Each gravid uration. Ovarian development with PL. ensues within 72 hours and mating female is kept in an individual tank for 12 to 36 hours under dark con- The maturation and reproduction and spawning begin thereafter. ditions, at a temperature of about of broodstock occur in a climate- Broodstock ranging from 25 to 35 g 28 °C (82.4 °F), and at a salinity of controlled maturation system have a reproductive capacity of 30 to 35 ppt. After spawning, the (27 °C, 80.6 °F) with 14-hour light 100,000 to 250,000 eggs per spawn female is removed from the tank and 10-hour dark photoperiods and can spawn every 3 to 7 days. and the fertilized eggs hatch within (Fig. 3). Broodstock are kept in Fertilized eggs will hatch within 24 24 hours. 10.5- to 16.4-m2 (12-ft to 15-ft hours of fertilization at 28 °C diameter) maturation tanks at den- (82.4 °F). The nauplii are allowed Sourcing wild, mated, gravid sities of six shrimp per m2. During females is a cost-effective tech- to remain in hatching tanks until maturation, broodstock are sup- they metamorphose into the last nique for acquiring fertilized eggs, but it is not a reliable year-round production method. There also is a high risk of acquiring shrimp infected with viral pathogens that will jeopardize the biosecurity and sustainability of the farm. Method II– hatchery Developing and operating a biose- cure hatchery is both capital and labor intensive. However, a biose- cure hatchery ensures a sufficient year-round supply of PL for com- mercial operations. Healthy brood- stock must be developed and main- tained in a disease-free hatchery. The quantity of viral pathogen-free broodstock is limited. Researchers at the Mote Marine Laboratory in Sarasota, Florida, the Waddell Figure 2. Sourcing gravid females at night onboard a shrimp boat. Mariculture Center in Bluffton, South Carolina, and the Texas Agricultural Experiment Station in Corpus Christi, Texas, are isolating and developing “high-health” broodstock populations of the Atlantic white shrimp and Gulf pink shrimp. “High-health” broodstock are devel- oped through a process of quaran- tine and routine population testing using histological examination and a polymerase chain reaction (PCR) technique. Continuous screening of broodstock and offspring with these diagnostic tools detects organisms with specific pathogens so they can be eliminated from Figure 3. Maturation system. naupliar stage (N5). During the As a general rule, the acclimation farmers may increase production naupliar stages, no feed is provided temperature is changed by 1 °C densities to more than 2.5 kg/m2. as nauplii feed on their yolk sacs. (1.8 °F) every 15 minutes until it Intensive nurseries increase grow- Nauplii (N5) are then collected and matches the culture system tem- out survival by allowing farmers to transferred to larval-rearing tanks perature. Once temperature is stock larger shrimp (0.25 to 1.0 g) maintained at 28 to 29 °C (82.4 to adjusted, salinity can be changed into grow-out systems. In the tem- 84.2 °F) where they are fed marine by 1 ppt every 15 minutes until it perate climate of the southeastern algae (Chaetoceros gracilis and matches the culture tank salinity. U.S., greenhouse-enclosed nurs- Isochrysis galbana), live, newly If the pond has less than 15 ppt eries are used to give shrimp a hatched Artemia nauplii, and dry salinity and/or a temperature of head start in early fall (Fig. 4). A larval and postlarval diets, depend- less than 20 °C (68 °F), it is “head start” nursery is an effective ing on the stage of development advisable to use a nursery phase way to increase the number of and the dietary needs of that stage. and stock older, heartier juveniles crops each year and have better Shrimp larvae go through six larval later on. control over production by stock- stages over a 9-day period in the ing known quantities of heartier larval-rearing tank before they Zero exchange juveniles. In regions where early metamorphose to a postlarval (PL1) intensive nurseries spring temperatures are cooler stage. The entire larval cycle from Intensive nurseries (1,000 to than 20 °C (68 °F), greenhouse N5 until the shipment of the PL8-13 50,000 PL/m2) with biomass nurseries are essential so that the lasts 17 to 22 days, depending on capacities of 2 to 4 kg/m2 operated crop can be held until water in the the age of the PL requested by the under zero exchange have become grow-out system warms up. farm. In general, farmers request an important tool for shrimp PL8 - PL13 for stocking production Nursery management farmers. Zero exchange nursery systems. systems can have survivals of Nursery culture water is main- more than 80 percent and a har- tained at a temperature of 28 to Shipping post-larvae vest biomass of 1 to 7 kg/m2, 29 °C (82.4 to 84.2 °F), a dissolved Post-larvae are removed from lar- depending on the skill of the oxygen level of 5 to 7 mg/L, a pH val-rearing tanks and concentrated management and the investment of 7.5 to 8.5, and a Secchi depth of for counting, packing and ship- in capital infrastructure (filters 25 to 30 cm. Ten to 14 days before ping. Shrimp PL are shipped at and oxygenation). Basic systems PL arrive from a hatchery, the cul- densities of 1,000 to 2,000 per L in consist of a green house enclo- ture tanks are filled with seawater polyethylene bags containing sea- sure; a 20- to 60-mil, high-density, (20 to 35 ppt). Then the water is water (30 to 35 ppt) that is saturat- polyethylene (HDPE) liner; a sand sterilized with sodium hypochlo- ed with oxygen and cooled to or bead filter; a regenerative rite (household bleach at 10 ppm) 18 °C (64.4 °F) before packing. blower for aeration; a propane or to prevent the introduction of The bags are usually packed in electric heat source; and oxygen pathogens from incoming waters. insulated foam coolers to maintain injection for large biomasses The treated culture water is temperature during shipping. Some (more than 2.5 kg/m2) and emer- allowed to sit for 24 hours without farmers save on the high cost of gencies. With increased experi- aeration to prevent a rapid reduc- freight by transporting high densi- ence and capital expenditure, tion of chlorine. During this period ties of PL (more than 1 million) in live-haul trucks with oxygenated tanks. Acclimation When a PL is at least 8 days old (PL8), it is sufficiently robust to handle the stress of transport and acclimation. The culture system must be more than 15 ppt salinity and warmer than 20 °C (68 °F) for the acclimation to proceed. Acclimation is accomplished in small, temporary tanks near the pond (direct stocking) or in a nurs- ery tank (a temporary tank for holding animals before they are released into the grow-out system). During acclimation, the density of shrimp is more than 500 per L. Pure oxygen is provided to the Figure 4. Intensive greenhouse nursery at Mote Marine Laboratory. tanks and bags during acclimation. the chlorine concentration will nursery cycle as the biomass pH higher than 7.5, and a Secchi remain above 1 ppm to provide the increases to more than 2.5 kg/m2. depth of 25 to 30 cm. Ponds may necessary disinfection level. After be disinfected with 10 ppm chlo- 24 hours, the water is heavily aer- Nursery harvesting rine upon filling to kill viral vec- ated to remove residual chlorine, a Nurseries should be equipped with tors and pathogens that may be process that takes 3 to 5 days a harvest basin and constructed to introduced from wild sources. depending on temperature and drain fully. Harvest begins in the However, this may not be econom- organic load. The dechlorinated early morning when the nursery is ically feasible, given the cost of culture water is then fertilized and drain-harvested into a harvest chlorine and size of the operation. inoculated with algae. basin. Shrimp are removed from Whether or not a pond is dechlori- The raceway water is fertilized the harvest basin with collection nated, incoming water should with inorganic fertilizer (5 mg/L nets and transferred to hanging bal- always be filtered with 200-micron urea, 0.5 mg/L triple super phos- ances for group weights. During socks. phate and 1 mg/L sodium metasili- the weighing process, a periodic Ponds are filled and fertilized with cate). Water from an adjacent race- sub-sample of the population is 200 pounds per acre of cottonseed way with a healthy algal bloom is weighed and counted to determine meal 5 to 7 days before stocking. generally used to inoculate the new the average weight of the popula- Culture water from an established raceway with algae. Moderate aera- tion. The average weight and total pond is transferred into the new tion is maintained in the raceways biomass are used to determine total pond to inoculate it and expedite as the algal bloom develops over shrimp harvested and the survival the algal bloom. The algal bloom the next 7 days to a Secchi reading in the raceways should be well established (25 to of approximately 25 to 30 cm. It is Total shrimp harvested = Total biomass 30 cm Secchi depth) when shrimp important to check pH as the weighed ÷ Average weight are stocked. bloom develops. The high pH Once in the ponds, shrimp are fed (higher than 8.75) created by the Survival rate = (Total shrimp harvested ÷ Number of shrimp stocked) x 100 % a 30 to 35% protein feed at rates of algal bloom can be a problem for 3 to 6 percent bw/d. Feed trays are young PL. To counteract it, carbon The shrimp are rapidly weighed used to prevent overfeeding. The dioxide from a compressed CO2 and placed in hauling tanks water must be aerated at a rate of cylinder is added to the culture equipped with oxygen injection for 10 to 18 hp per acre (Fig. 5). The water with an air stone to decrease transportation to the pond. general pond culture period for the pH to 8.0 before PL are 90-count shrimp (5.0 g) is 90 days. stocked. Nursery aeration is then Intensive pond production Ponds stocked with 0.5-g shrimp at reduced to a minimum and PL are a density of 200 per m2 can grow For optimum production, pond acclimated and stocked in the nurs- at a rate of 0.5 g per week, have water should have a temperature of ery system. 70 percent survival, and produce 28 to 29 °C (82.4 to 84.2 °F), a Nursery feeds salinity of 20 to 30 ppt, a dissolved up to 7,000 kg/ha (6,160 lbs/ac) of oxygen level higher than 5 mg/L, a market size (5.0-g) live bait shrimp. A diet of newly hatched Artemia (five nauplii/L/day) and dry post- larval feed (50% protein) is fed at 10 to 25 percent of the total body weight per day (bw/d) for the first 5 days after stocking. Then the feed rate is reduced to 7.5 percent bw/d and the feed is changed to a 40% protein crumble #0 feed. The crumble size is gradually increased (0, 1, 2, 3 and 4) as the shrimp grow. Shrimp feed is provided at 7.5 percent bw/d for days 6 through 14, then reduced to 6 per- cent bw/d for the remainder of the culture period. Nursery growth rate Under intensive nursery culture, native shrimp have grown from a PL10 to 0.5 g in 50 to 60 days. Supplemental oxygen and periodic filtration (using a sand or bead fil- Figure 5. Intensive pond production at the Texas Agricultural Experiment ter) are necessary to complete the Station in Corpus Christi, Texas. Pond harvesting Bait shrimp de Garza, Yta, D.B. Rouse and D.A. Davis. 2004. Influence of Shrimp are harvested in the early aquaculture information nursery period on the growth morning when the temperature is and survival of Litopenaeus low. A seine can be used to manu- Contacts by state vannamei under pond produc- ally harvest the pond, though this tion conditions. Journal of the method is labor intensive. Another Alabama World Aquaculture Society method uses a hydraulic fish D.A. Davis 35:357-35. pump attached to the harvest Department of Fisheries and Allied basin to drain-harvest the pond. Aquacultures, Auburn University Hanson T.R., R.K. Wallace, L.U. Harvested shrimp are rapidly Hatch and W. Hosking. 1999. weighed in small batches (less Florida Coastal Alabama recreational than 35 pounds each) before being R. L. Gandy live bait study, Report on the loaded into a hauling truck. The Mote Marine Laboratory Shrimp 1997 and 1998 Alabama live hauling truck is equipped with Research Program, Sarasota bait market surveys. Report oxygen injection to maintain satu- prepared for the Auburn rated oxygen conditions (more Mississippi University Marine Extension than 10 mg/L) during transport. T. R. Hanson and Research Center, 4170 The temperature is also lowered to Department of Agricultural Commander’s Dr., Mobile, about 20 °C (68 °F) to reduce Economics, Mississippi State Alabama. AUMERC 00-1. 30 stress. University pp. Farmers who harvest and sell live South Carolina Mays, R., J.A. Venero, D.A. Davis, shrimp to wholesalers at pond D.B. Rouse and I.P. Saoud. (in C.L. Browdy press). Nursery protocols for bank can expect prices of $4.50 to South Carolina Department of the rearing of the brown $5.50 per pound. Farmers who Natural Resources shrimp, Farfantepenaeus invest in hauling trucks and equip- ment can expect to receive more Texas aztecus: effects of stocking than $7.50 per pound for deliv- density, salinity and EDTA on T. M. Samocha growth and survival. Journal of ered shrimp. Texas Agricultural Experiment Applied Aquaculture. Station Shrimp Research Program Other culture systems Sandifer, P.A., J. S. Hopkins, A.D. Since the mid 1990s, researchers Selected readings Stokes and C.L. Browdy. 1993. have been developing super-inten- Preliminary comparisons of Cohen, J., T.M. Samocha, J.M. Fox the native Penaeus setiferus and sive, closed-recirculating shrimp and A.L. Lawrence. 2005. production systems. Recent Pacific Penaeus vannamei white Biosecured production of juve- shrimp for pond culture in advances in this technology have nile Pacific white shrimp in an made it possible to produce South Carolina. Journal of the intensive raceway system with World Aquaculture Society shrimp year round under high limited water discharge. density conditions (3 to 7 kg/m2). 24:295-303. Aquacultural Engineering 32(3- These systems are still in the 4):425-442. Samocha, T.M., B.J. Burkott, A.L. research and development phase Lawrence, Y.S. Juan, E.R. so capital and operating costs are Davis, D.A. and C.R. Arnold.1998. Jones and D.A. McKee. 1998. much higher (more than $3.50 per The design, management and Management strategies for pound) than with pond production production of a recirculating production of the Atlantic methods ($1.25 to $2.50 per raceway system for the produc- white shrimp Penaeus setiferus pound). The economic feasibility tion of marine shrimp. as bait shrimp in outdoor of these production systems is cur- Aquacultural Engineering 17:193- ponds. Journal of World rently limited to markets where 211. Aquaculture Society 29:211-220. prices are consistently high (more Gandy, R.L. 1997. U.S. national Samocha, T.M. and R. Gandy. than $5.00 per pound). Super- live bait shrimp market survey. 2000. Protocol for nursery intensive production systems are Master’s thesis, Texas A&M raceway. Acuacultura del marginally profitable when the University-Corpus Christi, Ecuador 39:72-77. price falls below $5.00 per pound. Corpus Christi, Texas. These systems are not economical- Zajicek, P., D. Zimett, C. Adama Gandy, R., T.M. Samocha, E.R. and A. Lazur. 1997. Live bait ly feasible when there is consider- Jones, and D.A. McKee. 2001. shrimp market analysis and able competition or profit margins The Texas live bait shrimp mar- farm enterprise budget. are low, but they do show promise ket. Journal of Shellfish Fisheries Bureau of Seafood and for year-round production or for 20(1):365-367. Aquaculture. Florida facilities that must be located inland in biosecure areas. Department of Agriculture and Consumer Services. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Southern Regional Aquaculture Center or the Cooperative Extension Service is implied. SRAC fact sheets are reviewed annually by the Publications, Videos and Computer Software Steering Committee. Fact sheets are revised as new knowledge becomes available. Fact sheets that have not been revised are considered to reflect the current state of knowledge. The work reported in this publication was supported in part by the Southern Regional Aquaculture Center through Grant No. 2003-38500-12997 from the United States Department of Agriculture, Cooperative State Research, Education, and Extension Service.
Pages to are hidden for
"Bait Shrimp Culture"Please download to view full document