bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth and Feeding Level in Pre‐Weaning Tambaqui Colossoma macropomurn Larvae
Authors: Sevilla Adrián , Günther Jorge 
Published: April 2007

AbstractThe relation between growth, feed utilization and feed ration was assessed during the first 15 feeding days in Colossoma macropomum larvae fed with Artemia nauplii. Maintenance, optimum and maximum feeding rations (1.23; 5.48 and 27.2% body weight/d, dry feed, respectively) and feed conversions (0.4 and 0.78 optimum and maximum, respectively) were determined. At maximum feeding the larvae grew 2.6 times faster that at optimum feeding, but the feeding costs increased 1.94 times. Two commonly used growth rates (specific growth rate, SGR and coefficient G) were compared for the modelling of larval growth. The maximum specific growth rate (SGR, growth rate at maximum feeding) remained relatively constant during the first 15 d of feeding and is thus much more adequate to model the growth of tambaqui larvae, than the coefficient G, which increased more than four times in this period.
Effects of Water Velocity on Growth Performance of Juvenile Japanese Flounder Paralichthys olivaceus
Authors: Ogata Hiroshi Y. , Oku Hiromi 
Published: April 2007

AbstractCritical swimming speed (Ucrit) of juvenile Japanese flounder Paralichthys olivaceus with 12.5‐cm body length was determined to be 1.8‐body lengthkec. A feeding trial was conducted to investigate the effects of water velocity on growth and other nutritional parameters of juvenile flounder (initial mean body weight: 5.7 g/fish), which is a sedentary species. The fish were raised in three water velocities, < 0.3 body length/sec (control), 0.9 body length/sec (slow) and 2.1 body length/sec (moderate), for 8 wk. Over the course of the feeding trial, the weight gain of the control, slow and moderate groups of fish were. 634%. 671% and 564%. respectively (significant between slow and moderate groups). A second order polynomial suggested that the optimum water velocity occurred at about 1.0 body length/sec. The feed efficiency of the moderate group (1.48) was significantly lower than those of the control (1.56) and slow (1.56) groups, while there were no significant differences in feed intake (1.72–1.75% of wet biomass) among the treatments. Water velocity did not affect the proximate composition of the whole body; however, rearing the fish at the moderate water velocity did slightly but significantly reduce protein retention. Lipid content of fin muscles was significantly different among the treatments: control (14.9%), slow (17.6%) and moderate groups (11.6%). Unlike salmonids, water current does not seem effective for improving growth and feed efficiency in juvenile Japanese flounder.
Fertilization and Development of Eggs of the Sea Urchin Lytechinus variegatus Maintained on an Extruded Feed
Authors: George Sophie B. , Lawrence John M. , Lawrence Addison L. , Ford John 
Published: April 2007

AbstractSea 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.
Cost Analysis for Integrating Cryopreservation into an Existing Fish Hatchery
Authors: Caffey Rex H. , Tiersch Terrence R. 
Published: April 2007

AbstractFish sperm cryopreservation is documented by a large body of technical research. However, there are no reports of the economic requirements for using this technology in aquatic species. This study establishes a generic analysis of the investment and operating costs required to integrate sperm cryopreservation into existing fish hatcheries and can serve as a template for implementation of cryopreservation programs. Equipment and supplies were identified in a species‐independent description of sperm cryopreservation, and capital and operating costs were documented for private and public hatcheries at three production capacities (3,000, 6,000, and 9,000 0.5‐mL straws). Compared to public hatcheries, investment costs were found to he 70% higher, and operating costs 20% higher for private hatcheries due primarily to interest on borrowed capital. Equipment costs were dependent on the scope of work. Investment in required equipment incurred costs of $5,460 to $10,458 (public) or $9,497 to $18,190 (private), depending on production level. Purchase of optional research equipment increased initial investment by 300% without increasing output. Per unit costs decreased at higher production levels for all scenarios, but greater economies of scale were associated with private research hatcheries. Production costs ranged between $6.13 and $1.86 per straw (private), to $1.59 to $1.18 per straw (public). Increased commercialization is expected to occur as research protocols for fish sperm cryopreservation are applied in the private sector and markets for cryopreserved sperm are established.
Effects of Dietary Lipid and Energy to Protein Ratio on Growth and Feed Utilization of Juvenile Mutton Snapper Lutjanus analis Fed Isonitrogenous Diets at Two Temperatures
Authors: Watanabe Wade O. , Ellis Simon C. , Chaves Juan 
Published: April 2007

AbstractGrowth and feed utilization of juvenile, hatchery‐reared mutton snapper Lutjanus analis (mean weight = 12.2 g) were compared for 40 d in laboratory aquaria on four isonitrogenous diets (45% crude protein) of varying lipid content (6, 9, 12 and 15%) with energy:protein ratios (E: P; kJ/g protein) of 33.9, 36.3, 38.8, and 41.2, respectively. Growth on these diets was compared under temperatures of 25 and 30 C. Final weights (Wtr) and specific growth rates (SGR) were higher (P < 0.05) at lower dietary E: P ratios of 33.9 and 36.3 (Wtr= 20.3–22.0 g; SGR = 1.25–1.35%/d) than at E:P ratios of 38.8 and 41.2 (Wtr= 17.2‐17.7 g; SGR = 0.84–0.85%/d). Growth at 30 C (Wtr= 21.5 g, SGR = 1.35%/d) was higher (P < 0.05) than at 25 C (Wtr= 17.3 g; SGR = 0.82%/d). Feed consumption (FC) was higher (P < 0.05) at a dietary E: P ratio of 33.9 (1.57%/d) than at 36.3 (1.27%/d) or 38.8–41.2 (0.89–0.98%/d). Growth was highly correlated (P < 0.01) to E: P ratio and to feed consumption. Feed conversion ratio (FCR = 2.17–3.98), protein efficiency ratio (PER = 0.58–1.03) and apparent net protein retention (ANPR = 15.8–20.0%) were not significantly (P > 0.05) affected by dietary E: P ratio. Apparent net energy retention (ANER) was higher (P < 0.05) at E: P ratios of 33.9 and 36.3 (9.50–9.98%) than at E: P ratios of 38.8 and 41.2 (7.15–7.10%). Feed utilization parameters were significantly (P < 0.05) better at 30 C (FC = 1.36%/d; FCR = 2.6; PER = 0.88; ANER = 10.2%) than at 25 C (FC = 1.03%/d; FCR = 3.38; PER = 0.69; ANER = 6.72%), with the exception of ANPR (17.0–17.8%). Maximum growth and energy retention in juvenile mutton snapper using a diet containing 45% crude protein was obtained at dietary lipid levels of 6–9% and E: P ratios of 33.9–36.3 kJ/g protein. Studies which determine optimum protein levels and the effects of reducing E: P ratios below 33.9 kJ/g are needed to improve feed conversion and growth.
Analysis of Catfish Pricing and Market Dynamics: The Role of Imported Catfish
Authors: Quagrainie Kwamena K. , Engle Carole R. 
Published: April 2007

AbstractThe producer price of catfish is becoming relatively unstable compared to the trend in previous years, necessitating the need for a complete analysis of catfish pricing and market dynamics. An understanding of the price determination mechanisms in the catfish market and the relationships between producer price, domestic processed price, and import price are important because price variability can result in significant financial losses to the domestic catfish industry. This study used a cointegration procedure to examine the long‐run relationships between domestic prices of catfish and imported price. Results from unit root and cointegration tests suggest that there is a long‐run equilibrium relationship between pairs of these prices. Results from Granger causality tests and error‐correction model estimations suggest that the market for domestic frozen fillets plays a significant role in the price determination of imported catfish. A similar relationship is found between producer price and frozen fillet price. Some significant measures that were estimated include a frozen fillet‐producer long‐run price transmission elasticity of 0.162, a frozen fillet‐imported fillet long‐run price transmission elasticity of 3.56, and a producer‐frozen fillet short‐run price transmission elasticity of 0.322. High levels of fillet prices appear to have influenced the level of catfish imports. As long as distributors and restauranteurs do not see a basis for paying a premium for U.S. catfish products, they will continue to purchase the lower‐priced imported catfish and consequently imports will continue to increase.
Economic Optimization of Shrimp Farming in Honduras
Authors: Valderrama Diego , Engle Carole R. 
Published: April 2007

AbstractA profit‐maximizing linear programming model with a risk programming component was developed to identify sets of optimal management strategies and outline an annual schedule of production activities for shrimp farming in Honduras. A database of 912 complete pond production records was used to define technical relationships between stocking density and survival and growth rates and to develop net return coefficients for the mathematical model. Separate matrices were developed for three farm‐size scenarios to account for economies of scale. Results indicated that, in spite of recent viral epizootics, shrimp farming continues to be a profitable economic activity. Stocking density was found to have a negative effect on growth rate, but not on survival rate. As a consequence, low and intermediate stocking rates were most commonly selected, but high stocking densities were recommended in certain periods of the dry season. Results demonstrated some economic advantages of reducing the traditional levels of water exchange with supplemental aeration. The risk programming analysis indicated that the selection of low and intermediate stocking rates resulted in overall annual risk levels that were relatively low.
Essentiality of Dietary n‐3 Highly Unsaturated Fatty Acids in Juvenile Japanese Flounder Paralichthys olivaceus
Authors: Kim Kyoung‐Duck , Lee Sang‐Min , Park Huem Gi , Bai Sungchul C. , Lee Yoon‐Ho 
Published: April 2007

AbstractThis study was conducted to confirm the essentiality of dietary n‐3 highly unsaturated fatty acids (n‐3 HUFA) and to investigate the effects of dietary lipid sources on growth performance, liver, and blood chemistry in juvenile Japanese flounder. Three replicate groups of fish (average weighing 3.0 g) were fed experimental diets containing lauric acid ethyl ester, soybean oil, soybean and linseed oils mixture, and squid liver oil as lipid sources for 13 wk. No significant difference was observed in survival among all groups (P >0.05). Weight gain, feed efficiency and protein efficiency ratio of fish fed the squid liver oil diet containing high n‐3 HUFA level were significantly higher than those of fish fed the other diets (P 0.05). Saturated and monounsaturated fatty acids of liver polar and neutral lipid fractions in fish fed the diet containing lauric acid tended to increase compared to those of the other groups. Fish fed the diets containing soybean and/or linseed oils, which contained high contents of 18:2n‐6 and 18:3n‐3, respectively, showed the highest contents of 18:2n‐6 and 18:3n‐3 in both lipid fractions of the liver (P 0.05). Significantly higher content of n‐3 HUFA was observed in both lipid fractions of the liver from fish fed the diet containing squid liver oil than for fish fed the other diets (P 0.05). Total cholesterol, glucose, and glutamic‐oxaloacetic acid transaminase in plasma were significantly affected by dietary lipids (P 0.05). Histologically, the liver of fish fed the diet containing squid liver oil had a clear distinction between nuclear and cytoplasm membranes; however, cytoplasm of fish fed the diets containing lauric acid and soybean oil was shrunken, and the hepatic cell outline was indistinguishable. It is concluded that the dietary n‐3 HUFA is essential for normal growth, and that the dietary lipid sources affect growth performance, liver cell property, and blood chemistry in juvenile Japanese flounder.
A Qualitative and Quantitative Approach to Determine the Optimum Combination of Feeding Stimulants for Striped Bass Morone saxatilis Using an Agar Gel Carrier
Authors: Papatryphon Elias , Soares Joseph H. 
Published: April 2007

AbstractA series of experiments was conducted to determine the optimum combination of previously identified feeding stimulants (FS), namely L‐alanine (Ala), L‐serine (Ser), inosine‐5′‐monophosphate (IMP), and betaine (Bet), for striped bass Morone saxatilis. Three experiments were conducted to determine the optimum combination of FS using an agar gel matrix as a carrier. In the first experiment a 24 factorial experiment was conducted to test all possible combinations of the four FS at two levels, 0 and 0.1 M. Significant interactions between the FS were found, suggesting the complexity of gustatory stimulation and palatability. In the second experiment a 4 × 6 factorial design was employed to test each FS alone and at concentrations ranging from 0 to 8% in order to determine the minimum level at which maximal stimulation is achieved. The results suggest that there is no significant improvement in feed intake beyond the 1 % level of supplementation for all the FS. In addition, Ala produced a significantly greater response compared to all other FS. In the last experiment, a modified single factor method was used to estimate the optimum levels for each FS in a mixture. The range of the concentrations tested was 0–1% of the agar gel for each FS. Combining all four compounds yielded maximal stimulation. The levels of each compound in the final optimum combination of FS were: Ala, 0.4; Ser, 0.6; Bet, 0.4; and IMP, 0.3% of the agar gel.
Pharmacokinetics of Dietary 13C‐Labeled Docosahexaenoic Acid and Docosapentaenoic Acid in Red Sea Bream Chrysophrys major
Authors: Tago Akio , Teshima Shin‐Ichi 
Published: April 2007

AbstractThe objectives of this study were to investigate: 1) the pharmacokinetics of dietary docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA) using 13C‐labeled fatty acids; 2) the interorgan transport of DHA in the red sea bream by monitoring the DHA level of several organs; and 3) the relationship between the plasma DHA level and optimum dietary DHA level in the plasma of the red sea bream Chrysophrys major. For this purpose, a mixture of 38.5% of [13C]DHA, 8.5% of [13C]DPA, and 4.2% of [13C]palmitic acid were given to the red sea bream at dose level of 8.0, 16.0, and 47.9 mg/kg by a single oral administration. For [13C]DHA, the maximum plasma concentration (tmax) occurred at 2.00–3.00 h after the oral administration. The peak plasma concentration (Cmax) and the area under the plasma concentration‐time curve to 24 h (AUC0‐24 for [13C]DHA level linearly increased with respect to dosage. [13C]DHA appeared in each organ (plasma, erythrocyte and the fat body of the orbit, liver, intestine, skin, brain, heart and muscle) at 0.5 h and was observed until 24 h. From the values determined for the pharmacokinetic parameters, the range of the effective plasma DHA level for normal growth of the red sea bream was suggested to be between 21.0 and 40.3 μg/mL. For [13C]DPA, the AUC0‐24 and Cmax values also linearly increased with the dosage, but tmax did not depend on it.
A Laboratory Challenge Method for Estimating Taura Syndrome Virus Resistance in Selected Lines of Pacific White Shrimp Litopenaeus vannamei
Authors: White Brenda L. , Schofield Paul J. , Poulos Bonnie T. , Lightner Donald V. 
Published: April 2007

AbstractAmong the strategies being developed to improve survival and harvest yields in the farming of Pacific white shrimp Litopenneus vannumei is breeding domesticated family lines and the selection for further development of those lines that demonstrate resistance to Taura syndrome virus (TSV) challenge in the laboratory. A standardized laboratory challenge method for measuring TSV resistance by per os exposure to the virus, relative to a reference stock of L. vannamei, was developed and used to screen a total of 176 family lines provided by five different companies over a period of several months. All challenged shrimp were exposed to TSV per os by feeding minced TSV‐positive shrimp carcasses at ∼10% of the shrimp biomass once per day for three consecutive days. Studies were carried out for a minimum of 14 d from the first day (day 0) of exposure to TSV. The survival rates obtained following TSV challenge of the selected L. vannamei families ranged from 0% to 100%, with a mean of 31%. The reference line of L. vannamei (“Kona line”) gave survival rates of 0% to 37% with a mean of 13%. The results of the present study demonstrate that the use of a relatively simple laboratory challenge procedure provides a mechanism to evaluate and compare resistance to TSV among selected L. vannamei families and to predict the performance of selected stocks in farm environments where TSV is enzootic.
Influence of Dietary Levels of Magnesium on Growth, Tissue Mineral Content, and Resistance of Channel Catfish Ictalurus punctatus Challenged with Edwardsiella ictaluri
Authors: Lim Chhorn , Klesius Phillip H. 
Published: April 2007

AbstractJuvenile channel catfish were fed purified diets supplemented with magnesium (Mg) from Mg sulfate at levels of 0, 200, 400, 600, 800, and 1,000 mg/kg and 0, 200, 400, 600, and 800 mg/kg in two separate feeding studies. In study I, the effect of dietary levels of Mg on growth response, vertebral mineral content, and macrophage chemotaxis were evaluated. Study II had similar objectives except that whole body mineral content was measured, and resistance of channel catfish to Edwardsiella ictaluri challenge was also determined. Fish with an average weight of 10.89 g were stocked at a rate of 50 fish/110‐L aquarium (study I). In study II, fish with an average weight of 4.14 g were stocked at rates of 40 fish/110‐L aquarium. Prior to stocking, each batch of fish was acclimated to laboratory conditions and fed the basal diet for 2 wk. The concentration of Mg in rearing water was 1.8 mg/L. Each diet was fed to fish in quadruplicate and triplicate aquaria to apparent satiation for 10 wk for studies I and II, respectively. Fish fed the basal diet started to die as early as 3 d after the study began (17 d of feeding the diet without Mg supplementation). In both studies, weight gain, survival, and feed efficiency were lowest for fish fed the basal diet but increased with increasing dietary levels of Mg. However, the differences between the values of each of these parameters for fish fed diets containing supplemental Mg were not always significant. Magnesium‐deficiency signs observed were anorexia, sluggishness, convulsions, deformed snout, vertebral curvature, muscle flaccidity, and high mortality. Vertebral and whole body ash concentrations were high, but Mg content was low for fish fed the basal and the 200‐mg Mg diets. Bone Ca content did not differ among fish fed different diets (study I), but whole body Ca tended to increase for fish fed the basal diet, suggesting the possibility of calcification of soft tissues. Macrophage chemotaxis in the presence of exoantigen was highest for fish fed diets supplemented with Mg at 400 and 200 mgkg for studies I and II, respectively. When expressed in terms of chemotaxis index, however, maximum or near maximum value was observed at a dietary Mg level of 400 mg/kg. Thus, a dietary level of Mg of 400 mg/kg from Mg sulfate was required for optimum growth and survival, maintaining high tissue levels of Mg, prevention of muscle flaccidity and skeletal deformity, and stimulating macrophage chemotaxis. Dietary levels of Mg had no effect on the resistance of juvenile channel catfish to Edwarsiella. ictaluri challenge.
Management Strategies for Seabream Sparus aurata Cultivation in Floating Cages in the Mediterranean Sea and Atlantic Ocean
Authors: Gasca‐Leyva Eucario , León Carmelo J. , Hernández Juan M. 
Published: April 2007

AbstractFor decades, research and development efforts have focused on fish cultivation in floating cages. Despite this focus, and the considerable private and public sector resources invested in these systems, there is a scarcity of economic data derived from the great number of variables present in these systems. A reliable way of generating economic studies is through systems modeling that relates biological, environmental, technical, and economic variables. This study presents results from a computer simulation of seabream production in floating cages under two scenarios: one representing conditions in the Mediterranean Sea, and the other in the Atlantic Ocean. A company operating in the Atlantic (Canary Islands, Spain) provided the majority of data, though some of them were provided by the University of Las Palmas, also in the Canary Islands. Given the assumptions in the simulation case study, the production cost for 1 kg of seabream in floating cages in the described systems is US$2.64 in the Mediterranean and US$2.90 in the Atlantic, and the internal rates of return were 27% and 59%, respectively. The results of model sensitivity analysis for both scenarios show that this cultivation system is more sensitive in the Mediterranean than in the Atlantic. This means that changes in system variables convey lower effects on the production and economic results in the Atlantic scenario than in the Mediterranean. In both scenarios, the feed ration size was one of the variables that improved feed conversion rates. It also improved costs and profitability in greater proportions than the other variables. The reduction of the feed ration below the levels recommended in feed tables lowered the feed conversion rate but increased the number of days in the seabream cultivation cycle, leading to higher production costs and lower internal rates of return. The analysis also showed that greater benefits and profitability could be obtained by raising production capacity through increases in the final stocking density of the system.