bluuebunny/crossref_metadata_2025 huggingface dataset:
A SURVEY OF THE PREVALENCE OF SALMONELLA AND OTHER ENTERIC PATHOGENS IN A COMMERCIAL POULTRY FEED MILL
Authors: WHYTE PAUL , McGILL KEVINA , COLLINS JOHN DANIEL
Published: April 2007

A study of the prevalences of Salmonella, Listeria and thermophilic campylobacters in a dedicated commercial poultry feed mill was undertaken. Salmonella was frequently recovered in samples taken in the preheat and postheat treatment areas of the mill with the overall percentage of samples positive found to be 18.8% and 22.6%, respectively. Feed ingredients and dust collected in the preheat treatment locations within the mill were frequently contaminated with Salmonella (11.8% and 33.3% of samples, respectively). High prevalences of Salmonella were also detected in dust samples (24.2%) obtained from the postheat treatment area of the mill and from feed delivery vehicles (57.1%).

Listeria was also recovered from samples at pre‐ and postheat treatment areas within the mill with overall isolation rates of 14.1% and 18.5% observed, respectively. The most frequently observed species of Listeria recovered from samples in both areas within the mill was L. innocua, L. monocytogenes, L. grayi and L. welshimeri.

No thermophilic campylobacters were recovered from any of the samples analyzed in the current study.
MODELING TEMPERATURE, pH, NaCl, NITRITE AND LACTATE ON THE SURVIVAL OF ESCHERICHIA COLI O157:H7 IN BROTH
Authors: WHITING R.C. , GOLDEN M.H.
Published: April 2007

A model was developed to estimate the survival times for a four‐strain cocktail of Escherichia coli O157:H7 in BHI broths with pH values from 3.5 to 7.0, NaCl from 0.5 to 15%, Na lactate from 0.0 to 2.0% and NaNO2 from 0 to 75 ppm. Broths were stored between 4 and 37C for up to 6 months. Samples were removed and enumerated at appropriate intervals. A primary level model with a shoulder period (no decline) and a subsequent log‐linear decline was fitted to the survival data and the times for 3, 4, 5, and 6 log10‐units of decline determined. A secondary level second‐order regression equation with the environmental conditions and declines being the independent variables was fitted to the survival times. Confidence limits about the estimated mean were also estimated. In foods with equivalent conditions that do not permit E. coli O157:H7 growth, this model provides an initial estimate of the survival times.
CHALLENGE STUDIES WITH PROTEOLYTIC CLOSTRIDIUM BOTULINUM IN YEAST AND CHEMICALLY LEAVENED CRUMPETS PACKAGED UNDER MODIFIED ATMOSPHERES
Authors: DAIFAS DAPHNE PHILLIPS , SMITH JAMES P. , BLANCHFIELD BURKE , CADIEUX BRIGITTE , SANDERS GREG , AUSTIN JOHN W.
Published: April 2007

Challenge studies were done with proteolytic Clostridium botulinum (103 spores/g) in yeast‐and chemical‐leavened crumpets (50‐g) packaged in air with an ethanol vapor (2‐G Ethicap®) generator or in 100% CO2 and stored at ambient temperature (25C) for 30 days. Neurotoxin was detected in all gas‐ (CO2) packaged crumpets after 5 days regardless of the method of leavening. While neurotoxin was delayed for 10 days in chemical‐leavened Ethicap®‐packaged crumpets, it was not detected in any similarly packaged yeast‐leavened crumpets throughout storage. This inhibition of growth and neurotoxin production by C. botulinum was attributed to the production of ethanol by Saccharomyces cerevisiae in the yeast leavened crumpets, in conjunction with the ethanol vapor generated by the Ethicap® sachets (2‐G), to levels to inhibitory to the growth of C. botulinum (>2.8% v/v). Subsequent challenge studies in sterile crumpets inoculated with either C. botulinum (103 spores/g) or a co‐inoculum of C. botulinum (103 spores/g) and S. cerevisiae (105 CFU/g) confirmed the significant role (p<0.001) of S. cerevisiae in enhancing the antibotulinal efficacy of ethanol vapor. These studies showed that the method of crumpet leavening could have a profound effect on the growth of and neurotoxin production by C. botulinum in crumpets packaged under modified atmospheres.
NOVEL NONTHERMAL METHODS TO REDUCE VIBRIO VULNIFICUS IN RAW OYSTERS
Authors: BORAZJANI ABDOLSAMAD , ANDREWS LINDA S. , VEAL CHARLES D.
Published: April 2007

Vibrio vulnificus is a foodborne pathogen associated with consumption of raw oyster. No scientific data is available on postharvest treatments of oyster by ultrasound, ozone, and organic acids. This study was designed to investigate the effects of these treatments on inactivation of V. vulnificus naturally present in the in‐shell or half‐shelled oysters. In in‐shell oysters, these treatments were not effective in reducing the number of this pathogen. Half‐shelled oysters treated with ultrasound, and ozone in 2% saline for 30 min had 1 and 1.5 log less V. vulnificus, respectively (p<0.05). Treatment of half‐shelled oysters by 50 and 100% lemon juice, 5% citric acid, 10% citric acid, or vinegar for 30 min resulted in a significant reduction (2–4 log) in the numbers of V. vulnificus (p<0.05). Although these methods significantly reduced the population of V. vulnificus in raw oysters, they were not able to reduce the numbers of this pathogen to acceptable level (<3 MPN/g).
THE OCCURRENCE, HEMOLYTIC ACTIVITY AND ANTIBIOTIC SUSCEPTIBILITY OF MOTILE AEROMONAS SPP. ISOLATED FROM MEAT AND MILK SAMPLES IN TURKEY
Authors: YUCEL NIHAL , ÇITAK SUMRU
Published: April 2007

Research was carried out to detect the incidence of motile Aeromonas species (A. hydrophila, A. caviae, A. sobria) in a variety of raw meat products (minced meat and chicken) and milk samples (raw and pasteurized) commonly consumed in Ankara. Motile Aeromonas species were isolated from 51.8% of samples detected; these were 40 (67.7%) of the 59 samples of minced meat, 20 (86.9%) of the 23 samples of chicken, 75 (47.7%) of the 157 samples of raw milk and 5 (16.0%) of the 31 samples of pasteurized milk. The dominant species were A.hydrophila and A.sobria in the meat samples, while A. hydrophila was the only isolated species in the milk samples. The strains identified as A. sobria or A. hydrophila were the stronger producers of hemolysin, whereas the A. caviae strains were nonhemolytic. The resistance of isolates to eight antibiotics was determined using the Kirby Bauer disc diffusion assay (Ciprofloxacin, Ceftazidime, Ampicillin, Cefixime, Cefoperazone, Erythromycin, Trimethoprim/sulfamethoxazole, Ceftriaxone). All aeromonads isolates (100%) were susceptible to ciprofloxacin but resistant to (100%) ampicillin and erythromycin. We found out that motile Aeromonas species are commonly present in milk and meat samples investigated in Turkey, which may pose a health problem to consumer. In addition, ciprofloxacin, cefoperozone, and ceftriaxone are suitable drugs that can be used in the treatment of Aeromonas‐associated infections, particularly in the immunocompromised, elderly people and young children.
INACTIVATION OF BACTERIAL SPORES BY COMBINED ACTION OF HYDROSTATIC PRESSURE AND BACTERIOCINS IN ROAST BEEF
Authors: KALCHAYANAND N. , DUNNE C.P. , SIKES A. , RAY B.
Published: April 2007

Foodborne bacterial spores are normally resistant to high hydrostatic pressure; however, at moderate pressure, they can be induced to germinate and outgrow. At this stage, they can be killed by bacteriocin‐based biopreservatives (BP‐containing pediocin and nisin at 3:7 ratio; BPX, BP + 100 μg/mL lysozyme; BPY, BPX+ 500 μg/mL Na‐EDTA). Based on this principle, spores of the meat spoilage organism, Clostridium laramie (1–2 × 102 spores/bag) alone or a mixture of four clostridial spores (5 × 103 spores/bag), Clostridium sporogenes, Clostridium perfringens, Clostridium tertium, and Clostridium laramie, were inoculated in roast beef in the presence of 5000 AU/g of bacteriocin‐based biopreservatives. The roast beef samples were subjected to hydrostatic pressure (HP) at 345 MPa for 5 min at 60C and stored at 4 or 12C for 84 days or at 25C for 7 days. The HP treatment of roast beef samples inoculated with a mixture of clostridial spores could be stored for 42 days at 4C. The HP in combination with either BPX or BPY extended the shelf‐life of roast beef up to 7 days at 25C. The combined treatment of HP and BP controlled the growth of C. laramie spores and extended the shelf‐life of roast beef for 84 days when stored at 4C.
SURVIVAL OF LISTERIA INNOCUA IN APPLE JUICE AS AFFECTED BY VANILLIN OR POTASSIUM SORBATE
Authors: CORTE FEDERICO V. , DE FABRIZIO SUSANA V. , SALVATORI DANIELA M. , ALZAMORA STELLA M.
Published: April 2007

Survival of stationary phase Listeria innocua (as surrogate microorganism for L. monocytogenes) inoculated in apple juice (pH 3.3 or 3.8) supplemented with vanillin (1,500 ppm or 3,000 ppm) or potassium sorbate (500 ppm or 1,000 ppm) and stored at room temperature was studied. L. innocua survived in apple juice without the preservatives at pH 3.3 or 3.8, with minimal population reductions. In the juices with the incorporation of potassium sorbate or vanillin, L. innocua behavior depended on the pH value, the type of antimicrobial and its concentration. At pH 3.3, the presence of vanillin (3,000 ppm) or potassium sorbate (1,000 ppm or 500 ppm) decreased L. innocua counts, with population reductions ranging from 4 to 5 log cycles after a 4 h – 8 h exposure at 30C. However, at pH 3.8, L. innocua showed sensitivity only to 3,000 ppm vanillin. Survival curves were successfully fitted using a Weibull type distribution of resistances.

The results suggest that the use of potassium sorbate or vanillin could prevent the survival of L. innocua in contaminated unpasteurized and pasteurized apple juice. Vanillin, a natural antimicrobial, would be particularly suitable as an antilisterial additive for less acidic apple juice.
The Effect of Five Stocking Densities on Growth and Yield of Red Swamp Crawfish Procambarus clarkii
Authors: Lutz CHarles G. , Wolters William R.
Published: April 2007

A 34‐day study was conducted to estimate the effect of stocking density on growth, biomass, and yield of harvestable animals in red swamp crawfish, Procambarus clarkii (Girard). Juvenile crawfish were stocked at l, 2, 4, 8, and 16 crawfish per m2 into plastic‐lined metal pools planted with rice (Oryza sativa) with three replicate pools at each density. Crawfish averaged 35 ± 1.5 mm (SE) total length at the time of stocking.

Growth in total length and weight was significantly affected by density (P < 0.01), ranging from 91.5 mm and 20.7 g for crawfish stocked at 1 per m2 to 62.5 mm and 6.3 g for crawfish stocked at 16 per m2. The total crawfish biomass ranged from 20.7 g per m2 for crawfish stocked at 1 per m2 to 88.7 g per m2 at 16 per m2. The portion of that biomass made up of harvestable sized animals (>75 mm total length) ranged from 100% at 1 per m2 to 0.7% at 16 per m2. Gross revenues per ha were projected for crawfish yields at each stocking density with and without a graded product.
Shipping of Penaeid Broodstock: Water Quality Limitations and Control During 24 Hour Shipments
Authors: Robertson Lori , Bray William A. , Lawrence Addison L.
Published: April 2007

Shipping trials were conducted with adult Penaeus setiferus to determine the effect of 24 hour closed shipments on water quality, to evaluate methods of reducing water quality deterioration and to maximize packing density (biomass). Other trials were undertaken with juvenile P. setiferus and adult P. vannamei for comparison. The method utilized 8 L seawater chilled to 18–19 C, inside doubled polyethylene bags held in a Styrofoam box (42 × 42 × 23 cm deep). Gaseous O2 was injected into the water to 8 ppm (for standardization) and into the space above the water. Super‐saturation of dissolved oxygen (>20 ppm for 24 hours) had no adverse effect on survival. Initial trials resulted in increased ammonia (from 0.1 to 4–6 ppm NH4‐N), increased carbon dioxide (from <2 to 80–100 ppm), increased temperature (from 18–19 to 25–26 C) and decreased pH (from 8.0 to 6.0–6.4). Increases in shipping density (number or biomass of shrimp per L seawater) further intensified water quality deterioration. Carbon dioxide (with concomitant pH decline) is implicated as the major limiting factor during 24 hour closed shipment. Ammonia accumulation was reduced or totally eliminated with addition of AmQuelΘ (Kordon, Inc, Hayward, California),2 depending on the dosage used. The buffer, Trizma® 8.3 (Sigma Chemical Co, St. Louis, Missouri),2 limited CO2 buildup and reduced pH decline. Maintenance of low temperature over 24 hours was enhanced with addition of a frozen cold pack placed over the shipping bags. However, the control of ammonia, pH and carbon dioxide by the addition of AmQuel and Trizma did not increase survival, possibly due to toxic effects of the chemicals.
Effects of Heavy Metals on the Hatching Rates of Brine Shrimp Artemia salina Cysts
Authors: Liu Ping‐Chung , Chen Jiann‐Chu
Published: April 2007

The effects of heavy metals (Hg2+, Cd2+, Co2+, Cr3+, Pb2+, Cu2+, Fe2+. Ni2+, Zn2+, Mn7+, Mn4+ and Mn2+) on the relative hatching percentage of brine shrimp, Artemia salina were assessed. Artemia salina cysts (San Francisco Bay Brand) hatched in seawater containing various heavy metal concentrations. After 48 hours, the number of hatched nauplii were counted. A negative linear relationship between hatching rate of Ariemia salina cysts and heavy metal concentration occurred, except copper which conformed to a cubic model. The relative toxicities of heavy metals on Artemia salina cysts were as follows (Cu2+, most toxic; Mn2+, least toxic): Cu2+ > Zn2+ > Ni2+ > Co2+ > Mn7+ > Cr3+ > Cd2+ > Fe2+ > Hg2+ > Mn4+ > Pb2+ > Mn2+.
Accumulation of Heavy Metals in the Nauplii of Artemia salina
Authors: Chen Jiann‐Chu , Lru Ping‐Chung
Published: April 2007

Artemia salina cysts (San Francisco Bay Brand) were exposed in seawater containing multiple concentrations of either a single heavy metal (Hg, Cu, Zn, Pb, Cd, Co, Ni, Cr, Mn and Fe) or combination of heavy metals. The heavy metal accumulation in Artemia nauplii increased linearly with an increase in the heavy metal concentration in water. The metals could be detected in nauplii exposed to a single heavy metal at dosages of 5 μg/L for Hg, Zn, Mn, Fe and Cu; 25 μg/L for Cd and Cr; 50 μg/L for Co; 100 mUg/L for Ni; and 250 μg/L for Pb. Cysts exposed to several heavy metal combinations had minimum effective dosages equal to or lower than the single heavy metals‐ 5 μg/L for Cu, Cr, Zn, Mn and Fe; 25 μg/L for Cd and Ni; 50 μg/L for Co; and 250 μg/L for Pb. The accumulation of Cu, Ni and Co by Artemiu nauplii did not differ for animals exposed to single or combined heavy metal solutions. Cr, Zn and Pb had a synergistic effect of heavy metal uptake in combined heavy metal element solutions, however, Fe, Cd and Mn had an antagonistic effect.
A 13C/12C Tracer Study of the Utilization of Presented Feed by a Commercially Important Shrimp Penaeus vannamei in a Pond Growout System1
Authors: Anderson Richard K. , Parker Patrick L. , Lawrence Addison
Published: April 2007

A study of added feed utilization by pond grown shrimp was done using seven feeds with different 13C/12C ratios, as expressed by δ13C. The pond shrimp did not track the δ13C value of the feed to the extent that tank grown shrimp did. For the seven pond experiments the δ13C data indicate that the added feed supplied between 23 and 47% of the growth carbon. This implies that between 53 and 77% of the growth is due to the grazing on pond biota. It is suggested that this experimental approach can be used to evaluate the relative contribution of presented dried feeds versus natural productivity in ponds as an aid to developing pond management strategies and optimum feeds.
Potential of New Strains of Marine and Inland Saline‐Adapted Microalgae for Aquaculture
Authors: Barclay W. R. , Terry K. L. , Nagle N. J. , Weissman J. C. , Goebel R. P.
Published: April 2007

Several problems currently limit the reliability of algal cultivation systems for the production of aquaculture feeds. Many of these problems may be eventually solved through research in culture system design and operation. However, research into the isolation and development of new strains of microalgae may also directly lead to improved system performance.

Through a collection and screening program aimed at isolating microalgae tolerant to high light, high salinity, and high temperatures, we have been able to isolate several new strains with enhanced production potential (30‐35 g/m2/d). The overall range of environmental tolerance exhibited by these strains may result in enhanced culture stability, leading to the high production rates.

The estimated costs of producing strains with these high production rates range from $1.18 to S1.71 per kg (unharvested), depending on the size of the production system. Total production costs for harvested algae (15% solids algal cell paste) range from $1.63 to $2.45 per kg. The major costs for producing harvested algae include the cost of CO2, as well as capital and operating costs for the harvesting systems.
Efficacy of Elevated Dietary Fluoride for the Control of Renibacterium salmoninarum Infection in Rainbow Trout Salmo gairdneri
Authors: Bowser Paul R. , Landy R. B. , Wooster G. A. , Babish J. G.
Published: April 2007

Laboratory studies were performed to evaluate the efficacy of dietary fluoride for the control of Renibacterium salmoninarum infection in rainbow trout and to determine potential dietary fluoride toxicity to the fish. Fish were fed diets containing fluoride (F), as NaF, to give doses of 0, 2, 4, 8, or 16 mg F/kg fish weight per day. Efficacy of fluoride for the control of bacterial kidney disease (BKD) was observed at 4, 8, and 16 mg/kg doses. No signs of toxicity due to dietary fluoride were observed in the fish.
Feasibility Study for Alternative Culture Species in Taiwan—Penaeus penicillatus
Authors: Liao I‐Chiu
Published: April 2007

Penueus monodon has become almost synonymous with aquaculture in Taiwan, indicating the level of commercial success it has attained over the past two decades. However, other species are being considered for future culture to diversify an industry overly dependent on one product, as well as to provide the market with an alternative commodity. This paper explores the feasibility of P. penicillatus as an alternative culture species in Taiwan.

P. penicillatus has seven merits that make it ideal for aquaculture: 1) P. penicillatus is comparatively resistant to low temperature. 2) It is a medium sized “white prawn” and is attractive to the consumer. 3) The migration behavior shows good possibilities for culture in sea water. 4) Wild spawners are abundant and natural, and induced spawning in captivity is relatively easy. 5) Larvae spontaneously spawned in captivity show good survival, existing on the natural food present in the pond. 6) It has a low protein requirement and has good growth in the early stages even at high stocking densities of 100–120 prawns/m2. 7) P. penicillutus grows to a comparatively uniform size. This paper also discusses some difficulties in the culture of this prawn.
Super Intensive Culture of Red‐Tailed Shrimp Penaeus penicillatus
Authors: Chen Jiann‐Chu , Liu Ping‐Chung , Lin Yao‐Tsu , Lee Chin‐Kai
Published: April 2007

Two continuous grow‐out experiments of red‐tailed shrimp Penueus penicillatus were conducted for one year in a super intensive system with a stocking density of 171 and 286 postlarvae/m2, respectively. The postlarval shrimp (Ph8–12) were cultured in three 0.14 ha earthen ponds with concrete dikes. The shrimp were fed with a commercially prepared feed four times a day. Water quality parameters from the second trial varied as follows: water temperature from 23.0 to 30.4 C, salinity from 15.33 to 21.00 ppt, dissolved oxygen (DO) from 3.47 to 7.34 mg/L, NH3‐N from 0.002 to 0.869 mg/L, nitrite‐N from 0.013 to 0.844 mg/L, and nitrate‐N from 0.021 to 1.795 mg/L. Ammonia‐N increased from 0.022 to 46.110 mg/L, while the pH declined from 8.12 to 7.32. Yield was 4,650 kg/0.42 ha from the first crop in 131 days and 5,160 kg/0.42 ha from the second crop in 141 days. The productivity of this system producing P. penicillatus was 11–12 tons/ha/crop.
Production Costs of Juvenile Penaeid Shrimp in an Intensive Greenhouse Raceway Nursery System
Authors: Juan Ya‐Sheng , Griffin Wade L. , Lawrence Addison L.
Published: April 2007

This analysis compared the use of an intensive nursery raceway system with direct stocking of post‐larval shrimp into growout ponds. The intensive raceway system allows two crops to be produced in Texas where only one crop is feasible with direct stocking. Both investment and operational costs are analyzed for three types of greenhouses and three types of raceways where the types vary in cost and lengths of life. Three growout pond stocking densities and two farm sizes were evaluated for each combination of greenhouse and raceway type. Investment costs ranged from $142,000 for the small farm using the least expensive greenhouse and raceway and utilizing the lowest stocking density, to about $2.3 million for the large farm using the most expensive greenhouse and raceway and the highest stocking density in the growout ponds. The operational cost was $7.60 and $9.71 respectively per 1,000 one gram juveniles produced. Under technology available at the time of this analysis, direct stocking growout ponds with PIS and producing one crop per year is more profitable than stocking one gram juveniles and producing two crops per year on the Texas coast.
Seasonal Variations in Fatty Acids of Striped Bass Morone saxatilis
Authors: Gallagher Margie L. , McLeod Susan H. , Rulifson Roger
Published: April 2007

The polyunsaturated fatty acids of the n‐3 family associated with fish and fish oils have been shown to have beneficial effects on prevention of heart disease in humans. However, in considering the potential health benefits of fish oil in human health, it is important to realize that the fatty acid composition and total lipid content of fish vary greatly. These variations may be due to species differences or variations within a species due to temperature, diet, developmental stage, sex or seasonal differences.

The purpose of the study described here was to determine the effects of season, size class, and sex on the Occurrence of individual fatty acids in striped bass (Morone saxrrtilis). Fish were collected in June, July, August, September, and October. Filets with skin were analyzed for total lipid content. Methyl esters of fatty acids were separated and identified using capillary gas chromatography. Total mean lipid varied from as low as 12% to as high as 30%. There were no significant changes in total crude lipid content due to month collected or sex. However, total lipid content of filets increased significantly (P ≤ 0.05) as size increased.

The fatty acids 18:1n–9 and 16:0 made up the majority (62%) of the fatty acids present in any season, size class, or sex. The monounsaturated fatty acids dominated in all fish. There were no significant differences in individual fatty acids due to sex. However, fish size had a significant influence on fatty acid composition. Overall, saturated fatty acids decreased as size increased, while polyunsaturated fatty acids increased or remained constant. There were no significant changes in mean percent saturated or monounsaturated fatty acids with respect to month when controlling for size. However, total percent polyunsaturated fatty acids decreased significantly in October compared to August and September. This overall decrease was due mainly to a decrease in 22:6n–3. Conversely there was a significant increase in 16:11n–9 in October. All other fatty acids remained constant. When data from this study were compared to fatty acid data from the literature, striped bass was not as good a source of 20:5n–3 and 22:61n–3 as sardines, anchovies or mackerel.
Chemical Decapsulation of Artemia franciscana Resting Cysts Does Not Necessarily Produce More Nauplii
Authors: Spotte Stephen , Anderson Gary
Published: April 2007

Decapsulation of Artemia spp. cysts in strong hypochlorite solutions reportedly increases the number of nauplii that hatch. Commercial cysts of Artemia franciscano were subjected to four decapsulation methods prior to hatching them in aerated seawater. Samples were removed from the hatch vessels every 5 h from 15 through 45 h, and fully hatched nauplii were counted. The experiment was performed three times. No significant difference was seen between mean numbers of control nauplii and nauplii obtained using the decapsulation method that yielded the best hatch: oxidation for 15 min in equal parts Clorox® and seawater plus 6 mL of a 40% NaOH solution, followed by reduction with 100 mL of 0.7 M sodium thiosulfate. A third treatment was inferior to either of these, and two others produced very low yields. It was concluded that of the methods evaluated, none is superior to no treatment at all, and some are clearly detrimental to developing Artemia embryos.
Nutritional Depletion of the Aquaculture Feed Organisms Euterpina acutifrons, Artemia sp. and Brachionus plicatilis During Starvation
Authors: Szyper James P.
Published: April 2007

The nutritional quality of the harpacticoid copepod Euterpina acutifrons, freshly‐hatched Artemita nauplii, juvenile and adult Artemia, and the rotifer Brachionus plictatilis, in fed and starved conditions, was evaluated through the use of ratios of dry weight to wet weight (DW/WW), ash‐free dry weight to dry weight (AFDW/DW), calories per mg ash‐free dry weight (cal/mg AFDW), and carbon to nitrogen by weight (C/N). E. acutifrons had in nearly all cases the highest values of DW/WW, AFDW/DW, and cal/mg AFDW. Calculated losses in caloric content per unit of wet weight (cal/mg WW) during one day's starvation were similar among species, ranging from 3 to 52 percent. C/N ratios were less variable, but also reflected starvation‐related changes indicating depletion of C relative to N, which is consistent With depletion of lipids and carbohydrates relative to protein.

Because little or no change in caloric density of organic material (cal/mg AFDW) was observed in any species under either condition, decreases in caloric content of wet weight or of individuals were due to decreases in DW/WW and AFDW/DW. Caloric content and carbon content were related by the factor 11.3 cal/mg C. Starvation‐related losses in the nutritional value of forage organisms can be important in larval rearing systems.
Genetics of Body Color in Tilapia mossambica
Authors: Tave Douglas , Rezk Mahmoud , Smitherman R. Oneal
Published: April 2007

Gold, bronze, and black (normal pigmentation) body colors in Tilapia mossambica are controlled by a single autosomal gene with incomplete dominant gene action: GG fish are black gg fish are gold; Gg fish are bronze. Because gold body color is produced by the recessive genotype, it is easy to produce and to maintain a truebreeding population of gold T. mossambica for commercial purposes. If all other colors are culled, the population will breed true, because gold × gold will always produce 100% gold offspring. The G gene will be a valuable genetic marker for many genetic studies, such as the production of gynogenetic T. mossambica.
The Effects of Salinity on Reproductive Performance of Florida Red Tilapia
Authors: Watanabe Wade O. , Burnett Kelly M. , Olla Bori L. , Wicklund Robert I.
Published: April 2007

The reproductive performance of yearling Florida red tilapia broodstock was studied in laboratory aquaria at salinities of 1 (freshwater), 9, 18, 27 and 36 ppt under controlled photoperiod (14 L:10 D) and temperature (28 C).

Spawning was observed at all salinities, although egg production per unit female weight at each spawn was significantly higher at 1 ppt than at higher salinities. An inhibitory effect of salinity on reproductive performance was evidenced by a trend toward lower fertilization, hatching, and survival of prejuveniles with increasing salinity. Fry production per unit female weight declined at salinities above 18 ppt. The results suggest that Florida red tilapia broodstock may be maintained under salinities as high as 18 ppt without impairing fry production, suggesting that hatchery production in brackishwater would be practical in areas where freshwater resources are limiting.
Comparative Production of Colossoma macropomum and Tilapia nilotica in Panama
Authors: Peralta Medardo , Teichert‐Coddington David R.
Published: April 2007

The production of Colossoma macropomum (tambaquí), a relatively little studied fish from the Amazon and Orinoco basins, was compared with that of Tilapita nilotica, a fish well known for its good production characteristics. The experimental design was randomized and arranged in 2 × 2 factorial with each species being tested at 2,500 and 10,000 fish/ha. Treatments were replicated three times. Fingerlings (22–31 g) were stocked into 870 m2 earthen ponds, fed a commercial diet (25% protein), and harvested after 129 days. Mean yield (kg/ha) for tilapia at high and low density was 3,361 and 917, respectively, and for colossoma was 3,682 and 977, respectively. The yield difference between species was not significant (P> 0.05) while the difference between densities was highly significant (P< 0.01). Although yield was not different for the species, tambaquí weight gain was significantly greater than that of adult tilapia because of reproduction in the tilapia ponds. Mean tilapia and tambaquí weight gains (g) for low density were 379 and 471, respectively, and 321 and 395, respectively, for high density. Increasing the stocking density fourfold resulted in an almost fourfold increase in net yield for both species, although individual weight gains were not significantly affected. There was no interaction between species and density for the production characteristics studied.

This study concluded that under culture conditions that included a short growth period, high quality rations, and stocking rates up to 10,000/ha, production of tambaquí was equal to, or better than that of tilapia. Also, stocking rates lower than 10,000/ha would result in lower yields of both species while not producing a significantly larger fish.
Evaluation of Three Feeds for Hatchery Rearing Channel Catfish Fry
Authors: Robinson Edwin H. , Steeby JamesA. , Brent J. Robert
Published: April 2007

Two 7 day feeding trials were conducted with channel catfish swim‐up fry to evaluate growth, feed conversion ratio, and body composition of fish fed one of the following feeds: salmon starter, catfish starter, or trout starter. Fish fed the salmon or trout starter feeds gained 50–75% more weight, converted feed more efficiently, and had higher body fat stores than fish fed the catfish starter feed. This may be related to the higher protein and energy content of these two feeds. It may be advantageous to feed salmonid starter feeds to hatchery reared catfish fry; however, it is not known whether or not the improved performance observed in the hatchery continues once the fish are stocked into nursery and grow out ponds.
A Parasitological Survey of Oysters Along Salinity Gradients in Coastal Louisiana
Authors: Gauthier Julie D. , Soniat Thomas M. , Rogers James S.
Published: April 2007

Oysters were collected along salinity gradients within four major oyster producing watersheds in Louisiana (Lake Calcasieu, Terrebonne Bay, Barataria Bay and Lake Borgne) and examined for parasites in relation to oyster condition and reproductive state. The percentage of Infection by Perkinsus marinus, Nematopsis prytherchi, N. ostrearum, Bucephalus cuculus, prokaryotic inclusion bodies, and ciliates was recorded for each site. Average pigment cell number, oyster condition, gonadal index, and the percentage of oysters with atrophic digestive diverticula were also determined.

In general, oysters experienced higher levels of parasitism in higher salinity waters. Perkinsus marinus Occurrence was correlated with salinity, an atrophied condition of the oysters, and Nematopsis spp. occurrence. Oysters in poor condition had higher concentrations of pigment cells, greater atrophy of the digestive diverticula, and increased parasitism by N. ostrearum.
A Promising New Chemotherapeutant for Use in Treatment of Fusarium solani Infections in Penaeid Shrimp
Authors: Bell Thomas A. , Lightner Don V. , Williams Rodney R.
Published: April 2007

A commercially available microbicide, composed of 5‐Chloro‐2‐methyl‐4‐isothiPzolin‐3‐one and 2‐methyl‐4‐isothiazolin‐3‐one, was tested for its in vivo effectiveness in controlling pathogenicity and mortalities in the marine shrimp Penaeus stylirostris, caused by the fungus Fusurium solani. Sub‐adult shrimp (100% with Fusurium lesions) were treated with the microbicide at levels of 5.0 and 7.5 ppm (Trial 1) and with 1.0, 2.5 and 5.0 ppm (Trial 2), and each compared to a non‐treated control. In Trial 1, treatments were administered during the first 9 days of the 22 day experiment, approximately every other day as 8 h static baths. The mean levels of Fusarium lesions on Day 22 for the 0, 5.0 and 7.5 ppm treatments were 87%, 25% and 13%, respectively. Statistically both levels of treatment (5.0 and 7.5 ppm) had significantly lower levels of Fusurium lesions when compared to the controls. In Trial 2, treatments of the microbicide were administered (8 h static bath) every seventh day over the course of the 64 day experiment. The Day 64 mean Fusarium lesion levels for the 0, 1.0, 2.5 and 5.0 ppm treatments were 54%, 59%, 10% and 7%, respectively. Treatment with 2.5 and 5.0 ppm reduced the prevalence of Fusarium lesions to statistically lower levels when compared to the 0 and 1.0 ppm treatments. The microbicide had earlier been reported to be highly toxic to fish. The use of activated charcoal filters on the microbicide‐treated effluent appeared to remove any residual compound from the water. The data in the present study indicate a possible inverse relationship between the level of “BG 101” and growth rate. The data from both trials suggest that periodic treatment over a longer test period could limit or eliminate Fusurium lesions, which are known to be the potential cause of substantial mortalities, particularly in captive broodstock populations.
Assessing Potential for Aquaculture Development with a Geographic Information System
Authors: Kapetsky James M. , Hill John M. , Worthy L. Dorsey , Evans David L.
Published: April 2007

Comprehensive analyses of aquaculture potential are required for policy formulation and planning for aquaculture development. A computer‐automated geographical information system (CIS) was assessed as a tool to analyze the complex spatial and attribute data sets needed to locate aquaculture potential. The state of Louisiana, USA, was the study area. Areas for the further development of catfish and crawfish culture and crawfish‐rice and crawfish‐grain sorghum double cropping were identified. The CIS showed that there were ample opportunities for the expansion of catfish farming on flatlands based on soil suitability and length of the growing season. Parishes in which crawfish are already raised occupy most of the best suited soils and include those with the longest growing seasons. The potential to further integrate crawfish with rice and with grain sorghum in double cropping systems was good. The results demonstrated that a GIS can be used to aid large‐area aquacultural development planning.
Effect of Dietary Lecithin in Combination with Casein or Crab Protein on Cholesterol Uptake and Transport in the Lobster Homarus americanus
Authors: Baum Nancy A. , Conklin Douglas E. , Chang Ernest S.
Published: April 2007

Purified diets, formulated with and without lecithin and containing either casein or a protein isolated from whole crab, were fed to juvenile lobsters. In order to examine the role of these dietary factors on cholesterol uptake and transport, levels of cholesterol were determined in serum, lipo‐protein fractions, tissues, and feces of juvenile lobsters fed the experimental diets. Lobsters fed diets supplemented with lecithin had significantly higher levels of serum and lipoprotein cholesterol than lobsters fed diets without supplemental lecithin regardless of the proteins used. Levels of fecal total cholesterol also were generally greater for lobsters fed lecithin‐supplemented diets. Tissue, serum, and fecal levels of intubated radiolabeled cholesterol, however, were not significantly different among diet groups, and apoprotein electrophoretic mobility was not affected by the choice of dietary protein.
Baker's Yeast as a Potential Substitute for Live Algae in Aquaculture Diets: Artemia as a Case Study
Authors: Coutteau Peter , Lavens Patrick , Sorgeloos Patrick
Published: April 2007

In this study baker's yeast was evaluated as a substitute for live Dunuliella tertiolecta algae in the culture of the brine shrimp Artemia. Consumption of fresh baker's yeast resulted in poor growth and survival of brine shrimp. However, the nutritional value of the yeast sigaificantly improved after complete removal of the yeast cell wall by enzymatic treatment. Baker's yeast was also made digestible for Artemia by simple chemical treatment which did not reduce rigidity of the yeast cell. The external mannoprotein layer of the yeast cell wall is probably the major barrier to digestion by Artemia. Chemically treated baker's yeast offers promising possibilities as a substitute for algal feeds in aquaculture.
Effects of Intraspecific Hybridization in Tilapia nilotica on Survival Under Ambient Winter Temperature in Alabama
Authors: Tave Douglas , Jayaprakas V. , Smitherman R. Oneal
Published: April 2007

Viability under ambient winter temperatures in Alabama was assessed for Auburn University‐Egypt and Auburn University‐Ivory Coast strains of Tilapia nilotica and their F1, F2, and four backcross hybrids. Egypt strain was more viable (P= 0.05) than Ivory Coast strain. Observed mean viabilities of the F1 hybrids were intermediate between those of the parental strains. Viabilities of the reciprocal F1 hybrids were not significantly different. Viabilities of the reciprocal F2 hybrids were not significantly different. Backcross hybrids that were produced by crossing F1 hybrid females to Egypt strain had a greater observed mean viability than those that were produced by crossing F1 hybrid females to Ivory Coast strain. Average viabilities of the parental strains, F1, F2, and backcross hybrids were not significantly different. Heterosis in F1, F2, and backcross hybrids was −1.39%,−0.82%, and −2.08%, respectively. Viability under ambient winter temperatures in Alabama in T. nilotica appears to be controlled by additive rather than by dominance effects, which means that selection rather than crossbreeding is the breeding technique that should be evaluated to improve this trait in T. nilotica.
Commercial‐Scale Production of Florida Red Tilapia Seed in Low‐ and Brackish‐Salinity Tanks
Authors: Ernst Douglas H. , Watanabe Wade O. , Ellingson Lisa J. , Wicklund Robert I. , Olla Bori L.
Published: April 2007

Commercial‐scale production of Florida red tilapia (Oreochromis sp.) seed (eggs, sacfry, and fry) under methods that minimized freshwater usage was studied on Lee Stocking Island, Bahamas. Comparisons of seed production by broodstock held in low‐salinity (LS = 5 ppt; mixed rain and ground water) and brackish‐salinity (BS = 18 ppt; mixed ground and sea water) tanks (34 m2) showed that seed production over an 8 month period was significantly greater in LS (77.7 seed/m2/ day) than in BS tanks (47.4 seed/m2/day), with average proportion of brooding females and number of seed per clutch being greater in LS (26.9% and 763) than in BS tanks (19.8% and 643). While LS seed production was among the highest reported values for tilapias, BS production was within reported ranges for fresh and low‐salinity tilapia hatcheries. Seed production per unit of low‐salinity water (i.e., rain and/or groundwater) consumed in both LS (7,262 seed/m3) and BS (5,337 seed/ m3) tanks exceeded reported values. The results support the feasibility of commercial‐scale production of Florida red tilapia seed under intensive methods and of salinities as high as 18 ppt in regions where fresh or low‐salinity water resources are limited.
Recruitment and Commercial Seed Procurement of the Blue Mussel Mytilus edulis in Maine
Authors: Newell Carter R. , Hidu H. , McAlice B. J. , Podniesinski G. , Short F. , Kindblom L.
Published: April 2007

A thorough understanding of recruitment in the blue mussel is necessary if the new industry is to maximize seed procurement without impinging upon other fisheries. Larval appearance is a relatively precise event in Maine, cued to early summer water temperature of 10–12 C and, apparently, full moon spawning events. Mussel larvae are more abundant on the flood tides indicating inshore and estuarine retention, although this retention relates to the morphometry and relative energy of the system. Webb Cove, a wide embayment with maximum sample station current velocity of 0.2 m/s, showed a random ebb tide vs. flood tide larval distribution; the narrow, long Damariscotta River estuary with 0.35 m/s current velocity showed a two‐fold flood tide larval enhancement and the Jordan River with 1.5 m/s current velocities showed up to a 14‐fold flood tide enhancement of mussel larvae and bysally drifting juveniles. Thus certain Maine estuaries may act as larval traps, providing areas of concentrated settlement and seed abundance. Primary setting normally begins with a large initial pulse in June followed by one or more secondary pulses throughout the summer. Secondary settlement (reattachment of bysally drifting juveniles) occurs at lower levels throughout the year, especially in late July and early August. Maximum attachment of larvae and juveniles occurs during periods of maximum current velocity. Extensive eelgrass beds at the mouths of some estuaries (i.e., Jordan River) may be the sites of extensive primary and secondary setting. Great Eastern Mussel Farms, the industry component, guided by these studies, is testing the deployment of live and shell mussel cultch to develop and optimize a new seed procurement system.
Establishment of Tilapia Spawning Families Providing a Continuous Supply of Eggs for in vitro Fertilization
Authors: Phillips Peter C. , Kohler Christopher C.
Published: April 2007

Three hybrid tilapia (Oreochromis mossambicus ± O. niloticus) spawning families were established in three separate culture tanks to provide a continuous supply of fresh gametes. An ovulation event, resulting in a natural spawn, an artificial spawn or oocyte resorption, occurred with a mean of every 1.4 days among 19 females, though only a few females demonstrated periods of evenly spaced 10 to 20 day maturation‐ovulation cycles. Ovulation events/female/year were similar among the three spawning families: 13.1, 17.5 and 13.4/female, as were mean interovulation intervals (23.6, 21.9, and 23.9 days). Estimated fertilization rates, both natural and as a result of strip‐spawning, were highly variable. Rates from natural spawns ranged from a mean per female of 25.7 to 57.3%, and from artificial spawns from 47.8 to 58.8%. Establishment and active management of spawning families of tilapias proved to be an effective procedure for obtaining a continuous supply of gametes for manipulative genetic research.
A Partial Energy Budget for the Australian Crayfish Cherax tenuimanus
Authors: Villarreal Humberto
Published: April 2007

The freshwater crayfish Cherax tenuimanus (marron) has been attracting an increasing degree of attention for aquaculture due to its high growth rate and large harvest size. In this study some important parameters related to the physiological energetics of C. tenuimanus were defined in a series of independent experiments.

Food consumption by marron increased when fed a variety of foods, providing up to 29 joule/g dry wt crayfish per hour. Mean energy content of feces was 7, 941 joule/g dry wt representing up to 17% of ingested food while excreted energy was not important in the overall budget. Metabolic requirements per hour were 5.4 joule/g dry wt. Gross conversion efficiency was up to 58% for the experimental diets. This ability gives the species a marked advantage for commercial culture over other related species with more subdued growth efficiencies.
A Standard Reference Diet for Crustacean Nutrition Research VI. Response of Postlarval Stages of the Caribbean King Crab Mithrax spinosissimus and the Spiny Lobster Panulirus argus
Authors: Lellis William A.
Published: April 2007

Two experiments were conducted to determine if two proposed crustacean reference diets, BML 81S or HFX CRD‐84, could serve as nutritional standards for early postlarval stages of the Caribbean king crab Mithrax spinosissimus or the spiny lobster Panulirus argus. In the first study, after an eight week trial period, survival of postlarval crabs (initial mean weight = 20 mg) was higher (P < 0.05) for crabs fed a control diet of commercial larval fish feed (66.7%) or BML‐81S (45.8%) than for crabs fed HFX CRD‐84 (16.7%). Final mean weight was also greater (P < 0.05) for crabs consuming the fry feed than for crabs fed BML‐81S or HFX CRD‐84 (710 vs. 460 and 340 mg, respectively). In the second study, after a ten week trial period, survival of second stage postlarval spiny lobsters (initial mean weight = 0.20 g) was greater (P < 0.05) for animals fed live adult Artemia (93.3%) than for lobsters fed HFX CRD‐84 (26.7%) or BML‐8lS (0%). Lobsters offered the casein‐based BML‐81S did not consume the feed and died within 25 days. Results suggest that BML‐81S may be an acceptable reference diet for Mithrax spinosissimus, but that neither BML‐81S nor HFX CRD‐84 is adequate for the early postlarval stages of Panulirus argus.
Mineral Requirements of Penaeus vannamei: A Preliminary Examination of the Dietary Essentiality for Thirteen Minerals
Authors: Davis D. Allen , Lawrence Addison L. , Gatlin Delbert M.
Published: April 2007

Diets containing a complete mineral premix or mineral premixes from which Ca, P, Na, CI, K, Mg, Mn, Fe, Zn, Cu, I, Se, or Cr were individually deleted were fed to juvenile Penaeus vunnamei (mean initial weight 79.5 mg) over a 4‐week experimental period. Final mean percent weight gain ranged from 1,472 (Cu‐free mineral premix) to 1,991% (Na‐free mineral premix) with an average of 1,812% for all treatments. Survival during the first two week period and the second two week period was greater than 92% and 88%, respectively. There were no significant differences observed among treatments for growth and survival data.

Upon termination of the growth trial, the hepatopancreas and carapace were dissected from the shrimp and evaluated for ash, Ca, P, Na, K, Mg, Mn, Fe, Zn and Cu content. Of the minerals analyzed, the individual deletion of Mg, Mn, Fe, Zn and Cu from the mineral supplement resulted in reduced tissue mineralization in P. vannamei whereas, the deletion of Ca and P from the mineral mix did not produce significant responses. Deletion of Se from the mineral premix resulted in a significant increase in the ash content of the carapace. Based on the information provided by this and other studies, further investigation of the dietary requirements of P. vannamei for Ca, P, Fe, Mg, Mn, Zn, Cu and Se is recommended.