bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Prevention and Treatment of Winter Saprolegniosis (“Winter Kill”) in Channel Catfish Ictalurus puncfatus1
Authors: Li Meng H. , Wise David J. , Robinson Edwin H. 
Published: April 2007

AbstractThe efficacies of formalin, potassium permanganate, sodium chloride, and copper sulfate as prophylactic treatments for saprolegniosis (“winter kill”) in channel caffish Icralums puncratus were evaluated. Formalin and copper sulfate were also evaluated as postinfective treatments for the disease. Each of the five experiments was conducted with 5–to 7‐g channel catfish placed in static water aquaria maintained in refrigerated tanks. Water temperature was reduced from 25 to 10 C within 36 h and maintained at 10 ± 0.5 C for 28 d. Fish were exposed to cultured Saprolegnia sp. at 20 C, and morbidity and mortality data were recorded for 28 d. Saprolegnia sp.‐associated mortalities occurred 7–10 d after exposure. Formalin (25 mg/L) was effective as both a prophylactic and postinfective treatment for saprolegniosis. Copper sulfate was effective in preventing saprolegniosis at a concentration of 0.1 mg/L, but was ineffective as a postinfective treatment. Sodium chloride at 5,000 mg/L was effective in preventing saprolegniosis, but was not practical for use in the commercial catfish industry. Potassium permanganate (up to 0.5 mg/L) was not effective in preventing or treating saprolegniosis in channel caffish. Based on the results of this study, it may be possible to prevent saprolegniosis in channel catfish using formalin or copper sulfate during winter when fish are immunosuppressed by rapid decreases in water temperature or to treat infected fish with formalin. However, the routine use of chemicals to control this disease should not be recommended until studies on their efficacy under typical caffish culture conditions and the effect of long‐term use of chemicals on fish and on the environment are completed.
Evidence for Control of Water Quality in Channel Catfish Ictalurus punctatus Ponds by Phytoplankton Biomass and Sediment Oxygenation
Authors: Hargreaves John A. , Tucker Craig S. 
Published: April 2007

AbstractA data set describing annual variation of water quality in ten commercial channel catfish Ictalurus punctatus ponds was subjected to exploratory statistical analysis to infer ecological processes affecting pond water quality. Two factors explained 67% of the variation in concentrations of water quality variables. The first factor (Factor 1) explained 49% of the variance and was associated with a large negative loading by total ammonia‐nitrogen and large positive loadings by total nitrogen, total phosphorus, chemical oxygen demand, and chlorophyll a. Factor 1 was interpreted with respect to factor loadings to represent the effect of phytoplankton biomass. The second factor (Factor 2) explained an additional 18% of the variance and was associated with a large negative loading by soluble reactive phosphorus and large positive loadings by nitrite‐nitrogen and, to a lesser extent, nitrate‐nitrogen. Factor 2 was interpreted to be related to variation in pond sediment oxygenation. Although factor analysis indicated the overwhelming effect of phytoplankton biomass on water quality, opportunities for management of phytoplankton communities in large commercial aqua‐culture ponds are limited. However, maintenance of an oxidized sediment‐water interface may improve water quality by limiting the diffusion of reductant‐soluble phosphorus from sediment to water and increasing sediment nitrification rates.
Effect of Dietary Protein Level on Apparent Heat Increment and Post‐Prandial Nitrogen Excretion of Penaeus setiferus, P. schmitti, P. duorarum, and P. notialis Postlarvae
Authors: Rosas Carlos , Sanchez Adolfo , Diaz Eugenio , Soto Luis A. , Gaxiola Gabriela , Brito Roberto 
Published: April 2007

AbstractThe calorigenic effect of feeding (apparent heat increment, AHI) and post‐prandial nitrogen excretion (PPNE) were measured in postlarval (PL 25–30) Penaeus setiferus, P. schmitti, P. duorarum and P. notialis fed a fixed ration of 3 mg/animal using purified diets with 40, 50, 60, or 65% protein. Both AHI and PPNE increased with increasing dietary protein. The contribution of PPNE to AHI varied from 6.1 to 94%, with lesser values for P. setiferus and greater ones for P. duorarum. Also, the AHI coefficient (percentage of ingested energy) increased with increasing dietary protein. The AHI and PPNE coefficients for the four shrimp species ranged from 0.3 to 6.5% and 0.02 to 5.04% of ingested energy, respectively. These results suggest close relationships among protein requirements, the capacity to use dietary proteins as a source of energy, and adaptation by different species to different types of food. The amount of energy used for production of ammonia is proposed as an adequate measure of the part played by dietary proteins in food cost.
Economic Evaluation of Commercial‐Scale, Saltwater Pond Production of Florida Red Tilapia in Puerto Rico
Authors: Head William D. , Zerbi Alfonso , Watanabe Wade O. 
Published: April 2007

AbstractAn economic analysis was performed of a proposed commercial‐scale 20‐ha saltwater pond culture operation for Florida red tilapia in Dorado, northern Puerto Rico. The analysis was based on actual cost and production data from a commercial‐scale hatchery, pilot‐scale grow‐out trials conducted in six 0.2‐ha saltwater (avg. = 22.7 ppt) ponds at the Dorado facility and on wholesale market prices ($4.96–5.18/kg) fetched by dressed‐out (gilled, gutted and scaled) product. The proposed 20‐ha growout facility is comprised of 25 0.8‐ha earthen ponds, each supplied with sea water, brackish well water, drainage and aeration, which account for 60.8% of the capital costs. Ponds are stocked with fingerlings (0.85 g avg. wt.) at a density of 3.0 fish/m2 (30,000/ha), and are harvested at 160 and 220 d, at an average weight of 545 g for a total yield of 11,445 kg/ha per crop. Imported feed ($0.55/kg), processing and distribution ($0.50/kg) and sex‐reversed fry ($0.11/fry) are the highest variable costs, accounting for 30.7%, 15.4% and 13.9%, respectively, of the total annual costs. Salaries and benefits, and depreciation represent the highest fixed costs, accounting for 8.4% and 5.5%, respectively, of the total annual costs. Under these conditions, a wholesale price of $4.55/kg results in a positive cash flow by year eight, and a breakeven price, internal rate of return (IRR), net present value (NPV) and discounted payback period (DPP) of $4.08/kg, 7.6%, ($235,717) and >10 yr, respectively, suggesting that the proposed 20‐ha operation is not economically feasible under these conditions. The proposed enterprise is marginally feasible if stocking density is increased to 3.5 fish/m2 while at 4.0 fish/m2 economic outlook is favorable. Costs can be lowered considerably by targeting production and market variables most sensitive to profitability indices, using locally‐prepared feeds, and vertically integrating hatchery and growout operations.
Phosphorus Availability of Common Feedstuffs to Channel Catfish Ictalurus punctatus as Measured by Weight Gain and Bone Mineralization1
Authors: Li Meng H. , Robinson Edwin H. 
Published: April 2007

AbstractThe efficacy of using weight gain and bone mineralization to estimate phosphorus availability from feed ingredients for channel catfish was investigated at the conclusion of a 12‐wk feeding trial. Juvenile channel catfish (initial weight = 7.8 g/fish) were fed one of seven test diets each containing phosphorus from a single source. All diets were isocaloric, isonitrogenous, and met all nutrient requirements of channel catfish except for phosphorus, which was assumed to be the factor limiting growth. Phosphorus was considered to be 90% available to fish fed the diet containing monosodium phosphate, but a relative value of 100 was assigned to this treatment for purposes of comparison. All other availability values were calculated relative to this value. Phosphorus availabilities (based on weight gain) for wheat middlings, cottonseed meal, and soybean meal were 38%, 43%, and 49%, respectively, which are in the range previously reported for channel catfish. Phosphorus availability values (based on weight gain) for dicalcium phosphate, menhaden fish meal, and meat and bone/blood meal were 82%, 75%, and 84%, respectively. These values were considerably higher (93–96%) than previously reported for catfish when based on bone ash or bone phosphorus. However, availability data based on weight gain for feedstuffs of animal origin generally agreed with phosphorus availability data reported for rainbow trout. Based on our data, mineral utilization by animals in general, and on known physiology of channel catfish, we suggest that weight gain may be a reliable indicator of phosphorus availability and that phosphorus availability values may be overestimated when base on bone mineralization.
Evaluation of First‐Feeding Regimens for Larval Nassau Grouper Epinephelus straitus and Preliminary, Pilot‐Scale Culture through Metamorphosis
Authors: Watanabe Wade O. , Ellis Simon C. , Ellis Eileen P. , Lopez Vicente Gracia , Bass Paul , Ginoza John , Moriwake Aaron 
Published: April 2007

AbstractTwo 10‐day hatchery experiments were conducted to evaluate s‐type (Hawaiian strain) and ss‐type (Thailand strain) rotifers Brachionus plicatilis and cryogenically preserved oyster Crassostrea gigas trochophores as first feeds for larval Nassau grouper Epinephelus striatus. Newly hatched grouper larvae were reared at densities of 11.2–20.8/L in 500‐L tanks at 36–38 ppt salinity, 25–26 C, and under a 11‐h light: 13‐h dark photoperiod. Beginning on day 2 posthatching (d2ph), prey were maintained at a density of 20 individuals/mL, while phytoplankton (Nanochloropsis oculata) was maintained at 500 × 103 cells/mL. In experiment 1, survival and growth were higher (P < 0.05) for fish fed small s‐type rotifers (mean lorica length = 117 μm; fish survival = 7.96%) selected by sieving than for fish fed non‐selected rotifers (mean lorica length = 161 μm; fish survival = 2.13%). These results demonstrated the advantage of small prey size and suggested that super‐small (ss‐type) rotifer strains would be beneficial. In experiment 2, three feeding regimens were compared: 1) ss‐type rotifers (mean lorica length = 147 μm); 2) oyster trochophores (mean diameter = 50 μm) gradually replaced by ss‐type rotifers from d5ph; and 3) a mixed‐prey teatment of 50% oyster trochophores and 50% ss‐type rotifers. Survival was higher (P < 0.05) for larvae fed mixed prey (15.6%) than for those fed rotifers (9.73%) or trochophores and rotifers in sequence (2.55%), which also showed the slowest growth. Oyster trochophores, although inadequate when used exclusively, enhanced survival when used in combination with rotifers, possibly by improving size selectivity and dietary quality. In a pilot‐scale trial, larvae were cultured through metamorphosis in two 33.8‐m3 outdoor tanks. Fertilized eggs were stocked at a density of 10 eggs/L and larvae were fed ss‐type rotifers from d2ph‐d20ph, newly hatched Artemia from d15ph‐d18ph, 1‐d‐old Artemia nauplii from d18ph‐d62ph. Survival on d62ph was 1.17%, with a total of 5,651 post‐metamorphic juveniles produced.
Initial Disease Report of Streptococcus iniae Infection in Hybrid Striped (Sunshine) Bass and Successful Therapeutic Intervention with the Fluoroquinolone Antibacterial Enrofloxacin
Authors: Stoffregen D. A. , Backman S. C. , Perham R. E. , Bowser P. R. , Babish J. G. 
Published: April 2007

AbstractStreptococcal infection (Streptococcus iniae) was diagnosed sequentially in two tanks of hybrid striped bass Morone saxatilis male ×M. chrysops female (Sunshine bass) grown in a commercial freshwater recirculation facility in western Massachusetts. The pathogen was isolated in the laboratory, biochemically and morphologically characterized, and antibacterial sensitivities determined. Streptococcus iniae‐induced lesions in the Sunshine bass were character at the gross and histopathological levels. Initial treatment with oxytetracycline was unsuccessful. Based on sensitivity results, enrofloxacin‐medicated feed was dosed at 10 mg/kg body weight for 10 d, while a subsequent trial was conducted at 5 mg/kg body weight for 10 d. Mortality of fish subsided promptly following initiation of enrofloxacin therapy, yielding a final mortality in the initial tank of 10.83% (control tank 55.5%) and in the second tank of 16.97% (control tank 39.8%). Tissue enrofloxacin residues, detected via a microbiologic bioassay, revealed greater quantities and longer duration of residues in various tissues from the 5‐mg as compared to the 10‐mg trial, potentially the result of adverse feed palatability. Enrofloxacin appears to have excellent potential as an antibacterial agent for treating susceptible bacterial diseases of Sunshine bass.
Comparisons of Uptake and Depuration of 2‐Methylisoborneol in Male, Female, Juvenile, and 3MC‐induced Channel Catfish Ictalurus punctatus
Authors: Perkins Everett J. , Schlenk Daniel 
Published: April 2007

AbstractThe occurrence of off‐flavors in farm‐raised channel catfish is a major burden to the catfish culture industry, causing millions of dollars worth of market‐ready fish to be rejected each year. Off‐flavors are believed to be the result of exposure and subsequent accumulation of certain volatile microbial metabolites such as 2‐methylisoborneol. In this study, the uptake and elimination of [14C]‐2‐methylisoborneol equivalents were examined in juvenile and mature channel catfish. The described method is presented as a simple and inexpensive procedure for comparing treatment effects on off‐flavor elimination rates. In addition, the effects of the cytochrome P4501A inducing agent 3‐methylcholanthrene on 2‐methylisoborneol depuration was studied in juvenile fish. Uptake was determined during a 24–h static exposure to waterborne 2‐methylisoborneol (7.6 ± 3.7 μg/L). Uptake equilibrium had been established in all groups by 12 h, with total uptake higher in juvenile fish. Depuration rates were not different between untreated groups (t½ a = 12.r122.4 h; t½β= 91.3–143.7 h); however, the depuration half‐lives for 3‐methylcholanthrene treated juveniles were significantly longer than those of controls.
Improved Utilization of Pond Carrying Capacity by Increasing Initial Stocking Rates and Subsequent Stock Division1
Authors: Terhune Jeffery S. , Schwedler Thomas E. , Collier John A. 
Published: April 2007

AbstractFingerling channel catfish Ictaturus punctarus were stocked into eight 0.04‐ha ponds at 12,500 fishlha (treatment 1) and 50,000 fish/ha (treatment 2) with four ponds per treatment. At the end of of phase I (59 d) 50% of the fish were removed from each of the ponds in treatment 2 and divided equally into two ponds, forming treatment 3 (eight ponds at a density of 12,500 fish/ha). The remaining fish in treatment 2 (25,000 fish/ha) were maintained in the original ponds until the end of phase II (36 d). At this time, the fish were removed and equally divided at a density of 12,500 fish/ha into separate ponds. These ponds were continued to be denoted as treatment 2. All fish were grown for a total of 188 d. Production characteristics between treatments were compared at phases and at the end of the 188 d. There was no significant difference in feed conversion ratios due to treatment. The individual weights of the fish were higher in treatment I, but the difference occurred only in phase I. Size variabilities in treatments 2 and 3 were also higher than in treatment 1, which may cause a decrease in the percentage of marketable fish. Although there were some adverse effects due to the initial high stocking densities, overall pond production was higher in treatments 2 and 3. Treatment 2 had a daily net production of 49.9 ± 3.43 kg/ha and treatment 3 had 44.6 ± 3.81 kg/ha per d, compared to treatment 1 with only 32.4 ± 1.06 kg/ha per d (mean ± SD).
Hormone Induced Spawning of Summer Flounder Paralichthys dentatus
Authors: Berlinsky David L. , William King V , Hodson Ronald G. , Sullivan Craig V. 
Published: April 2007

AbstractDuring their first year in captivity, summer flounder Paralicthys denratus were induced to spawn with gonadotropin releasing hormone analogue (GnRHa) implants, injected carp pituitary extract (CPE) or human chorionic gonadotropin (hCG) injections. The percentage of fertile eggs was greatest (69%) in CPE‐treated females. CPE, but not GnRHa or hCG, was capable of stimulating oocyte growth (increased follicle diameter during vitellogenesis) followed by ovulation. Fish with maximum ovarian follicle diameters between 180 and 435 μm at the initiation of CPE injections produced the greatest percentage of fertile eggs. For most females, fertilization rate was greatest for the first batch of eggs ovulated. The mean fertilization rate for the first spawn of CPE‐treated fish was 42% compared with 14% for the second spawn from the same fish. Fish with maximum initial follicle diameters of 585 40 μm that were implanted with GnRHa ovulated the greatest number of eggs, but fertility was low and variable. Approximately 35% of females injected with hCG ovulated a limited number of eggs, but only one hCG‐treated female produced fertile eggs. Only a limited number of spermiating males were available for spawning trials. Hormone treatments used on females were ineffective for inducing or maintaining spermiation in male summer flounder.
Tolerance of Snakehead Channa striatus to Ammonia at Different pH
Authors: Qin Jianguang , Fast Arlo W. , Kai Ashley T. 
Published: April 2007

AbstractTolerance of snakehead Channa striatus to ammonia was tested at three pH levels (8.0, 9.0. and 10.0) in experimental tanks. At pH 8.0, ammonia LC50 estimates for snakehead at 24, 48, 72, and 96 h were >205.7, >203.5, 152.6, and 107.3 mg total ammonianitrogen (TAN)/L (or >10.3, >10.2, 7.6, and 5.4 mg NH3‐N/L), respectively. At pH 9.0, ammonia LC50 estimates at 24, 48, 72, and 96 h were >52.4, 62.8, 56.1, 43.4 mg TAN/L (or >18.0, 21.6, 19.3, and 14.9 mg NH3‐N/L), respectively. At pH 10.0, ammonia LC50 estimates at 24, 48, 72, and 96 h were 25.7, 21.6, 20.3, and 18.7 mg TAN/L (or 21.6, 18.1, 17.1, and 15.7 mg NH3‐N/L). respectively. Our data indicate that the tolerance of snakehead to ammonia was associated with pH. Thus, we recommend that snakehead should not be subjected to prolonged exposures of NH3‐N concentration more than 0.54 ma at pH 8.0, more than 1.49 mg/L at pH 9.0, or more than 1.57 mg/L at pH 10.0.
Effect of Acclimation Temperature and TemperatureChanges on Molting and Survival of Ablated and Non‐ablated Crayfish Orconectes virihs
Authors: Twibell Ronald G. , Wilson Keith A. , Brown Paul B. 
Published: April 2007

Abstract.The effect of acclimation temperatures for producing soft‐shell crayfish, and changes upward from acclimation temperature, were evaluated in crayfish Orconectes virilis subjected to either hemilateral or bilateral eyestalk ablation. In each experiment, 60 juvenile O. virilis were reared for 21 d at temperatures ranging from 20 C to 30 C. Equal numbers of male and female crayfish ranging in weight from 5.0 g to 16.0 g were used in each study. In the first three experiments, crayfish were acclimated and maintained at a constant temperature. In the remaining experiments, crayfish were subjected to a step‐wise increase in temperature of either 5 or 10 C. Molting was highest in crayfish acclimated to 25 C prior to experimentation at 25 C (experiment 2) and in crayfish acclimated to 14 C prior to experimentation at 20 C (experiment 4). Total molts during these two experiments were 51 (85.0%) and 56 (93.3%), respectively. Bilateral eyestalk ablation resulted in significant reductions in the intermolt period in experiments 1 (acclimation temperature 20 C, experimental temperature 20 C), 3 (acclimation temperature 30 C, experimental temperature 30 C) and 6 (acclimation temperature 15 C, experimental temperature 25 C), while hemilateral eyestalk ablation had no effect on molting when compared to control (non‐ablated) crayfish. Bilateral eyestalk ablation resulted in a significant reduction in survival in experiments 5 (acclimation temperature 20 C, experimental temperature 25 C) and 6 (acclimation temperature 15 C, experimental temperature 25 C). Significantly more females molted in one experiment (acclimation temperature 20 C, experimental temperature 25 C), but not in any others. The results of these studies demonstrate that bilateral eyestalk ablation and water temperatures are effective methods of inducing molting in crayfish.
Water Quality and Phytoplankton Communities in Intensive Shrimp Culture Ponds in Kung Krabaen Bay, Eastern Thailand
Authors: And Siri Tookwinas , Songsangjinda Putth 
Published: April 2007

Abstract.Water quality and phytoplankton communities were studied in 20 intensive shrimp culture ponds and in the inlet and drainage canals at Kung Krabaen Bay, Eastern Thailand during the first shrimp crop of 1992. The grow‐out ponds were categorized into two groups: low stocking density (<60 PL/m2) and high stocking density (>60 PL/m2). The results showed that there were no significant differences in water quality between the two stocking density groups. Phytoplankton collected using a 60‐μm mesh net consisted of 79 genera with concentrations ranging from 1,822 to 72,527 cells/L from the first month up to the time of shrimp harvesting. Water quality deteriorated in high and low stocking density shrimp ponds, which had an influence on abundance and diversity of net phytoplankton communities. Biochemical oxygen demand and ammonia‐nitrogen were most closely related to abundance of net phytoplankton communities during the shrimp grow‐out period. Salinity, temperature, and dissolved oxygen appeared to play an important role in phytoplankton community variation in inlet and drainage canals. Phytoplankton community structure in drainage canals showed more variation than in ponds. The management implications of the results and recommendations for further studies are also considered.
Recovery and Viability of Edwardsiella ictaluri from Great Blue Herons Ardea herodias Fed E. ictaluri‐Infected Channel Catfish Ictalurus punctatus Fingerlings
Authors: Waterstrat Paul R. , Dorr Brian , Glahn, and James F. , Tobin Mark E. 
Published: April 2007

Abstract.Feeding activities of great blue herons Ardea herodias in catfish ponds during outbreaks of enteric septicemia of catfish have been implicated as a mechanism for the transmission of the disease from infected to uninfected ponds. Although Edwardsiella ictaluri, the causative agent, has been identified in gastrointestinal tracts of great blue herons, the role of these birds as a vector of E. ictaluri is not well documented. The potential of these birds to contaminate catfish ponds with E. ictaluri was investigated by feeding captive herons over a 4‐d period with catfish fingerlings injected intraperitoneally with live E. ictaluri. Daily fecal samples, throat and rectal swabs, and feather samples were collected, cultured and examined for E. ictaluri using both a selective media and a monoclonal indirect fluorescent antibody test specific for E. ictaluri. Gastrointestinal tracts sampled at the conclusion of the feeding trial were similarly examined. While E. ictaluri was detected using the indirect fluorescent antibody test, no viable E. ictaluri was cultured from either feces, gastrointestinal tracts or feathers. Growth of E. ictaluri was not observed at 40 C, the rectal temperature observed in captive great blue herons. Prior incubation at 40 C suppressed the growth of E. ictaluri at 24 C, an optimal temperature for growth of this bacterium. These results indicate that great blue herons appear to play little or no role in the transmission of E. ictaluri among catfish ponds.