bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appropriate Timing of Supplemental Feeding for Production of Nile Tilapia, Silver Carp, and Common Carp in Fertilized Polyculture Ponds
Authors: Abdelghany Ali E. , Ayyat Mohamed‐Salah , Ahmad Mohammed H. 
Published: April 2007

AbstractIn an attempt to identify appropriate times for initial application of supplemental feed in polyculture fertilized fish production earthen ponds, a study was conducted for 19 wk to establish the growth performance, yield, survival, and body composition of Nile tilapia, common carp, and silver carp as influenced by four different feeding regimens (treatments). The four treatments were: 1) supplemental feeding beginning at onset of the experiment (T‐I) (control treatment); 2) 6‐wk delay of feeding after fish stocking (T‐II); 3) 13‐wk delay of feeding after fish stocking (T‐III), and 4) no supplemental feed application (T‐IV). Two ponds were assigned to each treatment and each pond was stocked with a similar number and weight of each fish species. A commercial pelleted fish feed (25% protein) was used to feed fish in T‐I, T‐II, and T‐III at 3% of their body weight, twice a day. At the end of the experiment, fish species (except for silver carp) in T‐II showed weight gain, growth rates, and yields significantly higher than fish in T‐III or T‐IV. Also, the total fish production and net profit in T‐II were significantly higher than in T‐III or T‐IV. Fish species in T‐II showed weight gain, growth rates, survival rates, and yields similar to those of T‐I (control treatment) with no significant differences. The amount of feed consumed by fish in T‐II was reduced by approximately 7.3% compared to that consumed by fish at T‐I. Moreover, there was increase in th net profit in T‐II by 4.8% over that achieved in T‐I. Therefore, T‐II appears to be the most appropriate among the tested feeding treatments and recommended for use in order to achieve the best growth, production, and net profit.
Effects of Feeding Rate and Feeding Frequency on Survival, Growth, and Body Composition of Ayu Post‐Larvae Plecoglossus altivelis
Authors: Cho Sung Hwoan , Lim Young Soo , Lee Jong Ha , Lee Jong Kwan , Park Sangun , Lee Sang Min 
Published: April 2007

AbstractThe effects of feeding rate and feeding frequency on survival, growth and body composition of ayu post‐larvae (0.15 g in body weight and 3.5 cm in total length) were investigated in this study. A factorial experimental design of two feeding rates (3 and 6% of body weight of fish per meal) five feeding frequencies (one meal in 2 d, one meal a day, two meals a day, four meals a day, and six meals a day) with three replicates was used. Survival of ayu post‐larvae was significantly (P 0.05) affected by feeding frequency but not by feeding rate. Survival of ayu improved linearly with feeding frequency at both feeding rates. Weight and length gains and specific growth rate (SGR) of ayu was significantly (P 0.05) affected by feeding frequency but not by feeding rate, with weight and length gains and SGR linearly elevated with increasing feeding frequency at both feeding rates. The greatest weight and length gains were observed in fish receiving six meals daily at both feeding rates; however, no significant difference in weight gain was observed among two, four, and six meals a day, or in length gain between four and six meals a day. Feed efficiency ratio (FER) was significantly (P 0.05) affected by both feeding rate and feeding frequency. FER linearly decreased with feeding frequency at both feeding rates or feeding rate in the same feeding frequency. When the total daily amount of feed supply was constant with various feeding frequencies at different feeding rates (one meal a day at 3% feeding rate and one meal in 2 d at 6% feeding rate, two meals a day at 3% feeding rate and one meal a day at 6% feeding rate, or four meals a day at 3% feeding rate and two meals a day at 6% feeding rate), improvement in survival, weight and length gains, and SGR was observed in fish with higher feeding frequency at lower feeding rate. Moisture, protein, and lipid content of fish were not significantly (P > 0.05) affected by either feeding rate or feeding frequency. However, lipid content of ayu linearly increased with feeding frequency at 6% feeding rate. The highest body lipid content was observed in fish receiving six meals daily at both feeding rates. Ash content of fish was significantly (P 0.05) affected by feeding frequency but not by feeding rate. Based on performance of ayu, it can be concluded that optimum feeding rate and feeding frequency for ayu post‐larvae (an initial weight of 0.15 g) were 3% per meal and four meals a day, respectively, under these experimental conditions.
Effect of Dietary Protein Concentration and Stocking Density on Production Characteristics of Pond‐Raised Channel Catfish Ictalurus punctatus
Authors: Li Menghe H. , Mannning Bruce B. , Robinson Edwin H. , Bosworth Brian G. 
Published: April 2007

AbstractDiets containing 28% and 32% crude protein were compared for pond‐raised channel catfish Ictalurus punctatus stocked at densities of 14,820, 29,640, or 44,460 fish/ha. Fingerling channel catfish with average initial weight of 48.5 g/fish were stocked into 30 0.04‐ha ponds. Five ponds were randomly allotted for each dietary protein ± stocking density combination. Fish were fed once daily to satiation for two growing seasons. There were no interactions between dietary protein concentration and stocking density for any variables. Dietary protein concentrations (28% or 32%) did not affect net production, feed consumption and weight gain per fish, feed conversion ratio, survival, processing yields, fillet moisture, protein and ash concentrations, or pond water ammonia and nitrite concentrations. Fish fed the 32% protein diet had slightly but significantly lower levels of visceral and fillet fat than fish fed the 28% protein diet. As stocking density increased, net production increased, while weight gain of individual fish, feed efficiency, and survival decreased. Stocking densities did not affect processing yield and fillet composition of the fish. Although highly variable among different ponds and weekly measurements, ponds stocked at the highest density exhibited higher average levels of total ammonia‐nitrogen (TAN) and nitrite‐nitrogen (NO2‐N) than ponds stocked at lower densities. However, stocking density had no significant effect on un‐ionized ammonia‐nitrogen (NH3‐N) concentrations, calculated based on water temperature, pH, and TAN. By comparing to the reported critical concentration, a threshold below which is considered not harmful to the fish, these potentially toxic nitrogenous compounds in the pond water were generally in the range acceptable for channel catfish. It appears that a 28% protein diet can provide equivalent net production, feed efficiency, and processing yields as a 32% protein diet for channel catfish raised in ponds from advanced fingerlings to marketable size at densities varying from 14,820 to 44,460 fish/ha under single‐batch cropping systems. Optimum dietary protein concentration for pond‐raised channel catfish does not appear to be affected by stocking density.
Effects of Yucca shidigera Extract on Growth, Nitrogen Retention, Ammonia Excretion, and Toxicity in Channel Catfish Ictalurus punctatus and Hybrid Tilapia Oreochromis mossambicus × O. niloticus
Authors: Kelly Anita M. , Kohler Christopher C. 
Published: April 2007

AbstractNitrogenous waste control in aquaculture systems is necessary to maintain healthy animals and to meet effluent standards. Decreased ammonia production has been attained in traditional livestock production systems by adding extracts of Yucca shidigera to the feed or storage lagoon system. An extract of Yucca shidigera was fed to post yolk‐sac and juvenile channel catfish Ictalurus punctatus and hybrid tilapia Oreochrornis mossambicus × O. niloticus to determine the effects on growth, nitrogen retention, ammonia excretion, and toxicity. Post yolk‐sac channel catfish fry fed the 1.0‐g yucca extract/kg as an agar coating were the only group of experimental organisms that had significantly greater weight gains compared to the control and 0.5‐g yucca extract/kg diet groups after 12 wk. Significantly lower fecal nitrogen concentrations were obtained from catfish fed diets containing yucca extract compared to the control groups, although no differences between fecal nitrogen concentrations for catfish fed diets with either 0.5‐g or 1.0‐g yucca extract/kg diet occurred. Ammonia excretion rates were significantly lower for catfish fed diets containing yucca extract compared to the control group. Accordingly, fish fed diets containing the yucca extract had significantly greater whole‐body protein composition, while lipid levels were significantly lower. No significant differences in proximate composition occurred for fish fed any of the diets containing yucca extract, though growth rates were significantly higher than the controls. This study demonstrated that a yucca extract can be used in the diet of channel catfish, and increased growth and decreased ammonia concentrations can be obtained in rearing systems.
Ultrasound Enhanced Immersion Protocols for Masculinization of Nile Tilapia, Oreochromis niloticus
Authors: Bart Amrit N. , Athauda A. R. S. B. , Fitzpatrick Martin S. , Contreras‐Sanchez Wilfrido M. 
Published: April 2007

AbstractAndrogen immersion protocols have been unsuccessful in consistently producing all‐male tilapia at a high enough ratio for them to be commercially viable. This study explored the use of ultrasound to improve on the results of previous immersion studies. Variables tested include two hormones (trenbolone acetate‐TBA and 17α‐methyldihydrotestoterone‐MDHT) at two concentrations (100 and 250 μg/L) and with or without ultrasound (cavitation level). All hormone treatments with ultrasound and non‐ultrasound resulted in significantly higher masculinization than the appropriate controls (P < 0.05). Among pairs of treatments of the same hormone at the same dose, all ultrasound treatments resulted in significantly higher number of males compared with non‐ultrasound treatments with the exception of MDHT 250 μg/L (P 0.05). Comparing across all ultrasound treatments, TBA 250 μg/L with ultrasound had higher masculinization than all the other ultrasound treatments (P 0.05). Comparing across all non‐ultrasound treatments, TBA 250 μg/L had higher (P 0.05) masculinization than MDHT 100 μg/L and TBA 100 μg/L with non‐ultrasound. Two of the three replicates of TBA 250 μg/L ultrasound treatment resulted in 100% males and the highest mean percentage (98%) of males. This study thus demonstrated the potential of a short‐term immersion protocol using ultrasound to more predictably produce all‐male, commercially viable tilapia seed.
Possible Effects of Sodium Chloride Treatment on Quality of Effluents from Alabama Channel Catfish Ponds
Authors: Sipauaba Tavares Luacia H. , Boyd Claude E. 
Published: April 2007

AbstractChannel catfish ponds are treated with salt (sodium chloride) to increase chloride concentration and prevent nitrite toxicity in fish. A survey indicated that most farmers try to maintain chloride concentration of 50 to 100 mg/L in ponds by annual salt applications. Averages and standard deviations for selected water quality variables in salt‐treated ponds were as follows: chloride. 87.2 ± 37.5 mg/L; total dissolved solids (TDS), 336 ± 96 mg/L; specific conductance, 512 ± 164 μmhos/cm. Maximum values were 189 mg/L for chloride, 481 mg/L for TDS, and 825 μmhos/cm for specific conductance. Good correlations between specific conductance values and both chloride and TDS concentrations suggest that specific conductance can be a rapid method for estimating concentrations of these two variables in surface water. The maximum limit for chloride concentration in Alabama streams allowed by the Alabama Department of Environmental Management is 230 mg/L. The usual recommended upper limit of TDS for protection of aquatic life in freshwater streams is 1,000 mg/L. Based on the observed relationship between TDS concentration and specific conductance in Alabama catfish ponds, 1,000 mg/L TDS corresponds to 1,733 μmhos/cm specific conductance. It is unlikely that effluents from salttreated catfish ponds would violate the in‐stream chloride standard of 230 mg/L or harm aquatic life in streanis. Nevertheless, chloride concentrations in ponds should be measured before salt application as a safe guard against excessive salt application and chloride concentrations above the in‐stream chloride standard.
Genetic Analyses for TSV‐Susceptible and TSV‐Resistant Pacific White Shrimp Litopenaeus vannamei using M1 Microsatellite
Authors: Xu Zhenkang , Wyrzykowski Jennifer , Alcivar‐Warren Acacia , Moss Shaun M. , Argue Brad J. , Arce Steve M. , Traub Monica , Calderon Fernanda R. O. , Lotz Jeffrey , Breland Verlee 
Published: April 2007

AbstractAllelic frequency differences at the highly polymorphic MI microsatellite of B20 locus were examined in Taura Syndrome Virus (TSV)‐susceptible (Kona) and TSV‐resistant (Select) lines of Pacific white shrimp Litopenaeus vannamei. DNA was screened from 1,009 cultured L. vannamei, 166 from the Kona line and 843 (97 broodstock and 746 offspring) from the Select line. A total of 34 different MI alleles were found, 41.2% of which were shared by the two lines, and 58.2% were unique to either line. Only seven (20.6%) of the 34 alleles had similar frequencies in the two lines. The most frequent (22.4%) allele in the Select line (218 bp) was absent from the Kona line. The most frequent (9.6%) allele in the Kona line (236 bp) was not observed in the Select line. Significant genetic differentiation between the two lines was shown using contingency table analysis (X2= 891.20, df = 33, P < 0.0001), the exact test (P < 0.00001), and Fst, analysis (0.06). Comparison of MI allele frequencies between the TSVresistant Select and TSV‐susceptible Kona lines and between the top 12.5% (Top Select) and the bottom 12.5% (Bottom Select) surviving families to TSV challenge in the Select line suggested associations of MI alleles with TSV resistance. These observations suggest testable hypotheses in future experiments aimed at finding genetic markers associated with resistance to TSV and markers that could be used for marker‐assisted selection of broodstock.
Expression of Family Differences through Within‐Lot Competition in Juvenile Rainbow TroutOncorhynchus mykiss
Authors: Blanc J. M. , Poisson H. 
Published: April 2007

AbstractEffects of family differences on survival, length, weight, growth, and pyloric caeca number for juvenile rainbow troutOncorhynchus mykisswere analyzed in binary associations of families (sib‐groups), using a genetic variant with “golden” phenotype as a marker. In such an association, the performance of a family i mixed with family j depends on its own ability (P1), on the influence of the associated family (AJ), and on possible effects specific to the ij association. Experimental results showed that specific effects were negligible, and that the AJinfluence was significant on body length and weight (after 3 mo of age), and opposite to the PJvalue of the same family. Growth showed the same feature, but short of significance. The genetic marker caused some detrimental pleiotropic effects on length, weight, and growth, and some limited interactions with the familial factors studied. Results suggest that, when practicing selection, aquaculturists should prevent early size differences from becoming enhanced by competition, and should consider periodic size grading and multi‐step selection. Results also suggest that family interactions should be accounted for when analyzing mixed‐family genetic evaluation data.
Effects of Added Shelter and Stocking Density on Growth of Sleepy Cod Oxyeleotris lineolatus in Ponds
Authors: Herbert Brett W. , Graham Peter A. , Foster Scot D. 
Published: April 2007

AbstractSleepy cod Oxyeleotris lineolatus is a species of freshwater goby in demand in Australian markets by consumers of Asian origin. It is related to marble goby Oxyeleotris marmoratus, the most expensive freshwater food fish in Asia, which is cultured throughout southeast Asia in ponds and cages. The performance of sleepy cod in culture conditions was investigated to assess the viability of farming them in northern Australia. Sleepy cod fingerlings (62.8 ± 0.8 mm total length and 2.56 ± 0.095 g) were stocked into experimental ponds at 32,857 fish/ha, and grown out for 8 mo. Shelter was provided in each of three replicate ponds and was absent in three control ponds. The provision of shelter in juvenile growout was found to be of no benefit, although fish in ponds provided with shelter weighed slightly more per unit length than fish in ponds without shelter. Cannibalism was not a problem in growout, and survival was close to 100%. After the shelter trial was completed, fish were graded into large and small classes (three replicates of each), and grown out without shelter at the same density for 158 d. Following that, fish were again graded, and the largest 30% retained from growout at a density of 8,857 fish/ha (large, 198 ± 6.44 g) or 10,000 fish/ha (small, 48.9 ± 1.27 g). These were grown out for 188 d. Growth of selected stock at low densities was slower than earlier growth rates, although smaller fish gained weight more rapidly than larger fish. Growth rates were better than the only published data for marble goby. Further investigation into high density culture and different genotypes of sleepy cod needs to be undertaken to determine the viability of pond culture.
Acute and Chronic Effects of Nitrite on White Shrimp, Litopenaeus vannamei, Cultured in Low‐Salinity Brackish Water
Authors: Gross Amit , Abutbul Shal , Zilberg Dlna 
Published: April 2007

AbstractThe marine white shrimp Litopenaeus vannamei is widely cultured. Recently, farmers have begun to culture this shrimp in low‐salinity brackish water (< 6 g/L). The intensification of shrimp culture often results in occurrences of elevated nitrite concentration during the growing season. Nitrite is toxic to shrimp and exposure to high concentrations may cause retarded growth and mortalities. The current study was aimed at investigating the acute and chronic toxicity of nitrite to L. vannamei grown in low‐salinity (2 g/L) brackish water. Studies of the 96‐h EC50 and LC50 values of nitrite were performed to determine the acute toxicity, and an aquarium growth study (2 d post exposure to elevated nitrite concentrations) was conducted to evaluate the chronic effects of nitrite on shrimp production. The 96‐h EC50 and LC50 values for juvenile L. vannamei grown in water of 2 g/L salinity was about 9 mg/L NO2‐N, suggesting a safe concentration for shrimp production in ponds to be less than 0.45 mgIL NO2‐N. Exposing shrimp to nitrite concentration of 4 mg/L for 2 d reduced their growth but did not affect their survival.
Factors Affecting Sediment Oxygen Demand in Commercial Channel Catfish Ponds
Authors: Steeby James A. , Hargreaves John A. , Tucker Craig S. 
Published: April 2007

AbstractSediment oxygen demand (SOD) measured in 45 commercial channel catfish ponds in northwest Mississippi using in situ respirometry (N = 167) ranged from 63 to 1,038 mg/m2 per h. Mean SOD in this study (359 mg/m2 per h) was greater than that reported previously for catfish ponds but was similar to SOD in semi‐intensive marine shrimp ponds. Nine variables were selected and measured to assess their relative importance in accounting for variation in SOD. Six variables were included in multiple regression models that explained slightly more than half of the variation in SOD. These variables were: dissolved oxygen concentration at the beginning of respirometry incubation:, particulate organic matter concentration in water above the sediment surface: organic carbon concentration at the immediate sediment‐water interface (flocculent or F‐layer) combined with the upper 2 cm of sediment (S‐layer); organic carbon concentration in the mature (M) underlying sediment layer: water temperature: and total depth of accumulated sediment. Sediment oxygen demand was most sensitive to changes in dissolved oxygen concentration in the overlying water, particulate organic matter concentration in the water, and the concentration of organic carbon in the combined flocculent and upper sediment (F+S) layer. Models for SOD in this research predict that the mass of sediment below the upper 2‐cm surface layer on average contributes only ∼20% of total SOD. Stratification and normal daily fluctuation of dissolved oxygen concentration in eutrophic culture ponds likely limit expression of sediment oxygen demand. Maintaining aerobic conditions at the sediment‐water interface will minimize accumulation of organic matter in pond sediment.
Threadfin Shad Dorosoma petenense Effects on Water Quality, Phytoplankton, and Channel Catfish Production in Ponds
Authors: Ciudice Gina M. Lo , Bayne David R. , Popma Thomas J. 
Published: April 2007

AbstractThreadfin shad Dorosoma petenense are often stocked into commercial catfish ponds for biological control of algae. It is thought that the fish will alter the phytoplankton community, improve water quality, and enhance channel catfish production. Co‐stocking of shad and catfish is a common practice, although there is limited information regarding the effects of threadfin shad on pond dynamics and catfish production. To evaluate the influence of shad in catfish ponds, this study was conducted in ten 0.04‐ha experimental earthen ponds near Auburn, Alabama. All ponds were stocked in April with 600 fingerling channel catfish Ictal‐urus punctatus (13,200/ha) with a mean length of 10.4 cm (4.1 in). Additionally, five of these ponds were randomly chosen and stocked with 70 adult threadfin shad (1,750/ha) weighing a total of 3.3 kg (16.5 kg/ha). At harvest in November, an average of 1,284 threadfin shad (32,100/ha), weighing a total of 55 kg (1,375 kg/ha) were collected from each shad pond. Water quality was improved with the addition of threadfin shad to channel catfish ponds. Mean total ammonia‐nitrogen was significantly lower and less variable in the shad treatment. Observed mean nitrite concentrations, though not significant, were lower in the shad treatment. The phytoplankton community of the shad treatment had significantly higher density, more taxa, and smaller organisms. Pond water in the shad treatment had higher projected early morning dissolved oxygen levels requiring less aeration. Channel catfish had significantly higher survival in the shad treatment, furthermore, though not statistically significant, observed mean fish production was higher and feed conversion ratio was lower than in the no‐shad treatment.