bluuebunny/crossref_metadata_2025 huggingface dataset:
IN VITRO STUDIES TO CONTROL THE GROWTH OF MICROORGANISMS OF SPOILAGE AND SAFETY CONCERN IN HIGH‐MOISTURE, HIGH‐pH BAKERY PRODUCTS
Authors: KOUKOUTSIS JOHN , SMITH JAMES P. , DAIFAS DAPHNE PHILLIPS , YAYALAN VAROUJAN , CAYOUETTE BERNARD , NGADI MICHAEL , EL‐KHOURY WASSIM
Published: April 2007

Initial agar plate studies were done to determine the effects of various levels (0 to 2,000 ppm) of potassium sorbate (KS) and sorbic hydroxamic acid (SHA) over a wide pH range (5 to 9) on the growth of microorganisms of spoilage and safety concern in high‐moisture, high‐pH bakery products. While growth of most microorganisms was inhibited for > 28 days on agar plates containing ∼1,000 ppm of KS at pH 5 and incubated at 30C, growth of all microorganisms occurred in plates at pH 7 and 9, regardless of the concentration of KS. SHA was equally effective at pH 5, however, it proved to be a more effective inhibitor against most microorganisms at higher pH (9).

Subsequent agar plate studies were done with water‐ethanol (WE) and mastic oil‐ethanol (ME) emitters. While WE emitters failed to control the growth of all microorganisms under investigation, ME emitters controlled the growth of most microorganisms, with the exception of Listeria monocytogenes, for ∼12 to 28 days on agar plates packaged in high‐gas‐barrier Cryovac or metallized bags, respectively. Inhibition was not simply due to the levels of ethanol, which ranged from ∼1.2 to 2.8% v/v, but rather, the mastic volatiles in the package headspace.

This study has demonstrated the potential of SHA and ME emitters to control the growth of several microorganisms of spoilage and safety concern in high‐moisture, high‐pH bakery products. However, the type of packaging material influenced the antimicrobial efficacy of this vapor‐phase inhibitor.
Survival and Growth of Crangon nigricauda Larvae (Decapoda, Caridea) Raised on Experimental Diets
Authors: Villamar Daniel F. , Brusca Gary J.
Published: April 2007

Newly hatched Crangon zoeae from different maternal shrimp were raised separately using an Imhoff cone larval‐rearing system. Experimental diets were Chaetoceros gracile, live Artemia nauplii, lyophilized Arremia nauplii particles, calcium alginate microencapsulated (CAM) Artemia nauplii, lyophilized Daphnia magna and CAM Daphnia magna. A dependable “atomizer” design for lab oratory preparation of CAM diets was developed. Initially, survival rates of zoeae fed either Chaetoceros or live Artemia nauplii were evaluated in order to establish a suitable control diet for subsequent growth experiments, and the interbrood and intrabrood components of zoed survival variation were analyzed.

Crangon zoeae ate every type of food offered to them, but only Chaeroceros‐fed zoeae survived to metamorphosis. Zoeal survival rates were extremely variable. Interbrood variation was greater than intrabrood variation, but the difference was not statistically significant. Zoeae from smaller maternal shrimp were generally more active and had greater survival rates than zoeae from larger, presumably older and senescent shrimp. Zoeae that were fed Chaetoceros supplemented with CAM Artemia nauplii had significantly greater (P < 0.001) growth rates than siblings fed only Chaetoceros.

Suspension feeding on Chaetoceros was probably more efficient than raptorial feeding on Artemia nauplii, resulting in greater survival rates. Supplementing a successful microalgal diet with CAM Artemia nauplii allowed greater use of zoeal feeding mechanisms, added an animal nutrient source to the diet, and affected growth rates by increasing the molt increment and decreasing the intermolt period.
Substitution of Soybean Meal with Cottonseed Meal in Pond Feeds for Channel Catfish Reared at Low Densities
Authors: Robinson Edwin H. , Daniels William H.
Published: April 2007

Cottonseed meals were evaluted as partial and complete replacements for soybean meal in pond feeds for channel catfish grown at densities of 5,300/ha. The following dietary treatments were used: 1) glanded cottonseed meal (GC) in which ½ of the soybean meal was replaced; 2) glandless cottonseed meal (GLC) in which all of the soybean was replaced, 3) a control feed (C) typical of commercial catfish feeds. The feeding trial was conducted in 0.04 ha earthen ponds for a period of 176 days. Natural prey species were present in all ponds. Final weights and condition factors of fish fed the GC feed were reduced compared to those fed the GLC or C feeds. This response did not appear to be related to dietary gossypol levels. Even though the GLC feed appeared to be deficient in available lysine, final weight and feed conversion of fish fed the GLC feed were equal to those fed the C feed. Possible nutrient contributions of natural food available in the ponds could not be determined. There were no significant differences in feed conversions or dressout percentages of fish regardless of dietary treatment. Fish fed the GLC feed exhibited a higher percentage of fat and lower percentages of moisture, protein and ash (dry weight basis) in edible tissue than fish fed the other feeds. Free gossypol levels in edible fish tissue were below 100 ppm.
Optimal Product Mix for Integrated Livestock‐Fish Culture Systems on Limited Resource Farms
Authors: Engle Carole R.
Published: April 2007

A mixed integer linear programming model was developed to select constrained optimum combinations of aquacultural production alternatives for limited‐resource farmers. The model maximized production of fish and livestock for home consumption and cash income.

Poor farmers without access to credit sources make best use of pond resources by stocking fish and utilizing inorganic fertilizer. Integrated systems require greater levels of capital to cover livestock feed costs. Ponds that cannot be drained are best utilized by stocking a polyculture system of bighead carp (Aristichthys nobilis), common carp (Cyprinus carpio) and fathead minnows (Pimephales pro‐melas) while drainable ponds are more efficiently utilized in tilapia production.
Acclimation of Channel Catfish to Environmental Nitrite
Authors: Urrutia Michael L. , Tomasso J. R.
Published: April 2007

Empirical indications that channel catfish (Ictalurus punctatus) may acclimate to environmental nitrite were studied in the laboratory. Channel catfish were exposed to 1.31, 2.49, 4.42 or 6.30 mg/L nitrite‐N for 15 days. Methemoglobin concentrations in test fish indicated acclimation occurred in the fish exposed to 2.49 and 4.42 mg/L nitrite‐N. Acclimation was not observed in fish exposed to the highest or the lowest concentration of nitrite. Fish exposed to 6.30 mg/L nitrite‐N also developed anemia. The results indicate that channel catfish do have the ability to acclimate to nitrite and that this acclimation is concentration and time dependent.
Molting, Mortality, and the Effects of Density in a Soft‐Shell Crawfish Culture System 1
Authors: Culley Dudley D. , Duobinis‐Gray Leon
Published: April 2007

The molting and mortality patterns at a crawfish density recommended for commercial‐scale soft‐shell crawfish culture systems showed that, over a 116 day period, 74% of the crawfish molted, 22% died, and 4% remained in the system at the end of the study. Approximately three weeks of adaption to the system were required before molting rates of the crawfish began to increase. By the sixth week, the number of malted crawfish per day exceeded the overall mean and remained at this level until 10 days before moltable crawfish were depleted. In a second study, three density levels (3.7,4.9, and 6.1 kg crawfish/m2) were tested for 60 days. The lowest density produced significantly fewer (P < 0.05) molted crawfish. Mortality was significantly greater (P < 0.05) at the highest density compared with the lowest density. The highest density (6.1 kg crawfish/m2) showed a higher molting rate than the lower densities, but it was not significantly different (P < 0.05) from the molting rate of 4.9 kg/m2.
Diet and Food Assimilation by Channel Catfish and Malaysian Prawns in Polyculture as Determined by Stomach Content Analysis and Stable Carbon Isotope Ratios 1
Authors: Lilyestrom Craig G. , Romaire Robert P. , Aharon Paul
Published: April 2007

Stable carbon isotope ratios (∂3C) and stomach contents were used to determine the diet of channel catfish (Ictalurus punctatus) and freshwater Malaysian prawns (Macrobrachium rosen‐bergii) in polyculture. Catfish stomach contents were dominated by formulated rations. Macrophyte fragments and catfish ration were predominate in prawn stomachs. Catfish ∂13C ratios became lighter from June to October, which paralleled the change in ∂13C ratio of the formulated feeds fed to the fish. Prawn ∂13C ratios became heavier from June to October with a change in diet from seston to aquatic macrophytes and formulated catfish feed. Formulated feeds contributed 68‐99% of catfish growth, and “natural” pond biota, principally insects, the remainder. Prawns depended to a greater extent on the autotrophic food web for their diet. Seston and macrophytes contributed 18‐75% of prawn growth, and formulated feeds the remainder. The prawns fed on seston at small sizes (<7 g) and consumed more aquatic macrophytes and formulated catfish ration at larger sizes (<7 g).
Use of Mg‐L‐Ascorbyl‐2‐Phosphate as a Vitamin C Source in Shrimp Diets
Authors: Shigueno Kunihiko , Itoh Shinobu
Published: April 2007

To overcome the lability of vitamin C (L‐ascorbic acid or L‐AsA), an essential nutrient of shrimp diets, the efficacy of Mg‐L‐ascorbyl‐2‐phosphate (MAP), a relatively stable derivative of L‐AsA, was examined.

Groups of juvenile Penaeus japonicus were fed five different test diets containing different amounts of MAP for 100 days, to determine if MAP could be utilized by shrimp. Normal growth was observed on test groups fed diets containing 1,078, 430 and 215 mg MAP per kg, whereas mass mortality occurred in populations fed diets containing 43 and 0 mg MAP per kg. The dead shrimp found in the latter two treatments exhibited blackened lesions underneath the exoskeleton. The symptom looked similar to what was reported in previous papers as L‐AsA deficiency syndrome. The feeding experiment suggests that MAP can be utilized by P.japonicus as a suitable replacement for L‐AsA, and a supplement of 215 to 430 mg in 1 kg is sufficient to prevent clinical signs of vitamin C deficiency.

Repeated measurements of remaining L‐AsA and MAP, made after diet processing and storage, demonstrated that MAP was significantly more stable than L‐AsA and was less prone to leaching in sea water.
Sex‐Reversal of Oreochromis aureus by Immersion in Mibolerone, a Synthetic Steroid1
Authors: Torrans Les , Meriwether Frank , Lowell Fran , Wyatt Bill , Gwinup Paul D.
Published: April 2007

Mibolerone (MI), a synthetic steroid, was used to sex‐reverse undifferentiated Oreochromis aureus fry. Fry were exposed to 0.0, 0.3, 0.6, or 1.0 ppm MI in static‐water solutions for five weeks (immersion treatments) or were fed a diet containing 1.0 ppm MI for four weeks in a flow‐through system. Following hormone treatment, the fish were grown to over 60 mm total length prior to sex determination using gonadal squash examination.

Fish immersed in 1.0, 0.6, or 0.3 ppm MI had average tissue MI concentrations of 14.4, 5.6, and 3.3 ppm, respectively. Immersion in either 1.0 or 0.6 ppm MI for five weeks resulted in an average of 82% males and 18% ovo‐testicular fish (inter‐sex fish) with no gonadal females being produced. Exposure to 0.3 ppm MI resulted in 78.7% males, 20.7% ovo‐testicular fish, and 0.7% gonadal females. Feeding a diet containing 1.0 ppm MI resulted in 85% males, 11% ovo‐testicular fish, and 4% gonadal females. Fry growth and survival were negatively correlated with the MI concentration of the immersion treatments.

Exposing tilapia fry to static‐water solutions of 0.6 ppm MI for five weeks appears to be a feasible method of eliminating the production of functional females. Immersion solutions should be changed at least weekly to maintain an effective hormone concentration.
An Estimate of the Dietary Lysine Requirement of Juvenile Red Drum Sciaenops ocellatus
Authors: Brown Paul B. , Davis D. Allen , Robinson Ed H.
Published: April 2007

Quadruplicate groups of juvenile red drum (initial mean weight 2.7 g; 20 fish per replicate) were fed experimental diets containing 35% crude protein and graded levels of lysine for eight weeks. Lysine concentration in the basal diet was 1.2% and was supplied by a combination of peanut meal and shrimp‐head meal. The basal diet was supplemented with lysine‐HCI to provide 1.6, 2.0, and 2.4% lysine. Each of these diets contained an essential amino acid (EAA) premix. Two additional diets were formulated to contain 1.2 and 2.4% lysine without the EAA premix. Weight gain and feed efficiency (FE) data indicated between 1.2 and 1.6% dietary lysine was adequate. However, serum lysine concentrations indicated 1.6–2.0% lysine was required. Fish fed 1.2 or 2.4% lysine, without the EAA premix, exhibited reduced weight gain and feed efficiency. Results indicated that red drum were able to utilize crystalline amino acids when incorporated into diets containing intact protein and, when lysine was adequate, the proteins were deficient in at least one other essential amino acid. It is recommended that a dietary lysine level of 5.7% of the dietary protein be used in formulating red drum diets.
Sex‐Reversal of Oreochromis aureus by Immersion in Mibolerone, a Synthetic Steroid 1
Authors: Torrans Les , Meriwether Frank , Lowell Fran , Wyatt Bill , Gwinup Paul D.
Published: April 2007

Mibolerone (MI), a synthetic steroid, was used to sex‐reverse undifferentiated Oreochromis aureus fry. Fry were exposed to 0.0, 0.3, 0.6, or 1.0 ppm MI in static‐water solutions for five weeks (immersion treatments) or were fed a diet containing 1.0 ppm MI for four weeks in a flow‐through system. Following hormone treatment, the fish were grown to over 60 mm total length prior to sex determination using gonadal squash examination.

Fish immersed in 1.0, 0.6, or 0.3 ppm MI had average tissue MI concentrations of 14.4, 5.6, and 3.3 ppm, respectively. Immersion in either 1.0 or 0.6 ppm MI for five weeks resulted in an average of 82% males and 18% ovo‐testicular fish (inter‐sex fish) with no gonadal females being produced. Exposure to 0.3 ppm MI resulted in 78.7% males, 20.7% ovo‐testicular fish, and 0.7% gonadal females. Feeding a diet containing 1.0 ppm MI resulted in 85% males, 11% ovo‐testicular fish, and 4% gonadal females. Fry growth and survival were negatively correlated with the MI concentration of the immersion treatments.

Exposing tilapia fry to static‐water solutions of 0.6 ppm MI for five weeks appears to be a feasible method of eliminating the production of functional females. Immersion solutions should be changed at least weekly to maintain an effective hormone concentration.
Chemical Budgets for Polyethylene‐lined, Brackishwater Ponds
Authors: Daniels Harry V. , Boyd Claude E.
Published: April 2007

Budgets for water, nitrogen, phosphorus, chemical oxygen demand (COD), and dissolved oxygen (DO) were estimated from May to October 1986 in three 0.09 ha ponds stocked with striped bass Morone saxatilis (Walbaum). Ponds were lined with highdensity polyethylene sheeting to prevent seepage. Pond bottoms, except for side slopes, were covered with soil. Total rainfall roughly equalled evaporation. Liner runoff augmented rainfall inflow by 43%. The largest source of nitrogen input was feed ‐88% of the measured input. Overflow was the greatest measured loss of nitrogen. Denitrification and ammonia volatilization apparently removed large amounts of nitrogen. Feed applications and runoff were the major phosphorus inputs. Fish harvest and uptake by mud represented the major losses of phosphorus. The production of each kilogram of fish required 2.09kg of feed and released to the water, as metabolic waste, 118.55g nitrogen, 1.2g phosphorus, and 1.67kg COD. Metabolic wastes from fish resulted in the production of an additional 3.71kg of COD in phytoplankton and benthic algae. Thus, 1kg of live striped bass resulted in a total of 5.38kg of COD. Benthic respiration exceeded respiration of microorganisms in the water column. Total respiration exceeded oxygen produced by photosynthesis, but diffusion of oxygen from the atmosphere into the ponds was sufficient to maintain adequate DO concentrations for fish survival.
A Standard Reference Diet for Crustacean Nutrition Research.: III. Effects on Weight Gain and Amino Acid Composition of Whole Body and Tail Muscle of Juvenile Prawns Macrobrachium rosenbergii1
Authors: Reed Laurieann , D'Abramo Louis R.
Published: April 2007

Two proposed standard reference diets for use in studies of crustacean nutrition were evaluated using newly metamorphosed postlarvae of the fresh water prawn Macrobrachium rosenbergii, After 90 days, no significant differences in mean whole wet weight or time interval between successive molts of the two dietary treatment group existed. The dietary amino acid composition of each diet and the corresponding amino acid composition of either the whole body or tail muscle tissue were highly correlated. There was a poor correlation between the dietary amino acid composition and the free amino acid composition of whole body and tail muscle tissue. Both diets could adequately serve as reference diets for nutritional studies with juvenile M. rosenbergii.
Plasma Chemistries of Nitrite Stressed Atlantic Salmon Salmo salar
Authors: Bowser Paul R. , Wooster Gregory A. , Aluisio Anita L. , Blue Julia T.
Published: April 2007

Plasma chemistries were measured in Atlantic salmon (Salmo salar) exposed to elevated nitrite concentrations in an attempt to identify those parameters of potential value as early predictors of nitrite stress in a water‐reuse system. The most notable finding was a decrease in alkaline phosphatase (ALP) activity with increasing time of exposure to elevated nitrite concentrations. Chloride was found to have a protective effect against nitrite toxicity as indicated by higher ALP activities and lower percent methemoglobin in fish exposed to elevated nitrite concentrations at the higher of two chloride concentrations.
Evaluation of Semipurified Test Diets for Tilapia zillii Fingerlings
Authors: El‐Sayed Abdel‐Fattah M.
Published: April 2007

An experiment was conducted to evaluate semipurified test diets for Tilapia zillii fingerlings. Four isocaloric (300 kcal dietary energy/100 g) diets containing casein (at 30 and 39%). casein supplemented with L‐arginine (Arg) and casein/gelatin mixture as protein sources were fed to triplicate groups of T. zillii fingerlings at a daily rate of 3% of their body weight for 6 weeks. When casein was fed as the sole dietary protein source at 30% level, fish growth, feed conversion efficiency (FC) and protein efficiency ratio (PER) were significantly reduced. Those variables were significantly improved when casein was supplemented with Arg. The group of fish fed casein/gelatin diet showed the best growth and feed utilization. When casein was increased to 39% to meet the Arg requirement, fish growth and feed conversion were not significantly different from those of fish fed casein/gelatin diet, while PER and protein production value (PPV) were significantly reduced. These results indicated that casein/gelatin is superior to casein or casein/Arg as a protein source in semipurified test diets for T. zillii fingerlings.
Nutrient Concentrations of Catfish Feces and Practical Diets After Immersion in Water
Authors: Brow Paul B. , Robinson Edwin H. , Finne Gunnar
Published: April 2007

A study was conducted to quantify changes in the proximate components of fish feces and feeds when immersed in water for varying time periods. Catfish feces, a floating catfish diet, and a sinking trout diet were immersed for 5, 10, 20, 40, or 80 minutes. Dry matter losses were noted for all samples after immersion in water. There was a disproportionate loss of crude protein, ash, and nitrogen free extract (NFE) from the catfish fecal samples, ash and ether extract from the floating catfish feed, and NFE from the sinking trout feed. The losses noted would change crude protein, ether extract, NFE, and energy digestion coefficients by less than 7%, but ash and crude fiber digestion coefficients could change by as much as 23 and 35%, respectively. The ash concentration of unimmersed catfish feces indicated that this component may be a reliable indicator of nutrient digestibility in catfish.
An Ecological Foodniche Concept as a Proxy for Fish‐Pond Stocking Rates in Integrated Aquacultural Farming for Malaysia
Authors: Clonts Howard A. , Jolly Curtis M. , Alsagoff Syed Abdulkadir L.
Published: April 2007

The merits of integrated aquaculture farming (IAF) as a strategy for bolstering income for the rural poor have been recognized, but the economic efficiency and sustainability are yet to be determined. The effects of one species on another and the economic benefits, net of government support, have not been critically evaluated. The concept of a foodniche for alternative species in an aquatic environment has not been properly tested in an economic setting. Thus, this report reflects the results of applying the technique of mixed integer linear programming to determine the optimum combination of species within the context of a foodniche. The objective also included maximizing revenues, with minimal external input requirements, for a representative small Malaysian wet‐rice farm. It was found that the foodniche concept permitted flexibility in stocking rates, and that farmers could actually stock species at the exact rate that was optimal for profit, instead of standard fixed rates. Also, government subsidies for pond construction were essential for IAF success. The net revenues from IAF were low without interest‐free loans for pond construction.
The Use of Decapsulated Cysts of the Brine Shrimp Artemia as Direct Food for Carp Cyprinus carpio L. Larvae
Authors: Vanhaecke Paul , Vrieze Lieven De , Tackaert Wim , Sorgeloos Patrick
Published: April 2007

Decapsulated Arremia cysts have been evaluated as a direct food source for larvae of the carp Cyprinus carpio L. All decapsulated cyst diets gave excellent survival of carp larvae during the first two weeks of culturing. Unlike traditionally brine‐stored decapsulated cysts, dried Artemia embryos provided growth results comparable to those obtained with freshly hatched Artemia nauplii. Furthermore, except for Artemia embryos that lost their hatchability after long‐term storage in air, several other inactivation treatments, simulating improper harvesting and processing of cysts, did not produce a significant decrease in the nutritional quality of the decapsulated cysts.

Using decapsulated cysts 89 a direct food source for carp larvae, instead of nauplii, the quantity of cysts needed can be reduced by about 25% to 35% after one and two weeks of culturing, respectively. Moreover, the use of decapsulated cysts advances the possible commercialition of poor‐hatching and less expensive cyst products for culture of carp larvae.
Estimates of Additive Genetic Effects, Maternal Genetic Effects, Individual Heterosis, Maternal Heterosis, and Egg Cytoplasmic Effects for Growth in Tilapia nilotica
Authors: Tave Douglas , Smitherman R. Oneal , Jayaprakas V. , Kuhlers Daryl L.
Published: April 2007

Lengths and weights of Auburn University‐Egypt and Auburn University‐Ivory Coast strains of Tilapia nilotica and their F1 F2, and backcross hybrids were analyzed by multiple regression to estimate strain additive genetic effects, strain maternal genetic effects, individual heterosis (specific combining ability), maternal heterosis, and strain egg cytoplasmic effects for growth to determine why heterosis of the F2 and backcross hybrids was greater than that of the FI hybrids. Individual heterosis and maternal heterosis made the greatest contributions to growth. The F2 and backcross hybrids were larger than the F1 hybrids because of maternal heterosis. Regression coefficients were used to predict growth for any possible hybrid combination. Egypt ♀× Ivory Coast ♂ FI hybrid females backcrossed to Egypt males and Egypt ♀× Ivory Coast ♂ F2 hybrids were the largest groups evaluated in this study and were also predicted to have faster growth rates than any other possible Egypt‐Ivory Coast hybrid.
Intertidal Growth and Survival of Northern Quahogs Mercenaria mercenaria (Linnaeus 1758) and Atlantic Surf Clams Spisula solidissima (Dillwyn 1817) in Georgia
Authors: Walker Randal L. , Heffernan Peter B.
Published: April 2007

This work reports on the effects of intertidal planting heights upon the growth and survival of the northern quahog, Mereenaria mercenaria (L.) and the Atlantic sod clam, Spisula solidissima (Dillwyn), in the castal waters of Georgia. Quahogs (N = 100 per cage) at 19.5 mm in shell length were planted in replicate cages (N = 3) placed at the spring (SLW), mean (MLW), one (+1), two (+2), and three (+3) hours above mean low water mark. Surf clams (N = 200 per cage) at 41.5 mm in shell length were placed in replicate cages (N = 3) deployed, as above, in all sites except +3. Quahogs grown at the SLW mark after 15 months were significantly larger than clams planted at other tidal heights. Quahogs planted at the MLW mark were significantly greater in shell length than those planted at the +3, +2, and +1 marks. Clams at the upper three sites were not significantly different in size. An inverse relationship between clam growth and intertidal planting height was evident among surf clams. Surf clams grown at the SLW mark for six months were signplificmtly larger than those at the MLW mark which were larger than those grown at the +1 above MLW mark. No significant differences in quahog survival were detected between intertidal planting sites. There was no significant difference in surf clam survival between SLW (77.5%) and MLW (61%) marks, but there was significantly lower survival at the +1 mark (15%) and no survival at the +2 mark.
Enzymes Present in Pancreatic Extracts of the Dolphin Coryphaena hippurus
Authors: Divakaran S. , Ostorowski Anthony C.
Published: April 2007

Pancreatic extract of adult dolphin Coryphaena hippurus was found to have a broad range of proteolytic activity with two peaks, one at pH 5–6 and another at pH 10, when casein was used as a substrate. Enzymes similar in activity to those of pepsin, trypsin, amylase, lipase and collagenase were detected in the extracts by the use of specific chromogenic substrates for each enzyme. The relationship between these enzyme activities, and the formulation of diets for culture of this species, is discussed.
Maturation and Spawning of the White ShrimpPenaeus schmittiBurkenroad, 1936, Under Large Scale Rearing Conditions
Authors: de Siqueira Bueno Sérgio Luiz
Published: April 2007

This paper describes the reproductive performance ofPenueus schmittikept under controlled conditions in a maturation facility of a commercial shrimp farm. A total of 369 females and 368 males of wildP. schmittiwere used to form 9 broodstock groups. Unilateral ablation was performed on females only. Although females were not tagged, the total number of mated females (N =533) indicates that rematuration of the ovaries did occur. Only 9 mated females (1.69%) did not spawn and only 22 mated females (4.20%) of the remaining 524 cases did not produce viable spawns. These results indicate that a large number of viable spawns (94.18%) can be expected fromP. schmitti. A minimum latency period of 6 days for the ovaries to attain full development was observed twice. The highest mating frequency occurred between the 46th and 60th days after unilateral ablation, but mating frequency remained above 2% until the 90th day. The average number of nauplii/female/spawn was 78,961 (N =524) and the average fertilization rate of the eggs was 73.12% (N =297). Usually when the pair of the spermatophores is dislodged from the thelycum of the mated female, a small sperm mass still remains between the third pair of walking legs. This condition did not show any negative effect on the fertilization rate of the eggs and nauplii production. Mating behavior displayed byP. schmittiis also described and includes three distinctive phases: a) chasing, b) mating and c) post‐mating chase.
Clonidine Mects Growth Hormone and Growth in Juvenile Coho Salmon Oncorhynchus kisutch
Authors: Bates David J. , McKeown Brian A.
Published: April 2007

Growth hormone concentrations in juvenile cocho salmon were determined after intraperitoneal injections (yearlings; age 1+) and oral treatments (yearlings and fry; age 0+) with clonidine. Weights and lengths were also measured in coho juveniles fed diets supplemented with clonidine.

Plasma growth hormone concentration increased significantly (78.2%) 24 h after injection. Yearlings fed clonidine showed a significant increase (136%) in plasma growth hormone after 14 days, and levels remained elevated through 28 days (116%) before dropping to control levels at 42 days. Coho yearlings fed clonidine showed no significant increase in growth compared to controls after 56 days of treatment, but coho fry were significantly heavier (33%) and longer (8%) after 70 days.
Influence of 17‐α‐Methyltestosterone on Red Tilapia Under Two Thermal Regimes
Authors: Killian H. Steven , Kohler Christopher C.
Published: April 2007

Fingerling red tilapia (Oreochromis mossambicus±O. niloticus) were orally administered 17‐α‐methyltestosterone (MT) under a warmwater (27.0 ± 0.5 C) and coolwater (21.5 ± 0.5 C) thermal regime. In the warmwater experiment, fish received either 0, 1, 5, 10, 30, 60, or 100 mg MT/kg feed for 75 days. In the coolwater experiment, fish received 0, 10, or 60 mg MT/kg feed for 75 days followed by a 34 day withdrawal period. After 75 days, fish receiving 60 mg MT/kg feed (best treatment) in the warmwater and coolwater experiments exhibited significantly higher growth rates than controls by 35.3 and 45.8%, respectively. Likewise, feed conversion among groups receiving 60 mg MT/kg feed in the warmwater and coolwater experiments were significantly better than the controls (1.14 versus 1.30 and 1.44 versus 1.77, respectively). During the withdrawal period, no significant differences in growth rates or feed conversion were observed between the control and treatment groups. MT treatment significantly affected the body composition (whole body and empty carcass) of the red tilapia in both experiments, elevating percent moisture and protein values, but depressing percent fat values. Results demonstrated that incorporation of MT into fingerling diets offers potential for extending the period when tilapias actively feed and grow in temperate climates.
Maturing, Spawning and Egg Collecting of the White ShrimpPenaeus vannameiBoone in a Recirculating System
Authors: Chen Feng , Reid Bart , Arnold C. R.
Published: April 2007

A specially designed recirculating system was used to maintainP. vannameibroodstock for maturation, mating and spawning in the same tank. Two groups of different size shrimp were stocked in this system in Phase I (8 May to 5 September 1989) and Phase II (5 September to 5 December 1989). Results showed that this recirculating system was able to maintain good water quality keeping broodstock maturing, mating and spawning with high stocking density (10 shrimp/m2) and low mortality (6%). Seventy‐eight percent of spawned eggs were collected by a submerged egg collector. Mating success was very poor (3.4%) in Phase I even though there was normal spawning frequency. Mating success and nauplii production were much improved in Phase II. During Phase II 104 male and female broodstock housed in a 6 m3tank produced 1.6 ± 106nauplii (with 70% mating success) in three months. This study illustrated that broodstock size was a critical factor of successful mating and fertilization forP. vunnamei, and also, reduction of handling stress and lowered disturbance of the shrimp greatly enhanced the mating success.
Relative Susceptibility of Penaeus aztecus to Baculovirus penaei
Authors: LeBlanc Brian D. , Overstreet Robin M. , Lotz Jeffrey M.
Published: April 2007

Experimental infections of wild juvenile Penueus azrecus with Baculovinrs penuei (BP) demonstrate similar levels of prevalence as found in the natural environment. Moreover, neither postlarvae nor juveniles of P. setiferus, which rarely exhibit natural infections in the Gulf of Mexico, developed experimental patent infections using routine methods. Six other crustaceans, two of which were penaeids and none of which is a known host, did not develop experimental patent infections either.
Induced Spawning of Nassau Grouper Epinephelus striatus
Authors: Tucker John W. , Parsons J. Eugene , Ebanks Gina C. , Bush Phillippe G.
Published: April 2007

Nassau grouper Epinephelus striurus females ovulated 48–51 h after the first of two intramuscular injections of human chorionic gonadotropin given 24 h apart (usually 0.7 IU/gram body weight). Typical spawns contained 400,000–600,000 eggs. With fresh milt and clean water, fertilization rate was 85 and 86%. Survival from fertilization to first feeding for six spawns was 73–94%.
Incidence of Psorospermium sp. in Several Cultivated Populations of Crayfishes, Procambarus spp. (Decapoda, Cambaridae), in Southern Louisiana
Authors: Henttonen Paula , Lindqvist Ossi V. , Huner Jay V.
Published: April 2007

An organism tentatively classified as Psorospermium haeckeli was found in red swamp crayfish Procambarus clarkii at four culture sites in southwestern (3) and southeastern Louisiana (1) and in white river crayfish Procambarus zonangulus (=P. acutus acutus) at three culture sites in southwestern Louisiana. Incidence was about 70% in P. clarkii and 25% in P. zonangulus. Psorospermium haeckeli was present in all individual populations of P. clarkii sampled, but not in all P. zonangulus populations. Overall abundance was considerably lower than that observed in the European astacid crayfish Astacus astacus. Furthermore, the organism differed in shape, being longer and narrower than the organism found in A. astacus.
Economies of Pond Size for Hybrid Striped Bass Growout1
Authors: Gempesaw Conrado M. , Bacon J. Richard , Wirth Ferdinand F.
Published: April 2007

The objective of this study was to evaluate the relationship of pond size and hybrid striped bass growout profitability as an alternative source of farm income in the Mid‐Atlantic region. A dynamic, whole farm, Montdarlo capital budgeting simulation model (AQUASIM) and stochastic dominance with respect to a function technique were used to analyze the economics of hybrid striped bass growout from phase II to market production stage for eight farms categorized by pond sizes. Three scenarios are assumed to examine the effects of pond‐size dependent changes in feed conversion efficiency and fingerling survival rates on discounted after‐tax net present values and probabilities of economic survival and success. Optimal pond sizes were found to be in the 2.5 acre to 10 acre range.
Fatty Acid Composition of Unfed Cod Larvae Gadus morhua L. and Cod Larvae Feeding on Natural Plankton in Large Enclosures
Authors: van der Meeren Terje , Wilhelmsen Svein , Klungsosyr Jarle , Kvenseth Per Gunnar
Published: April 2007

Three different groups of cod larvae Gadus morhua L., feeding on natural plankton in two large enclosures, were analyzed for fatty acid composition through development. Unfed control groups and different size‐fractions of plankton were also analyzed. Consistency in changes of fatty acid composition suggests three developmental periods during early larval development. The periods corresponded with dietary shifts in the larvae, but a metabolic origin for changes in certain fatty acids was also evident. In the first period, relative amounts of n‐9 monounsaturates decreased, while n‐3 polyunsaturates together with certain fatty acids abundant in the small‐sized phytoplankton fraction increased. In the second and third periods, relative amounts of the longer n‐3 PUFA decreased, while fatty acids of calanoid copepod origin occurred in one group. The consistency in changes of larval fatty acid profiles in cod suggests development in both lipid absorption and lipid metabolism during ontogenesis.
Larviculture of the Greasy Grouper Epinephelus tauvina F. and the Brown‐Marbled Grouper E. fuscoguttatus F. in Singapore
Authors: Lim L. C.
Published: April 2007

This paper reports the larviculture of two grouper species, the greasy grouper Epinephelus tauvina and the brown‐marbled grouper E. fuscoguttatus, and examines the technical feasibility of breeding the fish. Fertilized eggs for larviculture were obtained by induced spawning through multiple hormonal injections of the female brooders, followed by artificial fertilization for the greasy grouper and by natural spawning in netcages for the brown‐marbled grouper.

For both species, larviculture was divided into three operational stages, i.e., stage 1 (day 0–12), stage 2 (from day 12 to day 24 for the greasy grouper and to day 30 for the brown‐marbled grouper) and stage 3 (day 24 or 30 to metamorphosis). Larvae were transferred to clean tanks after each stage. Total mortality around day 5–8 was common for the greasy grouper. Several modifications, including the feeding with super‐small strain rotifers, intensive feeding of rotifers with Nannochloropsis and the use of an oil‐skimmer, have been made to improve the situation. Two other major problems in larviculture were the high mortality observed after day 25 in the greasy grouper and the high cannibalism from day 35 onwards for the greasy grouper and from day 30 onwards for the brown‐marbled grouper. The shock syndrome exhibited by both species during the periods made culling of the fish impossible.

Based on the spawning and larval characteristics, brown‐marbled grouper is considered a better potential species for large scale fry production than the greasy grouper.
Economic Analysis of Japanese Household Demand for Salmon
Authors: Wessells Cathy Roheim , Wilen James E.
Published: April 2007

The recent glut of both wild and farmed salmon in world markets has forced producers to become aware of the need to expand their marketing efforts to ensure that demand is not outpaced by supply resulting in a further decline in prices. Japan has been a major market for wild salmon, particularly sockeye salmon from North America, since the introduction of the 200 mile Exclusive Economic Zone. As farmed supplies have continued to increase, exporters such as Norway and Chile have turned their attention to this market as well. Up until now, most of the farmed salmon exported to Japan has been targeted to the restaurant market. If exporters wish to expand their market in Japan, they may focus also on the retail market. Prior to any assessment of the potential of the retail market for fresh farmed salmon, it is useful to understand the role that salmon plays in Japanese household seafood consumption.

This paper examines household consumption patterns of salmon in Japan. An econometric model is presented which estimates household demand for fresh and salted salmon focusing specifically on the effects of seasonality, regional location, and prices of other seafood products. Two systems of demand equations, one for each of two regions of Japan, are specified and estimated using monthly data on prices and expenditures to capture the effects on household demand for 12 seafood products. Results indicate that seasonality plays a significant role in the demand for many seafood products, particularly fresh and salted salmon. In addition, these seasonal effects are not necessarily the same between regions of Japan. Salmon competes with different seafood products during different times of the year. A rich variety of factors should be considered when marketing fresh aquacultured salmon in the Japanese retail market.
A Practical Calcium Hardness Criterion for Channel Catfish Hatchery Water Supplies
Authors: Tucker Craig S. , Steeby James A.
Published: April 2007

Three pairs of brood channel catfish Ictalurus punctatus were induced to spawn in aquaria supplied with flowing water from a reservoir filled with ground water (calcium hardness = 110 mg/L as CaCO3= 44 mg/L as calcium). Fertilized egg masses were allowed to incubate in aquaria for 6 h and each mass was then split into five portions. The five portions were then allowed to hatch and the resulting sac fry developed in waters with calcium hardnesses of 0, 1, 5, 10, or 100 mg/L as CaCO3 (0, 0.4, 2, 4, or 40 mg/L as calcium). Test waters were prepared from distilleddeionized water and reagent‐grade chemicals; tests were conducted using static‐renewal conditions. Survival from hatch to onset of exogenous feeding (“swim‐up”) averaged 62% in calcium‐free water and 98% at all other calcium hardness levels. Wet weight gain, dry weight loss, and resistance to environmental hypoxia were significantly affected (P < 0.05) by environmental calcium levels: best growth, yolk utilization rate (indicated by changes in dry weight and visual observation), and tolerance to low dissolved oxygen concentrations were found at calcium hardnesses of 10 and 100 mg/L as CaCO3. Based upon these results, a minimum calcium hardness of 10 mg/L as CaCO3 (4 mg/L as calcium) is recommended for channel catfish hatchery water supplies.
Integrated Duck‐cum‐Fish Farming in Bangladesh
Authors: Latif Muhammad A. , Alam Mohammad J. , Rahman Mohammad A.
Published: April 2007

An experiment on integrated duck‐cum‐fish farming was conducted in 11 ponds of 0.1 ha each at the Fisheries Research Institute, Mymensingh, Bangladesh. Khaki Campbell layer ducks Anas platyrhychos were housed directly over the pond water surface at 200, 400 and 500 dncks/ha. Each density had three replicate ponds and two ponds had no ducks. Fish fingerlings were stocked at a total density of 8,850/ha. The species composition was silver carp Hypophthalmicthys molitrix 33.9%; catla Catla catla 12.4%; rohu Labeo rohita 18.1%; mrigal Cirrhina mrigala 28.8%. grass carp Ctenopharyngodon idella 1.4% and sor puti Puntius gonlonotus 5.4%. The fish were not given any supplemental feed, and the ponds were not fertilized except for the split duck feed and duck manure falling directly into the ponds. Ducks were fed with a feed formulated from locally available ingredients.

After one year the fish were harvested. The yield of fish increased with an increase in duck density. Highest net fish production of 4,250 kg/ha/yr was obtained from ponds with 500 ducks/ ha, compared to 490 kg/ha/yr from the control ponds. Manure of each duck contributed a net fish yield of 6.9–7.5/yr. Average egg production was 237 eggs per female duck per year. Economic analysis of the technology showed a net profit of about 100% of the total costs, indicating the economic viability of the technology.
Effects of Salinity on Hatching and Post‐Hatch Survival of the Australian Red Claw Crayfish Cherax quadricarinatus
Authors: Anson Kevin J. , Rouse David B.
Published: April 2007

Hatching rate and post‐hatch survival of Australian red claw crayfish Cherax quadricarinatus decreased with an increase in seawater salinity. An LC50 of approximately 11 g/L was determined for juvenile survival in seawater through 15 d. Sodium chloride salinity levels as low as 1 g/L killed all crayfish within 15 d. Tolerance of young red claw to higher levels of seawater salinity than sodium chloride salinity may he due to the concentration of other ions in seawater.
Significance of Habitat and Stock Re‐Testing for Enhancement of Natural Fisheries: Experimental Analyses with Queen Conch Strombus gigas
Authors: Stoner Allan W.
Published: April 2007

The queen conch Strombus gigas is a large, commercially important gastropod mollusc native to the Caribbean region that has become severely depleted because of overfishing and habitat destruction. Over the last 10 yr attempts have been made to rehabilitate conch stocks through releases of hatchery‐reared stocks, but successes have been few. Some of the reasons for high mortality in hatchery‐reared conch are elucidated by recent experiments conducted at Lee Stocking Island in the central Bahamas.

Field experiments with juvenile queen conch indicate that sites with similar depths, sediments, and macrophyte cover do not provide equivalent food and shelter for conch. Transplants of conch were successful only in sites known to be historically significant as nursery grounds. While small‐scale transplants can be used to screen potential outplant sites, only comprehensive understanding of the habitat requirements, behavior, feeding ecology, and predator‐prey relationships will lead to long‐term enhancement of fishery stocks. Differences in morphology, behavior, and habitat utilization between wild and hatchery‐reared stocks also had significant effects on the survivorship and growth of outplanted stock. Therefore, hatcheries must develop culture methods that do not reduce the natural fitness of wild stock. Successful enhancement of natural fisheries through outplanting of hatchery‐reared stocks depends upon: 1) development of hatchery animals sufficiently well adapted to survive in the field; and 2) release of the stock in suitable habitats at the optimal time. Close linkage between laboratory and field research, and hatchery operators will he necessary for the ultimate success of stock enhancement efforts.
Tissue Distribution of Enrofloxacin in Fingerling Rainbow Trout Oncorhynchus mykiss Following Different Doses of Oral Administration
Authors: Hsu Hui‐Min , Wooster Gregory A. , Bowser Paul R.
Published: April 2007

Rainbow trout Oncorhynchus mykiss were fed a ration medicated to provide enrofloxacin (Baytrilo®, Bayer) at 2.5, 5.0, or 10.0 mg drug per kg fish per d either 5 or 10 d. Tissue Concentrations of enrofloxacin were measured in liver, kidney, muscle, skin, and serum during the medication period, and thereafter for a total of 30 d. Highest tissue concentrations were observed in fish medicated with 5 mg enrofloxacin per kg fish per d for 10 d. Tissue concentrations of anitmicrobial activity were found to exceed minimum inhibitory concentrations of enrofloxacin for several isolates of Aeromonas salmonicida and Renibacterium salmoninarum. Lower than expected tissue concentrations were observed for the 10 mg per kg fish per d doses, perhaps due to a lack of acceptance of the medicated ration. The results support evaluation of a 5 mg per kg fish dose to treat bacterial infections of salmonids under field conditions.
Reproductive Performance of Penaeus stylirostris Females Injected with Heat‐Killed Vibrio alginolyticus
Authors: Pizarro F. , Alfaro Jorge
Published: April 2007

Good broodstock health is necessary for successful reproduction of captive penaeid shrimp. Diseases caused by opportunistic, gram‐negative bacterial pathogens (especially species of Vibrio) are a common problem in broodstock maturation systems worldwide. A variety of management practices, including frequent disinfection of the maturation system and use of antibiotics in water or feeds, have been used to reduce losses associated with vibriosis (Brock and LeaMaster 1992). Nevertheless, effective control of vibriosis remains an elusive goal. Failure of most management practices to control losses and controversy over the widespread use of antibiotics has stimulated interest in vaccination as a prophylactic measure to manage vibriosis in penaeid broodstock.
Spat Collection and Growth to Commercial Size of the Tehuelche Scallop Aequipecten tehuelchus (D'Orb.) in the San Matias Gulf, Patagonia, Argentina
Authors: Narvarte Maite A.
Published: April 2007

Studies on larval settlement and growth of the commercial scallop Aequipecten tehuelchus were carried out over a 2‐yr period in San Matias Gulf, Argentina. Gonadal index was used to indicate spawning and spat collectors were deployed when spawning began. Artificial spat collectors (mono‐filament bags filled with thin shrub branches) were placed at a depth of 25 m in two areas of the Gulf during two seasons (1989–1990 and 1991–1992). Maximum settlement occurred by mid‐February during the first season and by mid‐January in the second season. Larger numbers of spat were found in collectors placed near the sea bottom. After settlement, spat were removed and placed in cages for growout. Scallops reached the average commercial size (60 mm shell height) 16 mo later. Mortality rate during the entire period was 10%.