Low-cost experimental unit and growth medium for testing soil effects on shrimp culture     

Gad Ritvo  Joe B Dixon  Tzachi M Samocha  Addison L Lawrence  William H Neill 《Aquacultural Engineering》1998,18(4):245-249

PVC pipes, 10 cm in diameter and 46 cm long, sealed at one end and filled with 18 ppt of artificial seawater and a 6-cm layer of substrate, were tested as experimental units for the culturing of penaeid shrimp. The growth substrate was prepared by mixing 70% quartz sand, 24% Georgia kaolin, 5% Gonzales bentonite and 1% Bermuda grass hay. One juvenile Penaeus vannamei was placed in each container and shrimp weight gain was monitored. In the first study (four replicates), shrimp grew to 8.15 g within 8 weeks at a rate of ≈1 g week⁻¹ with no mortality; thereafter, growth decreased and 25% mortality was observed. In the second study (seven replicates), the average weight of shrimp was 8.66 g in 10 weeks, with 29% mortality occurring between the seventh and eighth week. Experimental unit cost was $3.30.  相似文献   

Accumulation of Chemical Elements in Texas Shrimp Pond Soils   总被引：2，自引：0，他引：2  

Gad  Ritvo Joe B.  Dixon Addison L.  Lawrence Tzachi M.  Samocha William H.  Neill Michael E  Speed 《Journal of the World Aquaculture Society》1998,29(4):422-431

Abstract— This study evaluated changes in chemistry of shrimp pond soils over one production cycle. Several soil nutrients, pH, organic matter, and total soluble salts were analyzed in the upper 10 cm of pond-bottom soil on two Texas shrimp farms in two consecutive years. Soil concentrations of S, P, Ca, Mg, K, Na, Mn, and Zn increased from one year to the next, S increased by 400 ppm. Organic matter did not accumulate. The pH decreased in all pond soils, owing perhaps to the oxidation of organic matter and/or inorganic compounds. There was no statistical difference in shrimp yield between the two consecutive years. These results indicated that the accumulation of S and soluble salts derived from seawater and feed should be monitored and evaluated to prevent excessive chemical element loading of pond soil and discharge water.  相似文献   

Use of the Nematode Panagrellus redivivus as an Artemia Replacement in a Larval Penaeid Diet     

James M.  Biedenbach  Linda L.  Smith  Tamara K.  Thomsen Addison L.  Lawrence 《Journal of the World Aquaculture Society》1989,20(2):61-71

Penueus vannumei larvae (P₂ through M₃) and early postlarvae (<24 h old postlarva) were fed diets consisting of algae-only, nematodes ( Panugrellus redivivus ) plus algae or Artemia plus algae. Growth (dry biomass gain) of second and third stage protozoea larvae fed the nematodealgae diet was significantly better than that of larvae fed the Artemia-algae diet. From the first mysis through the postlarval substage (<24 h old), growth of shrimp fed the nematodealgae diet equalled that of larvae fed the Artemia-algae diet. All larval substages fed nematodes plus algae accumulated significantly greater biomass than those fed a diet of only algae. Survival and percent metamorphosis of larvae fed nematodes plus algae did not differ significantly from that of larvae fed either Artemia plus algae or algae alone. A nematodealgae feeding regime, which potentially yields growth, survival and metamorphosis equal to that obtained on the standard Artemia plus algae regime, is proposed for P. vannamei .  相似文献   

BUDGET ANALYSIS OF SHRIMP MATURATION FACILITY     

Michael Johns  Wade Griffin  Addison Lawrence  David Hutchins 《Journal of the World Aquaculture Society》1981,12(1):104-109

Shrimp maturation and reproduction has long been one of the hurdles that must be surmounted to make shrimp farming commercially feasible. Nauplii are now successfully being produced and the commercial feasibility of their production is investigated in this study. The generalized budget simulation model for aquacultural facilities recently developed at Texas A&M University was used for the analysis. An annual budget was estimated to determine costs, returns and profit. Annual cash flow was generated for a 10-year planning horizon. Opportunity cost, initial investment, costs and break-even quantities and prices were also determined.  相似文献   

Evaluation of Methods for Determining In Vivo Digestion Coefficients for Adult Red Swamp Crayfish Procambarus clarkii     

Paul B.  Brown  Christopher D.  Williams  Edwin H.  Robinson  Dean M.  Akiyama Addison L.  Lawrence 《Journal of the World Aquaculture Society》1986,17(1-4):19-24

Adult red swamp crayfish ( Procambarus clarkii ) were held in fecal collection chambers and fed common feedstuffs isosubstituted in experimental diets. Apparent dry matter digestibility (ADMD) and apparent crude protein digestibility (ACPD) coefficients were determined by the total collection and indicator (chromic oxide) methods. Feedstuffs tested were menhaden fish meal, soybean meal, alpha-soy protein, casein, gelatin, wheat bran, rice bran, wheat gluten, shrimp meal, crab chitin, cellulose, squid meal, corn starch and diatomaceous sand. Rate of consumption of plant feedstuffs was generally higher than feedstuffs of animal origin. Consumption of fish meal and shrimp meal was low (0.59 and 0.44% body weightlday, respectively). Fecal chromium concentrations were lower than chromium concentrations of experimental diets and precluded calculation of realistic coefficients by the indicator method. Analysis of refused feed samples indicated that crayfish did not consume the indicator in the same proportion as the remainder of the diet; therefore, the total collection method was judged the better approach to determining digestion coefficients. ADMD and ACPD coefficients of plant feedstuffs were generally higher than coefficients determined for animal feedstuffs. ADMD coefficients indicated substantial carbohydrate digestion by crayfish.  相似文献   

Effect of Feed Protein and Carbohydrate Levels on Feed Intake,Growth, and Gonad Production of the Sea Urchin,Lytechinus variegatus     

Hugh S. Hammer  Mickie L. Powell  Warren T. Jones  Victoria K. Gibbs  Addison L. Lawrence  John M. Lawrence  Stephen A. Watts 《Journal of the World Aquaculture Society》2012,43(2):145-158

In this study, we evaluated protein and carbohydrate levels in cold‐extruded dry diets. Sea urchins (12.6 ± 0.12 SE g wet weight, 29.5 ± 0.11 SE mm diameter) were collected from St. Joseph Bay, Florida (30°N, 85.5°W), and transported to the Texas Agrilife Research Mariculture Laboratory in Port Aransas, Texas. Urchins were held individually in replicated enclosures within a recirculating seawater system (32 ± 2 ppt and 22 ± 2 C). Urchins (n = 16urchins) were fed diets that differed in protein : carbohydrate levels (31:33%, 25:39%, 21:44%, and 17:47% dry weight) for 12‐wk. Survival was 100% in all diet treatments. Urchins fed the 31:33% protein : carbohydrate diet consumed less feed, more dry protein, less dry carbohydrate, less energy, and had lower feed conversion ratios than urchins fed other diets. Urchins fed the 31:33% protein : carbohydrate diet had larger test diameters, total wet weights, production efficiencies, and gonad production efficiencies than urchins in the other diets. Weight gain varied directly and significantly with protein intake. Sufficient energy was available for maximum weight gain as protein was spared. Growth rates and production efficiencies for the urchins in this study were higher than in previous feeding studies with adult Lytechinus variegatus.  相似文献   

Fertilization and Development of Eggs of the Sea Urchin Lytechinus variegatus Maintained on an Extruded Feed     

Sophie B.  George John M.  Lawrence Addison L.  Lawrence John  Ford 《Journal of the World Aquaculture Society》2000,31(2):232-238

Sea urchin eggs are used extensively as models for studies in developmental and molecular biology. Developing aquaculture techniques and facilities for sea urchins would facilitate their use for this purpose and for production of young sea urchins for stock enhancement. A basic requirement for the aqua-culture of sea urchins is the availability of a feed that predictably produces eggs of a consistent, high quality. We tested an extruded feed with Lyrechinus variegatus for this purpose. Lytechinus variegatus (mean horizontal diameter 55 mm, 75 g wet weight) were collected in April 1998. Nine individuals were maintained in each of four aquaria with closed, recirculating filtered sea water. They were fed approximately 1 g extruded feedindividual per week. All feed was consumed. The mean weight of the sea urchins changed little with this feeding regime. The sea urchins spawned spontaneously on a monthly basis during water changes. Four females in February and one in March were spawned by injection with potassium chloride. Fertilization was 99–100% successful in each case. Egg diameters from these spawnings and a spontaneous spawning in April ranged from 102 × 6 to 128 × 1 μm. Gastrulation occurred in <20 h and metamorphosis after 22 to 37 d. Newly metamorphosed juveniles ranged in size from 435 × 38 to 473 × 56 μm. Egg size, larval size, the chronology of embryonic and larval development, and size of newly metamorphosed juveniles are similar to those obtained from field individuals reported in the literature. These results indicate that a predictable production of high quality eggs by sea urchins under controlled conditions in the laboratory with a prepared feed is feasible.  相似文献   

Trawl catch composition in relation to Norway lobster (Nephrops norvegicus L.) abundance on the Farn Deeps grounds, NE England     

M.C. Bell  J.M. Elson  J.T. Addison  A.S. Revill  D. Bevan 《Fisheries Research》2008,90(1-3):128-137

Management of fisheries directed at a particular species (the target) is often complicated by the capture of other species (the bycatch), each of which may be subject to competing management objectives. Optimal management depends upon a good understanding of how catches of the target species vary in relation to bycatch of other species of commercial and conservation concern. This paper considers the composition of trawl catches taken on a Norway lobster (Nephrops norvegicus) ground off the NE coast of England, examining the factors that determine catch rates of Nephrops and various commercial finfish species taken as bycatch. We describe the results of a trawl survey undertaken using four commercial vessels deploying standard commercial gear. Only about 19% of the variance in Nephrops catch rates could be accounted for by variations in local density, as measured independently by underwater television survey of Nephrops burrows. Variations in Nephrops catch rates were dominated by changes over time, particularly in relation to tidal state. Five commercial bycatch species were taken alongside Nephrops in significant quantities. Catch rates of haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus) and lemon sole (Microstomus kitt) varied independently of Nephrops, whereas catches of cod (Gadus morhua) and plaice (Pleuronectes platessa) were inversely related to Nephrops. We conclude that it is possible for the commercial Nephrops fishery to use spatial and temporal targeting to maximise catches of N. norvegicus whilst minimising the bycatch of some fish species. If catch statistics are used to identify Nephrops-directed fishing métiers for fishery management purposes it is vital that data are examined at the level of individual hauls or fishing trips. Aggregation of data at a higher level risks obscuring the effectiveness with which the fishery is targeted at Nephrops.  相似文献   

Assessment of fruit fly (Diptera: Tephritidae) management practices in deciduous fruit growing areas in South Africa     

Aruna Manrakhan  Pia Addison 《Pest management science》2014,70(4):651-660

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Dietary effect of fish oil and soybean lecithin on growth and survival of juvenile Litopenaeus vannamei in the presence or absence of phytoplankton in an indoor system     

Dagoberto R Sánchez  Joe M Fox  Delbert Gatlin III  Addison L Lawrence 《Aquaculture Research》2014,45(8):1367-1379

This study was conducted to evaluate whether phospholipids have the potential to reduce the level of dietary fish oil inclusion in shrimp feeds in the presence and absence of phytoplankton. To do so, weight gain of juvenile Litopenaeus vannamei stocked at 80 shrimp m^?2 fed different dietary levels of fish oil and soybean lecithin was determined. Six experimental 35% protein diets were formulated to contain 1%, 2% or 3% fish oil combined with either 1% or 4% soybean lecithin. Dietary effects were evaluated using a ‘clear‐water culture system’ without the presence of microalgae in 40‐L aquaria and a ‘green‐water culture system’ in 1.9‐MT tanks. After an 8‐week feeding period, shrimp cultured in both systems and fed diets containing 4% soybean lecithin had greater weight gain than those fed 1%. Thus, diets supplemented with phospholipids improved the efficiency of lipid utilization for growth: diets containing 1% fish oil in combination with 4% soybean lecithin can be used as a cost‐effective combination for commercial shrimp culture feeds. Weight gain in the green‐water system was 1.5–1.7 times greater than that for shrimp reared under clear‐water conditions, suggesting that phytoplankton contributes to shrimp growth through the continuous provision of nutrients.  相似文献