bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Dietary Carbohydrate: Lipid Ratio on Growth and Body Composition of Hybrid Striped Bass
Authors: Nematipour Gholam R. , Brown Michael L. , Gatlin Delbert M. 
Published: April 2007

AbstractA study was conducted to determine the ability of juvenile hybrid striped bass, Morone crysops ♀× M. saxatilis ♂, to utilize dietary carbohydrate and lipid for energy. Four semipurified diets containing 35% crude protein were formulated to be isocaloric with various levels of dextrin and menhaden fish oil 50 the carbohydrate: lipid ratio (CHO:L) ranged from 2510 to 42:2.5. Diets were fed in triplicate to groups of hybrid striped bass initially averaging 1.5 g/fish in 38 L aquaria receiving a constant supply of hard (> 180 mg/L as CaCO3) freshwater for a period of eight weeks. Weight gain, feed and protein efficiencies were similar among all dietary groups. Hepatosomatic index (liver weight × 100/body weight), muscle ratio (whole muscle weight × 100/body weight) and condition factor were also similar, while intraperitoneal fat (IPF) ratio (IPF weight × 100/ body weight) was significantly (P × 0.05) increased as CHO:L decreased. Proximate composition of muscle did not show any effects of diet. However, dry matter and lipid of whole‐body increased significantly as CHO:L decreased; conversely whole‐body protein was significantly reduced. Moreover, liver glycogen significantly increased as CHO:L decreased. These data indicate hybrid striped bass are able to efficiently utilize carbohydrate for energy; and dietary lipid, which generally caused increased lipid deposition in various tissues, could be partially replaced with carbohydrate to improve fish quality and productivity.
Density‐Dependent Pond Growout of Single Year‐Class Cohorts of a Freshwater Crayfish Cherux tenuimanus (Smith) to Two Years of Age
Authors: Morrissy Noel M. 
Published: April 2007

AbstractPond growout of Cherax tenuimanus to two years of age provided data for mean crayfish weight, surviving density and distribution of individual sizes at intervals and final harvest for 12 single year‐class cohorts. Final mean size (47–156 g) was most significantly related to surviving density (4.5–0.7/m2). A hyperbolic model with a harvest date variable accounted for 89% of the variation in mean weight. The biological basis of this model is that the reciprocal of density, i.e., pond area per crayfish, represents food supply for a bottom‐dwelling crayfish. By incorporating the Richards growth function, the hyperbolic model can be more realistically fitted to include the limit to potential size at very low densities. The growth‐density relationship developed after an initial period of 300 days of low growth (to ∼ 10% of final size) and high mortality. Then, mean weight increased rapidly and density stabilized. Final cumulative production (1.401–3,922 kg/ha) and harvest biomass (1,110–2,991 kg/ha) both increased linearly with density. Survival of the total amount of crayfish produced was about 75% at harvest. Although cohort size distributions were positively skewed, the arithmetic mean size employed in the model was very closely and linearly related to the geometric mean of the lognormal distribution, The causal basis and assumptions of the growthdensity model are discussed in relation to resource sharing by individuals and the disproportionate influence of size‐related dominance behaviour.
Reporting Fish Growth: A Review of the Basics1
Authors: Hopkins Kevin D. 
Published: April 2007

AbstractAquaculturists typically report growth using absolute (g/d), relative (% increase in body weight), and specific growth rates (%d). Less frequently, von Bertalanffy Growth Functions (VBGF) are used. Each of these rates is a numerical representation of growth which assumes a specific relationship between size and time (linear, exponential, or asymptotic). Aquaculturists typically determine size at time throughout their experiments. Unfortunately, the intermediate data points are usually ignored when computing growth rates (except for VBGF) and the appropriateness of the method for calculating growth for a particular data set is not tested. This paper reviews the basis and computation of each of the growth rates in an effort to encourage aquaculturists to use the appropriate growth rates.
Recent Progress in Research and Development of Marine Cold Water Species for Aquaculture Production in Norway
Authors: Tilseth Snorre , Blom Geir , Naas Kiell 
Published: April 2007

AbstractThe paper reviews recent progress in larviculture of Atlantic cod and Atlantic halibut in different experimental enclosed seawater systems in Norway. More than 240,000 cod juveniles have been produced in a 270,000 m3 seawater pond. However, very promising production results of cod have been achieved in plastic enclosures with volumes > 100 m3. Halibut juveniles have been successfully produced in plastic enclosures and tanks by using natural zooplankton as food. The enclosure technique could be adapted to commercial scale production of juvenile halibut. However, scaling up experiments are necessary.
The Influence of Different Rotifer and Artemia Enrichment Diets on Growth, Survival and Pigmentation in Turbot (Scophthalmus maximus L.) Larvae
Authors: Støttrup Josianne G. , Attramadal Y. 
Published: April 2007

AbstractAn experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low‐HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids—HUFA). Seven tanks were set up for each diet. After the rotifer stage, approximately seven days after hatching, the larvae were fed newly‐hatched Artemia salina nauplii (AT‐1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tanks was further subdivided and the larvae fed Arternia nauplii enriched with one of four enrichment diets: Dry Selco, Protein Selco, ICES low‐HUFA or Super Selco. The rotifer enrichments had no significant effect on larval growth and survival. The nutritional value of the Artemia stage (day 13 to 26) was more important for the overall larval survival.
Larval Nutritional Physiology: Studies with Clarias gariepinus, Coregonus lavaretus and Scophthalmus maximus
Authors: Segner Helmut , Rösch Roland , Verreth Johan , Witt Ulrich 
Published: April 2007

AbstractStudies on the nutritional physiology of larval fish should provide the basis for defining the length of the larval period and for understanding the quantitative and the qualitative feed requirements of the larvae. For these purposes, it is necessary to perform both descriptive investigations on the ontogenesis of structures and functions as well as experimental investigations on adaptive strategies of the larvae under changing feeding regimes. In the present communication, examples of both approaches are discussed comparing three species: African catfish Clarias gariepinus, whitefish Coregonus lavaretus, and turbot Scophthalmus maximus.At the onset of exogenous feeding, the digestive system of all three species is sufficiently developed to ensure efficient utilization of live food, but not of dry food. A major event during the subsequent development is the differentiation of the stomach. Evidence exists that for turbot and catfish, a functional stomach is necessary to utilize dry feeds as efficiently as live feeds. Therefore, from a nutritional point of view, in those two species the larval period, during which a special larval diet has to be given, ends with the completion of stomach differentiation.The capacity of the larvae to acclimate physiologically to different nutritional conditions seems to be limited. Using general nutritional indices such as protease activity, RNA/DNA ratio, midgut cell height or nuclear diameter of hepatocytes, larvae of the three species show partly starvation symptoms when reared on dry food. This effect can be explained to some extent by quantitative considerations, i.e., lower food consumption and digestibility is less for dry diets than for live diets. The contribution of the qualitative factors involved in the different performance of larvae reared on dry or live food is presently not well understood. Future studies should: 1) investigate why utilization of dry diets depends on presence of the stomach; 2) define more precisely the quantitative feed requirements of larvae; and 3) search those diet‐induced qualitative differences of larval metabolism which affect growth performance.
Protein Synthesis in Juvenile Tilapia Oreochromis mossambicus
Authors: Houlihan D. F. , Pannevis M. , Heba H. 
Published: April 2007

AbstractA method for measuring protein synthesis has been developed for small juvenile fish. A flooding dose of [3H] phenylalanine (Houlihan et al. 1988b) was added to the water containing the animals. Using juvenile tilapia O. mossambicus of approximately 15 mg, stability of the phenylalanine free pool specific radioactivity was achieved within 10 h. A linear increase in the whole body specific radioactivity of protein‐bound phenylalanine occurred 3 h after [3H] phenylalanine was added to the water. In larger animals the flooding dose was injected into the peritoneum, and stable free pool phenylalanine specific radioactivities were achieved over 2 h. In the small fish the rate of protein synthesis exhibited a diurnal pattern. Scaling relationships for growth, protein synthesis and protein degradation were similar. The energy cost of protein synthesis in small juvenile animals, determined from the difference before and after the addition of the protein synthesis inhibitor cycloheximide, was close to the theoretical minimal cost.
Recent Advances in Nutrition of Penaeus monodon
Authors: Chen Houng‐Yung 
Published: April 2007

AbstractThis paper provides a brief summary of information on recent advances in the nutrition of Penaeus monodon. The nutritional requirements of P. monodon have been little known despite its importance in aquaculture. Recent findings indicate a noticeable difference between some important nutrient requirements of P. monodon and P. japonicus, the most studied shrimp species. For example, the thiamin requirement for P. monodon was estimated to be 14 mg/kg diet, while for P. japonicus it is 60‐120 mg/kg diet for juveniles and 40‐80 mg/kg diet for larvae. The same contrast was also observed in the requirements of riboflavin (22.5 mg/kg in juvenile P. monodon vs. 80 mg/kg in larval P. japonicus), niacin (6.4 mg/kg vs. 400 mg/kg) and vitamin C (2,000‐2,500 mg/kg vs. 10,000 mg/kg).Research efforts to understand the lack of ability for shrimp to effectively use dietary crystalline amino acids have resulted in the development of a microencapsulated amino acid that can be assimilated by P. monodon which is incapable of utilizing the essential amino acid in crystalline form. This development enables the quantification of requirements of the amino acid and other essential amino acids for shrimp. A study using cellulose‐acetate‐phthalate encapsulated arginine indicated that the arginine requirement of postlarval P. monodon is 5.47 g/100 g protein (2.50 g/100 g diet).Other aspects concerning the importance of digestive enzymes, dietary requirements of protein, carbohydrate, lipid and vitamin, energy and larval feeding for P. monodon were reviewed.
An Intensive Approach to Atlantic Halibut Fry Production
Authors: Holmefjord Ivar , Gulbrandsen Jon , Lein Ingrid , Refstie Terje , Léger Philippe , Huse Ingvar , Harboe Torstein , Sorgeloos Patrick , Olsen Yngvar , Bolla Sylvie , Reitan Kjell Inge , Vadstein Olav , ØIe Gunvor , Danielsberg Anne 
Published: April 2007

AbstractThe larval stage is regarded to be the main bottleneck of halibut production. Halibut eggs were obtained from captive broodstock both by stripping and by natural spawning. Artificial photoperiods were used to increase the total spawning season. Yolk sac larvae are presently produced either in small stagnant units or in large flow through systems. A major consideration is to avoid stress of the larvae, caused by mechanical disturbances of the larvae and by high bacterial load or high ammonia levels in the water.The experiments showed that halibut larvae began to ingest algae earlier than rotifers Brachionus sp. Supplementation of algae to first feeding tanks resulted in enhanced survival and growth rate of the larvae. Both rotifers and Artemia can be enriched with very high levels of highly unsaturated n‐3 fatty acids (n‐3 HUFA). Enriched live feed, containing high levels of n‐3 HUFA and total lipids, enhanced both survival and growth of the halibut larvae. The highest growth rates were obtained with wild zooplankton and addition of algae, but enriched cultivated feed combined with algae resulted in growth of the same magnitude as with wild zooplankton.
Manipulations of Shrimp Embryos: A Viable Technique for the Removal of the Hatching Envelope
Authors: Lynn John W. , Glas Patricia S. , Hertzler Philip L. , Clark Wallis H. , Green Jeffrdy D. 
Published: April 2007

AbstractThe hatching envelope elevated around the spawned eggs of penaeoidean eggs presents a formidable barrier for manipulation of the embryo. By spawning eggs into seawater containing 3‐amino‐1,2,4‐triazole and subsequently passing the eggs through Nitex screening approximately 45 min after spawning, the hatching envelope can be effectively removed with little or no damage to the embryos. The time and extent to which the envelope is removed can be varied. Embryos treated in this manner continue to develop and the method provides a new technique with which investigators can gain access to the surface of the egg or embryo.
Economic Evaluation of Different Stocking Densities for Various Sized in Texas
Authors: Lambregts Johannes A. D. , Thacker Sayra G. , Griffin Wade L. 
Published: April 2007

AbstractThere has been a trend toward intensification of shrimp farming in the U.S. FiCteen simulated farms were used to evaluate economies of scale and to compare three Penaeus vannclmei commercial production strategies: semi‐intensive, intensive, and very‐intensive. Large economies of scale were associated with each production strategy. Over the range of farm sizes considered, investment cost per hectare decreased approximately 50% and production cost decreased approximately 25%. Farms' returns were measured with Internal Rate of Return (IRR). When investment was greater than $0.75 million, the intensive strategy provided slightly better returns to the investor than semi‐intensive or very‐intensive strategies. At investment levels less than $0.75 million, the semi‐intensive strategy provided the highest IRR.
The Impact of Aquaculture Pond Engineering Design on the Returns to Shrimp Farms
Authors: Griffin Wade L. , Lambregts Johannes A. D. , Yates M. W. , Garcia A. 
Published: April 2007

AbstractThe effects of pond design on the internal rate of return of a 40 ha shrimp farm is evaluated. The influence of four pond construction parameters (pond size, pond shape, levee crown size and canal bank slope) on the total amount of earth moved and construction costs is determined using an engineering design model. The bioeconomic model, MARSIM, calculates returns to farms with the design modifications. Of the four parameters, the pond shape is the most influential over the range considered (from 17% to 8%). Pond size is the second most important parameter (from 17% to 21%). Levee width and canal bank slope influence are of lesser importance (<1% change).
Molting and Mortality of Red Swamp and White River Crawfish Subjected to Eyestalk Ablation: A Preliminary Study for Commercial Soft‐Shell Crawfish Production
Authors: Chen Shulin , Malone Ronald F. , Huner Jay V. 
Published: April 2007

AbstractEyestalk ablation may reduce the cost of soft‐shell crawfish production by reducing the molt interval. In this study, both immature and mature red swamp crawfish Procambarus clarkii and white river crawfish Procambarus zonangulus, formally Procambarus actus actus (Hobbs and Hobbs 1990), were ablated using a pair of modified pliers and placed in a recirculating system. Molting percentages, mortalities and mean molt intervals of the ablated crawfish were analyzed.Eyestalk ablation resulted in dramatic reduction of molt intervals and mortalities comparable with the current commercial (non‐ablation) soft‐shell crawfish production systems. The mean molt intervals of the ablated red swamp crawfish ranged from 6.7 to 7.8 days for immature and 9.2 days for mature animals; whereas, the molt interval of ablated white river crawfish was 8.9 and 11.2 days for immature and mature animals, respectively. Mortalities obtained in this study ranged from 20 to 48% and 32 to 66% for immature and mature crawfish, respectively. During the experiments, molting percentages and mortalities were not consistent. Secondary treatments such as air clotting and cauterization did not alter mortality significantly.
Energy Balance of Callinectes rathbunae Contreras 1930 in Floating Cages in a Tropical Coastal Lagoon
Authors: Rosas Carlos , Vanegas Cecilia , Tabares Isaac , Ramirez Judith 
Published: April 2007

AbstractThe genus Callinecres is ecologically important in the coastal lagoon region of the Gulf of Mexico. This study was conducted to test the feasibility of raising these crabs in a system of floating cages and to measure their scope for growth in a tropical coastal lagoon of the Gulf of Mexico. The equation P = As ‐ (R + E + N) was used to estimate the scope for growth (P) for C. rathbunae under experimental conditions for 21 days. Ingested food was 3% of body weight. Assimilation (As) was 73% of assimilated energy, 21.4% was channeled to respiration (R), 2% to excretion (N) and 0.16% to exuvia (E). The remainder of the energy was channeled to growth at a net efficiency of 76%. Significant differences were not found between the calculated scope for growth and the growth achieved in the culture system (P > 0.05). These results support the energy balance equation and suggest that the cultivation of C. rathbunae in floating cages is possible.
Effect of Water Exchange Rate on Production, Water Quality, Effluent Characteristics and Nitrogen Budgets of Intensive Shrimp Ponds
Authors: Hopkins J. Stephen , Hamilton Richard D. , Sandier Paul A. , Browdy Craig L. , Stokes Alvin D. 
Published: April 2007

AbstractWater exchange is routinely used in shrimp culture. However, there are few, if any, systematic investigations upon which to base exchange rates. Furthermore, environmental impacts of pond effluent threaten to hinder further development of shrimp farming in the U.S. The present study was designed to determine effects of normal (25.0%/d), reduced (2.5%/d) and no (0%/d) water exchange on water quality and production in intensive shrimp ponds stocked with Penaeus setiferus at 44 postlarvae/m2. Additional no‐exchange ponds were stocked with 22 and 66 postlarvae/m2 to explore density effects. Water exchange rates and stocking density influenced most water quality parameters measured, including dissolved oxygen, pH, ammonia, nitrite, nitrate, Kjeldahl nitrogen, soluble orthophosphate, biochemical oxygen demand, phytoplankton and salinity. Reduced‐exchange and no‐exchange treatments resulted in reduced potential for environmental impact. Mass balance of nitrogen for the system indicates that 13–46% of nitrogen input via feed is lost through nitrification and atmospheric diffusion. Growth and survival were excellent in ponds with normal exchange, reduced exchange, and a combination of low density with no water exchange. A combination of higher stocking density and no water exchange resulted in mass mortalities. Mortalities could not be attributed to a toxic effect of any one water quality parameter. Production was 6,400 kg/ha/crop with moderate stocking density (44/m2) and reduced (2.5%/d) water exchange and 3,200 kg/ha/crop with lower stocking density (22/m2) and no water exchange. Results indicate that typical water exchange rates used in intensive shrimp farms may be drastically reduced resulting in a cost savings to farms and reduced potential for environmental impact from effluent.
Acute Toxicity of Copper Sulfate and Chelated Copper to Channel Catfish Ictalurus punctatus
Authors: Straus David L. , Tucker Craig s. 
Published: April 2007

AbstractChannel catfish fingerlings Ictalurus punctatus were exposed to copper sulfate or a commercial chelated copper product in a series of static toxicity tests conducted using waters with a wide range of total alkalinity and hardness values. Estimates of mean 96 h LC50 values were 0.05, 0.73, 0.95, and 0.98 mg/L as Cu for copper sulfate and 0.06, 1.51, 1.97, and 1.74 mg/L as Cu for the chelated copper product in waters having total alkalinities of 16, 76, 127, and 240 mg/L CaCO3 respectively. On a copper basis, the chelated product was significantly (P < 0.05) less toxic to fish than copper sulfate in all waters except that of the lowest total alkalinity. Highly significant (P < 0.01) linear relationships were found between LC50 values for copper from copper sulfate and pH, log [total alkalinity], and log [total hardness], of test waters. These results cast doubt on the validity of the formula commonly used to calculate practical copper sulfate pond treatment rates, which is based upon a simple linear relationship between application rate and total alkalinity.
Larviculture of the Mahimahi Coryphaena hippurus in Hawaii, USA
Authors: Kraul Syd 
Published: April 2007

AbstractThe Mahimahi Coryphaena hippurus has excellent potential for aquaculture due to its fast growth, good food conversion ratio, high fecundity with natural captive spawns, and high price. Using current technology, three crops a year could yield 288,000 kg/ha of water/yr with a potential profit of US $1,280,000/ha water/yr.Hatchery methods are now adequate for pilot‐scale production, and two venture capital companies are pursuing this course. Significant improvement could be made in egg quality, plankton nutrition, plankton substitutes, disease control, reduced aggression, and weaning feeds. More research is needed to learn about digestive physiology, weaning behavior, and the effects of crowding on mahimahi health. Hatchery production is limited most often by the amount of grown out Artemia or yolk‐sac mahi larvae provided for postlarval feeding. Problems that occur at the broodstock, hatching, first feeding, second feeding, third feeding, weaning, and early juvenile stages are discussed.Using the current technology, the cost of post‐hatchery mahimahi is 33 cents per fry. This cost could be reduced to 6 cents per fry by successfully (consistently) weaning postlarvae from live feeds by 25 days.