bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Budgets for Organically Fertilized Fish Ponds in the Dry Tropics
Authors: Green Bartholomew W. , Boyd Claude E. 
Published: April 2007

AbstractChemical budgets were determined for nitrogen, phosphorns, dissolved oxygen and chemical oxygen demand for three 0.1‐ha earthen ponds stocked withOnwchrornis nilotieusat the El Carao National Fish Culture Research Center, Comayagna, Honduras, for two 150‐d culture periods, corresponding to the rainy and dry seasons. Layer chicken litter was added to ponds weekly at 500 kg dry matter/ha. Concentrations of nitrogen (N), phosphorus (P), and chemical oxygen demand (COD) in pond water increased during each season. No significant seasonal differencea in concentrations of water quality variables were observed. Chicken litter added to ponds represented 92–94% of N input, 93–95% of P input, and 43–52% of COD input. Photosynthesis by phytoplnnkton provided 47–56% of COD and 98% of dissolved oxygen (DO) added to ponds. Net inward diffnsion of oxygen added 1.2–1.5% of total DO. Regulated inflow was a minor source of nutrients, and contributed 3–4% of input N, 3–4% of input P, 1% of COD input, and 1% of DO input. Nutrient inputs from rain were ≤1% of total for each nutrient. Fish harvest accounted for 18–21% of total N, 16–18% of total P and 2% of COD added to ponds. Community respiration accounted for 48–57% of COD and 99.5% of DO added to ponds. Nutrient losses in pond effluent at draining were: 7–9% of total N, 29–37% of total P and 2–3% of COD. While measured gains exceeded measrued losses, significpntly greater N, P and organic matter concentrations in pre‐drain samples indicated pond mud was a major sink for added nutrients, accumulation in mud represented 70% of total N, 35–40% of total P, and 38–46% of COD.
Winter Field Trials of Enrofloxacin for the Control of Aeromonas salmonicida Infection in Salmonids
Authors: Hsu H.‐M. , Bowser P. R. , Schachte J. H. , Scarlett J. M. , Babish J. G. 
Published: April 2007

AbstractThe antimicrobial enrofloxacin (Baytril®, Bayer) was evaluated under field conditions in the winter months for treatment of clinical Aeromonas salmonicida infections in salmonids by feeding medicated diets. Two trials in which lake trout Salvelinus namaycush were treated with enrofloxacin at 10mg/kg per d for 10d resulted in reduced mortalities when compared to non‐medicated controls. A third trial in which Atlantic salmon Salmo salar were treated required 20d for the fish to consume the 10d medicated ration, due to poor feeding. This resulted in an effective dose of 5mg/kg per d for 20d. In spite of the lower feeding activity, a reduction in mortalities in medicated fish was observed. Tissue concentrations of drug were in excess of minimum inhibitory concentrations of the drug for the A. salmonicida isolates tested.
Effects of Long‐Term Feeding of Cottonseed Meal on Growth, Testis Development, and Sperm Motility of Male Channel Catfish Ictalurus punctatus Broodfish1
Authors: Robinson Edwin H. , Tiersch Terrence R. 
Published: April 2007

AbstractThe effects of long‐term feeding of cottonseed meal on growth, testis development, and sperm motility of male channel catfish Ictulurus punctatus were studied. Brood‐sized male channel catfish were stocked into 0.04‐ha earthen ponds in April 1992 at the rate of 120 fish per pond. The fish were fed a diet (32% protein floating catfish feed) containing either 0, 25, 375, or 52% cottonseed meal to satiation daily, except for winter months when fish were fed on days when the water temperature was 15 C or above. Fish were harvested in July 1994. Feed consumption was similar for fish regardless of dietary treatment. Feed conversion was higher for fish fed the two highest levels of cottonseed meal and weight gain was depressed in these groups. Testis weight, gonosomatic index, and sperm motility were not negatively affected by high levels of dietary cottonseed meal indicating that reproductive capacity was not diminished. Thus it wonld appepr that up to 52% cottonseed meal could be used in the diets of brood‐sized channel catfish unless maximum gain is important. In a practical situation, growth rates of brood‐sized channel catfish are not as important as reproductive performance.
Apparent Digestion Coefficients and Metabolizable Energy of Feed Ingredients for Rainbow Trout Oncorhynchus mykiss
Authors: Smith Robert R. , Winfree Robert A. , Rumsey Gary W. , Allred Anila , Peterson Montie 
Published: April 2007

AbstractMore than 50 feedstuffs used or of potential use in diets for rainbow trout Oncorhyndus mykiss were compared through metabolism chamber trials. Testing included determination of apparent digestibility and metabolic energy for a wide variety of ingredients, including fish and animal meals, vegetable proteins, and single cell protein products. Testing involved feeding individual 200–300‐g fish contained in replicate chambers, from which feces, urine, and gill excreta were collected seg arately and analyzed for residual nitrogen and energy. For comparison, several products previously tested at this or other laboratories were re‐evaluated at dietary concentrations of 25, 50, or 100%.
Effects of Temperature on the Uptake and Depuration of 2‐Methylisoborneol (MIB) in Channel Catfish Ictalurus punctatus
Authors: Johnsen Peter B. , Lloyd Steven W. , Vinyard Bryan T. , Dionigi Christopher P. 
Published: April 2007

AbstractThe microbial metabolite 2‐methylisoborneol (MIB) imparts a muddy off‐flavor to channel catfish Ictalurus punctatus. Uptake and depuration of MIB from fish are important considerations in the design and implementation of systems to remove off‐flavors from fish prior to processing. The kinetics of MIB uptake by channel catfish were determined by placing fish in 6.5, 14.0, 25.0, and 34.0 C water containing approximately 1.0 μg/L chemically‐synthesized MIB. Fish were sacrificed following 0, 2, 4, 8, and 24 h exposure to MIB. Fillet tissue samples were subjected to gas chromatographic and fat content analysis. The model for MIB uptake was:MIB in fillet tissue (μg/kg) =−0.61 ± 4.2 [log(h± 1)] ± 0.0076(T) (h) ± 0.089(T),where h is the duration of exposure to MIB in hours and T is the water temperature in degrees C. The model accounted for 74% of the total variation observed in the tissue MIB concentrations and indicated that the fillet fat content was not strongly correlated with MIB uptake. To investigate the depuration of off‐flavors, exposure to MIB was halted. Tissue samples were obtained 4, 8, 24, 48, and 72 h from fish held at 6.5, 14.0, 25.0, and 34.0 C. These data yielded the model:MIB in fillet tissue (μg/kg) = 3.6 ± 0.176(T) – 2.06 [log(h± 1)] – 0.00296(T) (h) ± 0.197 (% fat),where h is the duration of exposure to MIB in hours, T is the water temperature in degrees C, and % fat is the % fat in the fillet tissue. The model accounted for 67% of the total observed variation in tissue MIB concentrations. Reducing the fat content of fish and optimizing water temperatures may augment MIB removal from fish tissues prior to processing.
Thyroid Hormones and Their Influences on Larval Performance and Incidence of Cannibalism in Walleye Stizostedion vitreum1
Authors: Hey Jane , Farrar Eugenia , Bristow Brian T. , Stettner Craig , Summerfelt Robert C. 
Published: April 2007

AbstractThyroid hormones, 3,5,3′,5′‐ tetraiodothyronine (T4) and 3,5,3′‐ triiodothyronine (T3) have been found in the eggs of several teleost species and are potential regulators of larval development, growth, and survival. The purpose of the present study was to determine whether natural variation of T3 and T4 in the eggs of six stocks of walleye, five wild stocks from Kansas, Iowa, Wisconsin, Minnesota, and North Dakota, and a semi‐domesticated stock from an Ohio fish hatchery, have an effect on larval performance in mass culture. Immersion studies were conducted with samples of larvae from four of the same stocks at exposure concentrations of 0.01, 0.05, and 0.1 ppm of T3 and T4. Natural egg concentrations of T3 (range from 0.70 to 1.5 ng/g wet weight of egg) were not significantly different among stocks. Although means of T4 concentration among stocks were significantly different (range 0.53–9.27 ng/g), the difference was caused by the exceptionally high concentration for the Wisconsin stock (9.27 ng/g ± 2.20). Performance measures of the Wisconsin stock (Mississippi River), were not related to T4 concentration in that stock. In spite of similarity in concentrations of T4 and T3 in the eggs, there were significant performance differences among the stocks (survival to 21 d, gas bladder inflation, viability, cannibalism, and growth). The immersion studies, however, revealed a significant difference in incidence of cannibalism and temperature units (TU) to 50% mortality (i.e., survival) between the control groups and treatment groups exposed to 0.01 to 0.1 ppm T3 and T4. Survival was extended more than 2‐fold longer in larvae immersed in T3 compared with T4. The immersion study indicated that thyroid hormones are potentially regulators of walleye development, but further investigations are needed to determine reasons for differences in larval performance based on natural concentrations in the egg and artificial exposure (immersion).
Effects of Dietary Energy: Protein Ratio and Stocking Density on Growth and Survival of the Common Snapping Turtle Chelydra serpentinal1
Authors: Mayeaux Maxwell H. , Culley Dudley D. , Reigh Robert C. 
Published: April 2007

AbstractAlthough the common snapping turtle Chelydra serpentina is cultured commercially in the United States, little information is available on nutritional and culture requirements. This study was conducted to evaluate the effects of dietary energy: protein ratio and stocking density on survival, growth, feed consumption, feed conversion, liposomatic index, dress‐out percentage, and productive protein value of cultured, common snapping turtles. Hatchling turtles were stocked at 29 and 58 animals/m2 and fed one of seven prepared diets. Six diets contained 30, 35, or 40% protein at two digestible energy (DE) levels (7 or 9 kcal DE/g protein); the seventh was a reference diet (66% protein and 5 kcal DE/g protein) formulated to equal or exceed the whole‐body essential amino acid composition of wild, common snapping turtles. Turtles stocked at 58/m2 exhibited greater mortality, lower weight gain, higher feed consumption, less‐efficient feed conversion, lower liposomatic index, and lower productive protein value than turtles stocked at 29/m2 (P < 0.05). The reference diet produced the greatest weight gain (P < 0.001). The superior performance of turtles fed the reference diet suggests that: 1) the protein (amino acid) content and/or energy: protein ratio of the reference diet was superior to that of the other diets tested; 2) improvements in growth parameters can be made with dietary manipulation; and 3) high levels of plant protein can be used in prepared, snapping turtle diets.
Neurotoxin Production by a Chloromonad Fibrocapsa japonica (Raphidophyceae)
Authors: Khan Saleha , Arakawa Osamu , Onoue Yoshio 
Published: April 2007

AbstractThe ichthyotoxicity and toxin composition of a red‐tide producing chloromonad Fibrocapsa japonica (Toriumi and Takano) were examined. The flagellate showed the highest toxicity in mid‐logarithmic phase and the lowest in the stationary phase with increased number of spherical‐shaped cells. Five neurotoxic components, FjTx‐I, FjTx‐II, FjTx‐IIIa, FjTx‐IIIb and FjTx‐IV, which corresponded to brevetoxin components, PbTx‐1, PbTx‐2, PbTx‐9, PbTx‐3 and oxidized PbTx‐2 were tentatively identified from analysis of F. japonica toxins on TLC and HPLC. The quantity of each component fluctuated with the age and growth stage of the culture. Among the five toxic components the yield of FjTx‐II per cell was highest in both logarithmic and stationary phases.
The Effects of Fry Rearing Density on Hatchery Performance, Fin Condition, and Agonistic Behavior of Rainbow Trout Oncorhynchus mykiss Fry
Authors: Wagner Eric J. , Intelmann Steven S. , Routledge M. Douglas 
Published: April 2007

AbstractRainbow trout Oncorhynchus mykiss fry were reared at four densities ranging from 10,800 to 43,926 fish/m3 (9.91 to 37.60 kg/m3) during an initial feeding period of 35 d. Each of the four initial density treatments were then split into high (3,780 fish/m3) and low (1,890 fish/m3) density groups and reared in outdoor raceways for an additional 74 d. A necropsy‐based general health and condition assessment indicated that hematocrit, plasma protein, and the thymus index were significantly elevated in the outdoor high density group. Changes in these variables were unrelated to the initial rearing density, except for plasma protein which decreased as the initial density increased at low densities. Other necropsy variables indicated normal, healthy fish. Agonistic behavior was assessed at 4, 9 and 13 wk of age by observing the number of aggressive chases in paired and group (five fish) trials. The number of chases generally increased with age, although the difference between 9 and 13 wk was variable. Feeding did not elicit more chases in this study except for 9‐wk‐old fry. Initial rearing density did not have any impact on the number of chases at 4 or 13 wk, but at 9 wk the number of chases increased with initial density for the group tests. Relative fin length measurements of all fins except the adipose indicated no combination of initial density and outdoor density was superior to another for reducing fin erosion. This study indicated that rainbow trout fry may be reared at initial densities approaching 44,000 fish/m3 (Piper density index of 1.1) without negatively affecting growth and fin condition or inducing higher levels of agonistic behavior later on.
Use of Microbial Phytase in Channel Catfish Ictalurus punctatus Diets to Improve Utilization of Phytate Phosphorus1
Authors: Jackson L. Scott , Li Meng H. , Robinson Edwin H. 
Published: April 2007

AbstractA 10‐wk feeding trial was conducted in the laboratory during which channel catfish Ictalurus punctatus (average initial weight: 6.5 g/fish) were fed five practical diets containing either 0, 500, 1,000, 2,000, or 4,000 units of microbial phytase/kg diet. Fish fed diets containing 500 or more units of microbial phytase/kg consumed more feed and gained more weight than fish fed the basal diet without supplemental phytase. Feed conversion ratios (FCR) did not differ among treatments except the FCR for fish fed 1,000 units of microbial phytase/kg diet was lower than that of fish fed no supplemental phytase. Fish survival was not different among treatments. Contrast analysis showed that weight gain, feed consumption, bone ash, and bone phosphorus were higher and feed conversion ratio was lower for fish fed diets supplemented with phytase as compared to fish fed no supplemental phytase. The concentration of fecal phosphorus decreased linearly as phytase supplementation increased. Results from this study demonstrate that microbial phytase is effective in improving bioavailability of phytate phosphorus to channel catfish, which may eventually lead to a reduction in the amount of supplemental phosphorus added to commercial channel catfish feeds.
Induced Final Maturation and Spawning of the Marbled Grouper Epinephelus microdon Captured from Spawning Aggregations in the Republic of Palau, Micronesia
Authors: Tamaru Clyde S. , Carlstrom‐Trick Christine , Fitzgerald William J. , Ako Harry 
Published: April 2007

AbstractA high percentage (98.3%, N= 60) of the marbled grouper Epinephelus microdon individuals captured from spawning aggregations during July and August 1993 in the waters surrounding the island of Koror, Republic of Palau, Micronesia, were in the stage of maturity at which final maturation and spawning could be hormonally induced. The sex ratio of the captured fish was highly skewed towards males (4 male:1 female). Sexually immature females comprised the smallest size class, (<0.6 kg body weight (BW) or 33.0 cm total length (TL)), while sexually mature females were restricted to the 0.6–1.5 kg BW (33.0–46.4 cm TL) groups. Males predominated in size classes >0.6 kg BW, and individuals >1.5 kg BW (46.4 cm TL) were exclusively male. All females with oocytes that averaged (N= 50) >400 μm in diameter were successfully induced to spawn by a two‐injection protocol using human chorionic gonadotropin (HCG) at total dosages of 2,100–3,200 IU/kg fish. All males used in the spawning trials were administered a single injection of HCG at dosages of 500 or 1,000 IU/kg fish. Fecundity ranged between 7.96 × 105−1.24 × 106kg BW, average spawned egg diameters ranged between 769–832 μm, percent fertilization ranged between 32.6%–99.9%, and hatching percentages were >90.0%. Total fat content of eggs obtained from a pooled spawning event was 14.1 mg/100 mg dry weight. The data indicate that HCG is a suitable treatment for the induction of spawning in marbled grouper females that possess a mean oocyte diameter of 400 μm or greater.
Voluntary Spawning of Captive Nassau Groupers Epinephelus striatus in a Concrete Raceway
Authors: Tucker John W. , Woodward Peter N. , Sennett Daniel G. 
Published: April 2007

AbstractNassau groupers Epinephelus striatus held in a 37‐m3 concrete raceway were conditioned to spawn 3 mo later than in their home waters. After being held in the raceway for 15 mo, four female and two male groupers spawned voluntarily over a 4‐d period in March 1994, producing 10.3 million eggs. By December 1994, two females had been removed. During March 1995, one of the remaining two females spawned on three consecutive days (60 cm TL, 1,172,000 eggs) and the other only on the third day (47 cm TL, 488,000 eggs). In April 1995, three females (including one held in isolation for 6 mo, then replaced 6 d before the first spawn) produced more than 9.8 million eggs in 4 d. The isolated female spawned 8 d after being placed in a cage in the raceway and 4 d after release in the raceway.Individual females spawned as many as nine times a day for 1–4 d. Spawning occurred from 3.5 d before until 8.5 d after the full moon. A 30‐d interval elapsed between March and April 1995 spawning periods. Fertilization was in the range 83–100% and hatching 90–100%. Spawns occurred in a temperature range of 23.1–27.9 C; however, based on spawning frequency and volume and on egg development, 24–27 C seems most suitable. These results and other evidence support the view that Nassau groupers can be conditioned to spawn any month of the year, mainly by manipulating temperature.
Sludge Production and Management for Recirculating Aquacultural Systems
Authors: Chen Shulin , Coffin David E. , Malone Ronald F. 
Published: April 2007

AbstractWaste discharge from recirculating aquacultural systems is typically in the form of sludge composed of partially stabilized excreta, uneaten food particles, and bacterial growth. The amount of solids produced can be estimated using an equation presented in this paper. In a typical recirculating system, total suspended solids (TSS) is the major pollutant of the sludge produced. The production of TSS ranges from 10 to 30% of the feeding rate on a dry weight basis. The ratio of 5‐d biochemical oxygen demand to total suspended solids (BODS/TSS) of the sludge ranges from 0.10 to 0.2, the total Kjeldahl nitrogen (TKN) content of the TSS ranges from 4 to 6%, and total phosphorus ranges from 0.2 to 2%.The nature of the waste and the economics of the treatment processes dictate the disposal of aquacultural sludge. Effective clarification of aquacultural waste is critical in reducing sludge volume. Using lagoons for stabilization and storage is the most practical option. While direct disposal by land application seems feasible for rural areas with dry climates, additional stabilization/storage in a lagoon with eventual disposal through land application seems most feasible for a variety of conditions. The effluent produced from the sludge treatment processes can be used for irrigation or for direct discharge after further polishing (treatment).
Diet and Light Intensity Effects on Survival, Growth and Pigmentation of Southern Flounder Paralichthys lethostigma
Authors: Denson Michael R. , Smith Theodore I. J. 
Published: April 2007

AbstractInterest in the culture of flatfishes has increased globally due to high consumer demand and decreased commercial landings. The Southern flounder Paralichthys lethostigma inhabit South Atlantic and Gulf of Mexico waters and support important commercial and recreational fisheries. In spring, 1996, a two‐part larval rearing study was performed with Southern flounder to examine the effects of three larval diets and two light intensities on survival, growth, and pigmentation. The first part of the study consisted of feeding 6 d post‐hatch (dph) (3.0 ± 0.1 mm TL) larvae three diets: 1) rotifers Brachionus plicatilis at a rate of 10/mL from day 1–9 and Artemia nauplii (3/mL) from day 7 through metamorphosis; 2) rotifers fed day 1 through metamorphosis and Artemia fed day 7 through metamorphosis; or 3) same diet as treatment 1 plus a commercial larval diet added day 13 through metamorphosis. The second part of the study examined the effects of two light levels: low‐light (mean 457 lux) and high‐light (mean 1362 lux). At 24 C, metamorphosis began on day 23 (mean fish size 8.2 ± 0.6 mm TL) in all treatments and was completed by day 30. Analysis of survival, size, and pigmentation data indicated there were no significant differences among feed treatments or between light treatments. Overall survival was 33.4% (±15.9) and mean length was 11.5 mm TL ± 1.3. Only 35% of the larvae were normally pigmented. Reexamination of the pigmentation on day 37 indicated fish reared at the low light intensity through metamorphosis (day 30) but exposed to high light intensity for 1 wk post‐metamorphosis had become significantly more pigmented.
Effects of Replacing Fish Meal with Soybean Meal in Diets for Red Drum Sciaenops ocellatus and Potential for Palatability Enhancement
Authors: McGoogan B. B. , Gatlin D. M. 
Published: April 2007

AbstractTwo 8‐wk feeding trials were conducted with juvenile red drum to determine the maximum levels of soybean meal that may replace fish meal in diets containing 38% crude protein, without reducing weight gain. In the first experiment, fish fed diets containing up to 90% of the protein from soybean meal gained as much weight as fish fed a diet with 100% of protein from fish meal, but fish fed the diet with 100% of its protein from soybean meal gained significantly (P < 0.05) less. Supplementation of glycine and fish solubles individually at 2% (as‐fed basis) in diets containing 90% of their protein from soybean meal tended to increase weight gain of fish compared to those fed a similar diet without supplementation. Similar results were obtained in the second experiment, as fish fed diets containing 90% of their protein from soybean meal gained as much weight as fish fed a diet with 100% of its protein from fish meal. Fish fed diets with 95% and 100% of their protein from soybean meal gained significantly less weight than those fed the diet with all of its protein from fish meal. Supplementation of glycine at 2% in the diet containing 95% of its protein from soybean meal significantly improved weight gain of fish relative to those fed a similar unsupplemented diet. Supplementation of fish solubles at 5% of diet on a dry‐matter basis provided a nonsignificant increase in weight gain compared to that of fish fed a similar unsupplemented diet. In both experiments there was greater observed consumption of the soybean‐meal‐based diets than diets with all of their protein from fish meal. A minimum of 10% of protein from fish meal appears necessary in practical diets containing most of their protein from soybean meal to prevent impaired growth and feed efficiency of red drum.