bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of the Trematode Bolbophorus confusus in Channel Catfish Ictalurus punctatus Ponds Using Salinity Manipulation and Polyculture with Black Carp Mylopharyngodon piceus
Authors: Venable Darrel L. , Gaudé Albert P. , Klerks Paul L.
Published: April 2007

This study evaluated the use of black carp Mylopharyngodon piceus and salinity manipulation for controlling the infection of channel catfish Ictalurus puncratus by a digenetic trematode (tentatively identified as Bolbophorus confusus). Control methods focussed mainly on the eradication of the intermediate snail host, the marsh rams‐horn Phanorbella trivolvis (previously referred to as Helisoma trivolvis), and were evaluated in laboratory tests and field experiments at a commercial catfish culture facility in southern Louisiana that was seriously impacted by the trematode. Introduction of fingerling black carp into catfish ponds at a density of 62 carpha resulted in an almost total elimination of P. trivolvis. The farm is now successfully using a facility‐wide stocking rate of 40 carp/ha. Laboratory experiments were conducted to investigate the effect of salinity manipulation using NaCl on free‐swimming trematode cercariae, the snail P. trivolvis, and catfish fingerlings infected with the cercariae. A salinity of 2.5 ppt had a detrimental effect on snail survival, growth, and reproduction. Salinity did not have a negative effect on the other two aspects of the trematode life cycle tested (in fact, survival of both cercariae and infected catfish fingerlings showed a positive dependence on NaCl over the 0–2.5 ppt range). A field‐experiment was then conducted in catfish ponds maintained at three salinities (2.5, 1.25, and 0.25 ppt) with rock salt, NaCl. Snail densities in ponds at 2.5 ppt salinity were consistently lower than in the other treatments and no trematode infection was noted among snails or catfish in the 2.5 ppt salinity ponds. Both the use of 2.5 ppt NaCl and black carp appear valuable management tools for controlling the digenetic trematode in caffish ponds.
Comparative Sensitivity of Yellowtail Seriolu quinqueradiata and Goldstriped Amberjack S. aureovittata to Photobacterium damsela subsp. piscicida
Authors: Kawakami Hidemasa , Yamashita Hirofumi , Sakai Masahiro
Published: April 2007

The pathogenicity of Photobacterium damsela subsp. piscicida to yellowtail Seriola quinqueradiata and goldstriped amberjack S. aureovittata was investigated. The 10‐d cumulative mortality of yellowtail and goldstriped amberjack challenged by 1.2 × 102 CFU/fish of P. damsela piscicida was 70% and 10%. respectively. Serum bactericidal activity of goldstriped amberjack was higher than that of yellowtail. Although the phagocytic activity against P. damsela piscicida was not observed in kidney leukocytes of yellowtail and goldstriped amberjack, the production of superoxide anion in goldstriped amberjack kidney leukocytes against P. damsela piscicida was higher than that of yellowtail.
Relative Abundance and Species Composition of Gram‐Negative, Aerobic Bacteria Associated with the Gut of Juvenile White Shrimp Litopenaeus vannamei Reared in Oligotrophic Well Water and Eutrophic Pond Water
Authors: Moss Shaun M. , LeaMaster Brad R. , Sweeney James N.
Published: April 2007

Gut bacteria may contribute significantly to the growth and survival of cultured shrimp, although little is known about factors that affect bacterial community structure in shrimp guts. The objective of this study was to determine the abundance and species composition of gut bacteria in juvenile white shrimp Litopenaeus vannamei reared in two different environments. Eight 120‐L tanks were stocked at a density of 8 shrimphank. Two treatments were tested for 10 d and consisted of tanks receiving flow‐through water from one of two sources: 1) well water pumped from a sea‐water aquifer (Well treatment), and 2) pond water pumped from an intensive shrimp pond (Pond treatment). Shrimp mid‐ and hindguts were excised on days 1, 3, 6, and 10 for enumeration of gram‐negative, aerobic bacteria by quantifying colony‐forming units (CFU) using standard microbiological plating techniques. Identification of bacterial isolates was made using the Biologa® GN Microplate system. Bacterial numbers were significantly greater (P > 0.05) in Well shrimp than in Pond shrimp on days 1 and 3. Following day 3, a decrease in bacterial numbers occurred in the Well shrimp, and no significant differences between treatments were observed on days 6 or 10. Guts from Well shrimp were dominated by Vibrio and Aero‐monas, and these two genera accounted for 80–851 of the bacteria on each sampling day. Guts from Pond shrimp exhibited a greater bacterial diversity and were dominated by Vibrio, Aeromonas, and Pseudomonas. Flavobacterium were identified in the guts of Pond shrimp on days 3 and 10, but were not identified in any of the Well shrimp. A greater understanding of gut bacteria‐shrimp interactions could lead to increased production and profitability for shrimp farmers through the development of more cost‐effective feeds and novel disease control strategies.
Production, Quality, and Low Temperature Incubation of Eggs of Atlantic Cod Gadus morhua and Haddock Melanogrammus aeglefinus in Captivity
Authors: Buckley Lawrence J. , Bradley Terence M. , Allen‐Guilmette Jennifer
Published: April 2007

Atlantic cod Gadus morhua and haddock Melanogrammus aeglefinus broodstock maintained under altered regimens of temperature and photoperiod spawned up to 8 mo per year. The cod broodstock produced viable embryos from October through June. The haddock broodstock produced viable embryos from December through May. Egg diameters were largest during the middle of the spawning season when water temperature was at a minimum, resulting in an inverse relationship between egg diameter and water temperature in both species. Egg quality was high, as evaluated by buoyancy, fertilization rate, regularity of early cleavage, and percent viable hatch. Low temperature incubation of cod and haddock eggs extended the embryonic period. Cod embryos tolerated a wider range of temperatures than haddock. High mortality (1 90%) was observed before hatching in haddock embryos incubated at 1 C. Atlantic cod embryos hatched at temperatures as low as —1 C, extending the embryonic period to 59 d. At 8 C Atlantic cod and haddock embryos hatched in 11–12 d. To determine if extending the embryo incubation time by using low temperatures had a detrimental effect, embryos were incubated through hatch at either 1 C or 6 C, and the larvae from both groups reared at 6 C. Growth and early survival of larvae were comparable in both treatments.
Low‐Temperature Tolerance of Southern Flounder Paralichthys lethostigma: Effect of Salinity
Authors: Taylor Winthrop E. , Tomasso Joseph R. , Kempton Christopher J. , Smith Theodore I. J.
Published: April 2007

Abstract.— Two studies were conducted to examine the influence of salinity on low‐temperature tolerance of southern flounder Paralichthys lethostigma. Juveniles (3.4 g ± 1.2 g in study one; 32.8 g ± 34.8 g in study two) were acclimated to 20 C at salinities of 1, S, 10, 20 and 30%o in study one and 1, 10 and 30%o in study two. Temperature was then decreased approximately 1 C per day to a nominal 4 C and 2 C, in studies one and two. respectively. Fish were subjected to the low temperatures for 10 d and then returned to the initial temperature (20 C) at a rate of approximately 1 C per day. Mortality ranged from 0 to 10% in study one and from 30 to 100% in study two and was significantly affected by salinity. Results of this research suggest that the chronic low‐level tolerance limit is between 2 and 4 C and that increased salinity offers some mitigating effect.
Physiological Responses of Rainbow Trout Oncorhynchus mykiss to Crowding and Anesthesia with AQUI‐S™
Authors: Davidson Glen W. , Davie Peter S. , Young Graham , Fowler Reece T.
Published: April 2007

Abstract.— Following exposure to the anesthetic AQUI‐S™, plasma cortisol concentration in immature rainbow trout was measured as (mean) 293 ± 48 ng/ mL, which was significantly (P > 0.05) higher than the mean concentration in resting fish. Cortisol concentrations remained significantly (P > 0.05) elevated for at least 24 h after treatment. This was accompanied by a significant increase and decrease in hematocrit and plasma potassium, respectively. These perturbations continued for at least 48 h following recovery from anesthesia. Plasma concentrations of total protein and sodium remained unchanged following anesthesia with AQUI‐S™. Crowding stress is commonly encountered by fish during manipulation in aquaculture situations. Anesthetising fish prior to, and during, manipulation may reduce the associated stress. Changes in cortisol values resulting from crowding (30 min; 0.1 kg/L) during anesthesia with AQUI‐S™ were not appreciably different from those in fish crowded without anesthesia. Thus, anesthesia with AQUI‐S™ at the recommended dose of 17 mg/L did not appear to be effective for alleviating the stress of crowding under the conditions of our experiments.
Vitamin C Requirements of the Angelfish Pterophylum scalare
Authors: Blom Jozef H. , Dabrowski Konrad , Ebeling James
Published: April 2007

Abstract.— Despite a large economical value of the ornamental fish trade, little information is available on the dietary ascorbic acid requirements of these species. Ascorbic acid requirements of fishes of the cichlid family appear to vary widely. Juvenile angelfish, a widely produced ornamental cichlid, were maintained on diets containing graded levels of ascorbyl monophosphate. Liver ascorbic acid concentrations after 96 d of feeding were significantly reduced in groups receiving 120 mg or less ascorbic acid equivalents/kg diet. However, no differences in growth or mortality between groups were found, and no external signs of ascorbic acid deficiency were observed, indicating a high resistance of this species against prolonged ascorbic acid deficiency. Based on the long possible life span of angelfish in the aquarium, we proposed a conservative dietary ascorbic acid requirement of 360 mg/ kg diet, necessary to maintain maximum tissue storage of this vitamin.
Changes in Hemocyte Counts in Litopenaeus stylirostris Subjected to Sublethal Infection and to Vaccination
Authors: Goarant Cyrille , Boglio Eric
Published: April 2007

Abstract.— A study was conducted with juvenile Litopenaeus stylirostris to evaluate the impact on total hemocyte counts of the injection of (1) formalin‐killed Vibrio penueicida cells (vaccine) and (2) a sublethal infection with a moderately pathogenic strain of Vibrio alginolyticus. After an initial decrease in hemocyte counts, both the vaccination and the sublethal infection induced higher hemocyte counts than controls. In order to investigate the possibility of increasing the number of circulating hemocytes in pond‐reared juvenile shrimp, the vaccine was added to the diet. No effect on the hemocyte counts was observed over a 20‐d feeding period.
Amino Acid Composition of Developing Larval Freshwater Prawn Macrobrachium rosenbergii
Authors: Roustaian Paymon , Kamarudin Mohd Salleh , Omar Hishamuddin , Saad Che Roos , Ahmad Mansor Haji
Published: April 2007

Abstract.— Amino acid profiles of freshwater prawn Macrobrachium rosenbergii were determined during early larval stages (I‐IX) to provide some baseline biochemical information of the growing larvae. The larvae obtained from several females were stocked into three 250‐L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii and egg custard containing 5% cod liver oil. For each developmental stage, larval samples from each experimental tank were pooled, freeze dried and after acid hydrolysis, the quantification of amino acids was done by a reverse phase high performance liquid chromatography (N= 2). The highest represented of the total amino acids were for glutamic acid and phenylalanine (with cystine) with ranges from 13.4–16.6 and 9.7–11.5%, respectively, whereas tryptophan (1.4–1.6%). methionine (1.4–2.7%) and histidine (2.9–4.2%) were relatively lower. The levels of the following essential amino acids did not significantly change during larval development: arginine, leucine, phenylalanine (plus cystine), threonine, tryptophan and valine. Despite statistically significant changes that were observed in levels of some amino acids, amino acid composition appeared to be relatively unchanged during the larval growth. The results may suggest that the amino acid requirements of the freshwater prawn is relatively constant during larval life and can be satistied by a suitable protein source that resembles the larval amino acid profile.
Application of Compensatory Growth to Enhance Production in Channel Catfish Ictalurus punctatus
Authors: Chatakondi Nagaraj G. , Yant Roger D.
Published: April 2007

Four treatment groups that received repeating cycles of fixed feed deprivation for either 0, 1, 2, or 3 d (control, treatment 1, treatment 2, and treatment 3, respectively), followed by periods of refeeding with a 36% protein commercial catfish feed once daily as long as the active phase of compensatory growth (CG) persisted, were assessed in flow‐through aquaria. No‐feed periods elicited the CG state and were immediately followed by days of ad libatum refeeding. At the end of 10 wk, average growth rate (AGR) of fish was higher (P < 0.05) than the control by 40%, 180%, and 191% for treatment 1, treatment 2, and treatment 3, respectively. The average weight of fish in treatment 3 was heavier (P < 0.05) than the average control group at the end of the study period. Mean daily feed consumption was 3.91%, 5.03%, 5.36%, and 5.98% for control, treatment 1, treatment 2, and treatment 3, respectively. Mean feed consumption per fish per day was 24%, 71.3%, and 70.7% higher than the control in treatment 1, treatment 2, and treatment 3, respectively. Restricted feeding is one of the effective methods to contain ESC‐related losses in commercial channel catfish fingerling operations. The mean cumulative survival of treatment groups registered higher (P < 0.05) survival to Edwardsiella ictaluri infection compared to the daily fed control fish. Results from this study show that compensatory growth response triggered by periodic non‐feeding days can improve growth rate, feed consumption, and improved survival to ESC infections in channel catfish fingerlings.
In Vivo Transfection of Adult Eastern Oysters Crassostrea virginica
Authors: Buchanan John T. , Cheng Ta Chi , Peyre Jerome F. La , Cooper Richard K. , Tiersch Terrence R.
Published: April 2007

The eastern oyster Crassostrea virginica provides a commercially valuable industry along the eastern and Gulf coasts of the United States. Recently this industry has been damaged by disease problems, creating an interest in the use of gene transfer (transfection) to improve disease resistance. We transfected adult oysters with two genes, red‐shifted green fluorescent protein (rsGFP), commonly used as a reporter gene, and the lytic peptide cecropin B (cepB), known to have antimicrobial properties. Oysters were transfected by injecting DNA mixed with SuperFect™ reagent (Qiagen Inc.) into the adductor muscle sinus. Oysters were assigned to three groups of 15: the first was injected with rsGFP complexed with transfecting reagent: the second was injected with cepB complexed with transfectlng reagent; and the third was injected with saline (control group). Hemolymph was collected at 4 and 10 d after injection. DNA was extracted for analysis by polymerase chain reaction (PCR), and hemocytes were examined by flow cytometry and fluorescence microscopy for detection of green fluorescence due to rsGFP expression. The rsGFP gene was detected by PCR in hemocytes from 14 of 15 oysters at day 4, and in 15 of 15 oysters at day 10. The cepB gene was detected by PCR in 12 of 15 oysters at day 4 and in 14 of 15 oysters at day 10. No oysters from the control group were positive for either gene at days 4 or 10. Green fluorescence was detected by flow cytometry at significantly higher levels (P < 0.05) in oysters injected with rsGFP than in other oysters at day 4, but not at day 10. This report indicates the ability to introduce DNA into adult eastern oysters with subsequent gene expression. Future work will involve developing these techniques for enhanced disease resistance in oysters.
Evaluation of Protein Quality in Microbound Starter Diets Made with Decapsulated Cysts of Artemia and Fishmeal for Fish Larvae
Authors: García‐Ortega Armando , Huisman E. A. , Sorgeloos Patrick , Verreth Johan
Published: April 2007

Abstract.— The protein quality of carboxymethylcellulose microbound diets (MBDs) made with decapsulated cysts of Artemia andlor fishmeal as protein sources was used as an indicator of their suitability as starter feed for fish larvae. Studies on the proximate, fatty acid and amino acid composition. in vitro protein digestibility. diet solubility, and protein structure were combined with an in vivo feeding experiment with African catfish Clarias gariepinus larvae to evaluate the protein quality of the MBDs and a commercial diet. The growth of catfish larvae was higher when fed Artemia‐based MBDs than with fishmeal‐based MBDs, despite the higher protein and amino acid content of the latter. The in vitro protein digestibility was high for all the MBDs in comparison to a commercial diet. Differences were found in the protein molecular weight among the diets. Most of the proteins in the fishmeal‐based diets had low molecular weight in the range between 7.4 and 49.2 kDa. The Artemia‐based MBDs had larger protein fractions between 29.4 and 82 kDa. Decapsulated cysts improved the utilization of the MBDs when used in combination with fishmeal. Besides the effect of chemical attractants, the explanation for the positive effect of Artemia has yet to be elucidated. However, attention should be given to interactions between nutrients (e.g., protein‐lipid) in live food, which might have an effect on the functional properties of food proteins.
Hemolymph Oxyhemocyanin and Protein Levels and Acid‐Base Balance in the Tiger Shrimp Penaeus monodon Exposed to Copper Sulfate
Authors: Lin Chia‐Hsin , Chen Jiann‐Chu
Published: April 2007

Abstract.— Subadult tiger shrimp Penaeus monodon (30.15 ± 2.19 g) were exposed individually in sea water of 25%o to 0 (control), 1.11, 4.76, 10.06 and 19.09 mg/L copper for 24 h. Hemolymph pH, PO2 (partial oxygen pressure), PCO2 (partial carbon dioxide pressure), HCO3, oxyhemocyanin and protein levels were determined. Hemolymph PO2 increased, whereas hemolymph pH, PCO2, HC03‐, oxyhemocyanin. protein and the ratio of oxyhemocyanidprotein levels decreased with increasing concentrations of ambient copper in the range of 1.11 to 19.09 ma/L. It is concluded that P. monodon following 24‐h exposure to ambient copper as low as 4.76 mg/L shows a reduction of oxyhemocyanin, protein, and the ratio of oxyhemocyanin to protein, and develops metabolic acidosis in the hemolymph.
Effect of Low Salinity on Growth and Survival of Postlarvae and Juvenile Litopenaeus vannamei
Authors: Laramore Susan , Laramore C. Rolland , Scarpa John
Published: April 2007

The effect of low salinity on survival and growth of the Pacific white shrimp Litopenaeus vannamei was examined in the laboratory due to the interest of raising shrimp inland at low salinities. In three separate experiments, individual L. vannamei postlarvae (∼ 0.1 g) were cultured at salinities of either 0.5, 1, 1.5, 2, or 3 ppt (N= 5 or 10/treatment) for 18 to 40 d at 30 C in individual 360‐mL containers. In each experiment controls of 0 and 30 ppt were run. There was no postlarval survival at salinities < 2 ppt. Survival was significantly different (P < 0.01) at 2 ppt (20%) compared to 30 ppt (80%). Growth was also significantly different (P < 0.01) at 2 and 3 ppt compared to 30 ppt (416%, 475%, and 670%, respectively). A fourth experiment compared juveniles (∼ 8 g) and postlarvae (∼ 0.05 and 0.35 g). Shrimp were cultured at salinities of 0, 2, 4, and 30 ppt for 40 d at 25 C, in individual 360‐mL and 6‐L containers (N= 7/treatment). There was no postlarval survival at < 2 ppt. Postlarval survival at 4 ppt (86%) was not significantly different (P > 0.05) from 30 ppt (100%). Juveniles exhibited better survival at lower salinities (100% at 2 ppt) than 0.05 and 0.35 g postlarvae (29% and 14% respectively, at 2 ppt). The effects of salinity on growth varied with sizdage. Final growth of 0.05 g postlarvae at 2 ppt (693%) was significantly less (P < 0.01) than at 4 ppt (1085%) and 30 ppt (1064%). Growth of 0.35 g postlarvae was significantly less (P < 0.01) for 4 ppt (175%) than for 30 ppt (264%). There was no growth data for juveniles (8 g). It appears from these experiments that the culture of L. vannamei poses risks when performed in salinities less than 2 ppt.
Comparisons of RNA/DNA Ratios, Growth, and Metabolism in Different Populations of Juvenile Turbot Scophthalmus maximus Reared at Four Temperatures
Authors: Imsland Albert K. , Foss Atle , Sveinsbø Bjørn , Jonassen Thor M. , Stefansson Sigurd O.
Published: April 2007

We compared RNA/DNA ratios, growth and routine oxygen consumption in populations of juvenile turbot from Norway, Scotland, and France reared at low (10 C), medium (14 C, 18 C) and high (22 C) temperatures. The relationships between growth and RNA/DNA ratios differed between temperatures, although they were always positive. Growth and RNA/DNA of the Norwegian fish were higher than those of the other populations especially at the two highest temperatures (18 C and 22 Q. Minor differences were found between the Scottish and French populations. Fish from the Norwegian population displayed the lowest oxygen consumption at these temperatures (146 and 270, 182 and 310, 192 and 328 mg O2/kg per d, for 18 and 22 C, and Norwegian, French, and Scottish populations, respectively). Growth differences did not conform to a simple thermal adaptation model, but might represent an example of countergradient variation in growth. The findings have implications for turbot culture, particularly in selection focusing on growth performance.
Performance of Juvenile Coho Salmon Oncorhynchus kisutch Fed Diets Containing Meals from Fish Wastes, Deboned Fish Wastes, or Skin‐and‐Bone By‐Product as the Protein Ingredient
Authors: Rathbone Cindra K. , Babbitt Jerry K. , Dong Faye M. , Hardy Ronald W.
Published: April 2007

The suitability of meals derived from fish processing wastes as the protein fraction in practical diets for hatchery‐reared coho salmon was investigated. The study compared the performance of coho salmon fed diets containing three products: a skin‐and‐bone meal (SB), a deboned meal (DM), and a whole‐fish meal (WM) made directly from the fish wastes. A commercial trout diet (CO) was fed to a fourth treatment group. Diets were fed at 3% of body weight per day to juvenile coho salmon for 12 wk. Survival (> 94%) was not significantly different among treatment groups. Average fish weight, feed conversion ratio, whole body proximate and mineral composition, and protein and phosphorus retention were compared. There were no significant differences after 12 wk of feeding in fish weight between WM, DM, and CO, but SB had significantly lower weight and whole body lipid, and significantly higher ash. Compared to WM, DM had a significantly lower feed conversion ratio and higher retention of protein and phosphorus, but these indices were not significantly different from CO. It is concluded that DM is a potentially superior protein ingredient compared to WM, while specific characteristics of SB will limit its use as a protein source in feeds for salmonids. However, SB may prove to be a suitable mineral supplement when added at a low level. Utilization of fish processing wastes in salmonid diets could be a commercially viable alternative to direct disposal of processing wastes.
Reproductive Performance of Macrobrachium rosenbergii Females in Captivity
Authors: Cavallo Ronaldo O. , Lavens Patrick , Sorgeloos Patrick
Published: April 2007

Abstract.— The breeding frequency, fecundity, egg hatchability, larval output and viability of pond‐reared, mature Macrobrachium rosenbergii females were individually followed up during 180 d. Sexually mature prawns were maintained under controlled laboratory conditions (28.7 C and 12‐h light/d) in a 190‐L freshwater recirculation system and fed a formulated diet. Ovarian development, moulting and spawning events were checked daily. At least six consecutive moults were recorded for each of the 18 females. The duration of the intermoult period averaged 27.5 d and was not affected by ovarian development or spawning, but intermoult periods followed by spawning had significantly lower growth rates. From a total of 126 moulting events recorded, egg laying successfully followed 76 (60.3%) of them. The number of eggs per spawn (NES) varied from 26,587 to 74,775 for females weighing 20.0 to 55.8 g. The relationship between NES and female size (W; in g) was found to be NES = 484 + 1454W (r2= 0.74). Results suggest that the number of viable larvae produced per egg clutch may be increased by in vitro incubation, as the losses of eggs, which usually occur under in vivo incubation, are prevented. The present study illustrates that under adequate and stable rearing conditions, M. rosenbergii females are able to spawn up to five times during 180 d, in comparison to three to five times per year as reported for wild prawn populations.
Survival and Growth of Walleye Stizostedion vitreum Fry as Affected by Water Recirculation, Feed Transition Age, and Stocking Density
Authors: Aneshansley Edward D. , Timmons Michael B. , Colesante Richard I
Published: April 2007

Abstract.— The effects of recirculation aquaculture on walleye Stizostedion vitreuin fry culture was evaluated from hatch (day 0) to day 65 and compared to traditional flow‐through aquaculture used at New York State's Fish Culture Station, Oneida, New York, USA. A comparison of survival rates of walleye fry through a feed transition period was also conducted with the variable being the age (d) at which dry feed was first introduced to fingerlings; this trial was conducted using recirculation aquaculture systems only. Comparisons were made of growth rates and survival rates broken down into two life stages: stage one was from day 0 to day 45 and stage two from day 45 to day 65. All systems were taken off live feed completely on day 45 resulting in a feed transition period between days 45 and 65. Fish in the flow‐through system had the highest cumulative growth rates through day 70 (P < 0.05) while fish in the recirculating system grew faster through day 53 (P < 0.10). The recirculating system showed significantly higher survival rates during the feed transition period (day 45–65) than fish in the conventional flow‐through system (P < 0.05). This is important because the transition period is the most stressful period in training fingerlings onto dry feed from a live diet. It was found that fish started on a dry diet on day I or day 14 in addition to the live diet had a significantly higher survival rate through the feed transition period than fish started on dry feed on day 30 (P < 0.1). The age at which dry feed was introduced had no significant impact on growth rates. There was a significant positive correlation (P < 0.05) between survival rates and the initial stocking density over a range of densities from 3,500 to 7,000 fish/m3.
Size Economies of a Pacific Threadfin Polydactylus sexfilis Hatchery in Hawaii
Authors: Kam Lotus E. , Leung PingSun , Ostrowski Anthony C. , Molnar Augustin
Published: April 2007

A spreadsheet model has been developed to determine the viable scale for a commercial Pacific threadfin Polydactylus sexfilis hatchery in Hawaii. The production scheme is modeled after current practices performed at the Oceanic Institute in Waimanalo, Hawaii. For a hatchery enterprise producing 1.2 million fry per year, the cost associated with raising one 40‐d‐old 1.00‐g fry is estimated at 22.01ø. The largest variable costs are in labor and supplies, which comprise 49% and 9% of the total production cost. The combined annualized fixed cost for development and equipment is approximately 12% of total production cost. At a sale price of 25ø per fry, the 20‐yr internal rate of return (IRR) is 30.63%. In comparison to the 22.01ø unit cost for 1.2 million fry production, analyses of smaller enterprises producing 900,000 and 600,000 fry per year reflected significant size diseconomies with unit costs of 27.41ø and 38.82ø, respectively. Demand to support a large scale Pacific threadfin commercial hatchery is uncertain. Since smaller scale commercial hatcheries may not be economically feasible, facilities may seek to outsource live feed production modules or pursue multiproduct and multiphase approaches to production. An analysis of the production period length, for example, indicates that the cost for producing a day‐25 0.05‐g fry is 17.25ø before tax and suggests the financial implications of transferring the responsibility of the nursery stage to grow‐out farmers. Evaluation of the benefits gained from changes in nursery length, however, must also consider changes in facility requirements, mortality, and shipping costs associated with transit, and the growout performance of and market demand for different size fry. Sensitivity analyses also indicate the potential cost savings associated with the elimination of rotifer, microalgae, and enriched artemia production. Managerial decisions, however, must also consider the quality and associated production efficiencies of substitutes.
Nutritional Properties of the Marine Rotifer Brachionus plicatilis Fed the Freshwater Microalgae Selenastrum capricornutum
Authors: King Joan M. , Liang Xiaoming , Rusch Kelly A.
Published: April 2007

This study examined the effects of storage time on the fatty acid composition of freshwater Selenastrum capricornutum algal paste under 4 C refrigeration, the fatty acid composition of rotifers fed the fresh and stored algal paste, and the toxicological properties of the algal paste. Microalgae were produced in a hydraulically integrated serial turbidostat algal reactor (HIS‐TAR), harvested as a paste, refrigerated and analyzed every 2 wk. Fresh Selenastrum capricornutum paste had almost three times greater concentration of unsaturated fatty acids than saturated fatty acids. Over 50% of the unsaturated fatty acids were made up of n‐3 and n‐6 fatty acids. Total unsaturated, n‐3 group and n‐6 group fatty acids decreased (P 0.05) during storage, including the nutritionally important fatty acids (C20:4n6, C20:5n3, C22: 6n3). Rotifers fed 2– and 4‐wk‐old algal paste had a significantly lower (P 0.05) total unsaturated fatty acid percentage and significantly greater (P 0.05) total saturated fatty acids than those fed fresh algae. There were no significant changes in the n‐6 group fatty acid level in the 4‐wk‐old paste feeding study or for the n‐3 or n‐6 groups in the 2‐wk‐old paste feeding study as compared to fresh algae. The levels of the three nutritionally important fatty acids (C20:4n6, C20:5n3, C22:6n3) did not differ between rotifers fed fresh and stored algae. Stored algae did not present toxicity to rotifers and Daphnia at the normal feeding concentration. These results indicated that the use of refrigerated freshwater algal paste for production of rotifers results in live feed with adequate nutritional properties for marine larviculture. This could eliminate the costs associated with production of marine algae, which could be replaced with freshwater algae, and may provide an alternative to cryopreservation.
Comparison of Various Animal Protein Sources for Growth, Feed Efficiency, and Body Composition of Juvenile Channel Catfish Ictalurus punctatus
Authors: Li Menghe H. , Manning Bruce B. , Robinson Edwin H.
Published: April 2007

A laboratory study was conducted to compare different animal protein sources in diets containing 32% protein for channel catfish Ictalurus punrtatus. The experimental diets were practical‐type diets and formulated to meet or exceed all known nutrient requirements for channel catfish. Twenty juvenile channel catfish (initial weight: 6.4 g/fish) were stocked into each of 25 110‐L flow‐through aquaria (five aquaria/treatment). Fish were fed twice daily to approximate satiation for 9 wk. Fish in each aquarium were counted and weighed collectively every 3 wk. No significant differences were observed in feed consumption, weight gain, feed efficiency, survival, percentages visceral fat and fillet yield, or proximate composition of fillets among channel catfish fed diets containing either 5% menhaden fish meal, meat and bone/blood meal, catfish by‐product meal, poultry by‐product meal, or hydrolyzed feather meal with supplemental lysine. The data indicate that these animal protein sources can be used interchangeably in diets for channel catfish without affecting fish growth, feed efficiency, or body composition.
Pharmacokinetics of Dietary 13C‐labeled Icosapentaenoic Acid in Japanese Flounder Paralichthys olivaceus
Authors: Tago Akio , Teshima Shin‐Ichi
Published: April 2007

The objectives of this study were to investigate: 1) the pharmacokinetics of dietary icosapentaenoic acid (EPA) in the plasma using 13C‐labeled EPA ([13C]EPA); 2) the bioavailability of [13C]EPA with different chemical forms; and 3) an effective plasma EPA level for normal growth of the Japanese flounder Parachthys olivaceus. [13C]EPA was biosynthesized using the Chlorella Nannochloropsis oculate, and 1‐myristoyl 2‐[13C]icosapentaenoyl phasphatidyl‐choline ([13C]EPA‐PC) and [13C]EPA ethyl ester ([13C]EPA‐EE) were chemically synthesized from [13C]EPA. Free [13C]EPA ([13C]EPA‐FREE) dissolved in 0.5% tragacanth gum‐polye‐thyleneglycol (3:1, V/V) was administered to the Japanese flounder at dosages of 2.8, 5.6, and 16.8 mg/kg by a single oral administration. [13C]EPA‐PC (44.8 mg/kg) and [13C]EPA‐EE (18.3 mg/kg), equimolar to 3.0 mg [13C]EPA‐FREE (16.8 mg/kg), were administered to the fish in a similar manner. In [13C]EPA‐FREE dosed fish, the kinetics of the mean plasma [13C]EPA were linear with respect to dose. [13C]EPA‐FREE and [13C]EPA‐PC were more efecient in maintaining high plasma EPA levels than [13C]EPA‐EE in the Japanese flounder. [13C]EPA was distributed in plasma, blood cell, eyeball containing the orbital fat, liver, stomach, intestine, skin, brain, heart and muscle in three [13C]EPA derivatives studies. The effective plasma EPA level for normal growth of the Japanese flounder is estimated to be 307 to 937 μg/mL for EPA‐FREE administration, and from 286 to 815 μg/mL 6.3 to 38 mg/mL for the EPA‐PC administration.
Temporal Growth Patterns of Farmed Juvenile Southern Bluefin Tuna, Thunnus maccoyii (Castelnau) Fed Moist Pellets
Authors: Glencross Brett D. , Clarke Steven M. , Buchanan Jeffery G. , Carter Chris G. , van Barneveld Robert J.
Published: April 2007

The growth, condition, and feed utilization patterns of juvenile southern bluefin tuna (SBT) fed moist‐pellets were examined over a 19‐wk period from March to July 1999. The SBT had significant weight gain over the course of the study, increasing on average from about 27 to 34 kg (dependent on size class). No significant weight gain by the SBT occurred in the first 5 wk of the study. Following this initial period of slow growth, the rate of weight gain increased, ranging between 40 to 90 g/d. Weight gain peaked after 11 wk, with no further gain occurring after this time point. Weight gain was strongly related to average daily feed intake (AFI) which was predominantly influenced by water temperature. Weight gain was minimal following the decrease of water temperatures below 15 C, consistent with a decrease in feed intake from peak values at the beginning of the study to basal levels by week 13. Basal feeding levels were maintained for the remainder of the study through to week 19. Although water temperature and AFI were strongly related, other time related effects also appeared to be signillcant. A relationship between condition index and feed intake was also identified. Condition index of the SBT increased from about 19 kg/m3 to 22 kg/m3 over the 19‐wk period. Similar to the patterns observed in growth, there was also an initial delay in increases of condition index. The results from this study support that the majority of weight gain by juvenile SBT occurs during the early part of the production season and that this is most likely influenced indirectly through responses to water temperature. The results of this study also suggest that there is little value in conducting growth trials beyond the point where water temperatures decrease below 15 C. Although there was minimal weight gain or improvement in condition beyond the 11‐wk time point, these parameters would need to be considered in conjunction with flesh quality characteristics to identify optimum harvesting regimes.
Potential Detection and Deterrence Ranges by Harbor Seals of Underwater Acoustic Harassment Devices (AHD) in the Bay of Fundy, Canada
Authors: Terhune J. M. , Hoover C. L. , Jacobs S. R.
Published: April 2007

Abstract.— Underwater acoustic harassment devices (AHDs) are designed to deter seals from attacking fin‐fish aquaculture cages. They may also be unintentionally disturbing non‐target marine mammals. As the distance from the sound source increases, the rate at which the sound pressure level (SPL) drops per unit distance decreases. This prohibits presenting loud sounds near the cages without also creating sounds that can be detected kilometers away. In situ measurements of the sound fields of two AHDs in the Bay of Fundy, Canada, were made. The distances at which a loud AHD with short duration pulses (1.8 msec, 195 dB re 1 μPa at 1 m) and a quieter AHD with longer pulse durations (>50 msec, 166 dB re 1 μPa at 1 m) would be 80 dB or more above the detection threshold of a harbor seal Phoca vitulina were 10 and 3.5 m, respectively. On a quiet day with no nearby vessel traffic, these AHDs would be clearly detectable by harbor seals at ranges up to 2.9 and 1.3 km, respectively. By increasing the pulse length of the louder AHD to >50 msec, the sound would be more than 80 dB above the seal's detection threshold at 100 m but the sound would also be clearly detectable up to 7.2 km. It is technically possible to produce AHDs that are louder. Using very high amplitude sounds to protect finfish aquaculture cages from seal predation without encountering prohibitively large capital and operating costs may not be feasible.
Validation of a Time‐Resolved Fluoroimmunoassay for Measuring Plasma Cortisol in Channel Catfish Ictalurus punctatus
Authors: Small Brian C. , Davis Kenneth B.
Published: April 2007

Abstract.— A time‐resolved fluoroimmunoassay (TR‐FIA) marketed for measuring cortisol in human sera was evaluated and validated for use in the quantification of plasma cortisol concentrations of channel catfish Ictalurus punctatus. Time‐resolved fluoroim‐munoassays provide non‐isotopic alternatives to the use of radioimmunoassays (RIA). The evaluated TR‐FIA satisfied strict criteria of precision (intra‐assay coefficients of variation (CV) < 7%) and reproducibility (inter‐assay CV ≤ 9%). Accuracy of the TR‐FIA, calculated as the percent of exogenous cortisol recovered from spiked catfish plasma, averaged 99.5%. Assay sensitivity (minimum detection limit) in catfish plasma was 1.2 ng/mL, and the displacement curve for serially diluted channel catfish plasma paralleled the cortisol standard curve. Plasma cortisol concentrations of channel catfish in the presence and absence of a confinement stressor were used to characterize the im‐munoreactive cortisol measurable by TR‐FIA, and compared favorably to RIA values for the same samples (r2= 0.95, P < 0.001).
Effects of Egg Size Differences on Juvenile Weight between and within Lots in Rainbow TroutOncorhynchus mykiss
Authors: Blanc J. M.
Published: April 2007

Effects of egg size on weight and growth of juvenile rainbow troutOncorhynchus mykisswere investigated within and between lots, using a genetic variant with “golden” phenotype as a marker. Analysis of between‐lots variation corroborated earlier findings that egg weight influence on the juvenile body weight disappears after a few months of life. In contrast, within‐lot effects of egg size were greater and persisted over a longer time. Egg size did not affect subsequent survival or specific growth of the juvenile trout. The genetic marker caused some detrimental pleiotropic effects on eyed egg yield and juvenile body weight, but not on juvenile survival or specific growth.
A Survey of Infectious Diseases and Parasites of Penaeid Shrimp from the Gulf of Mexico
Authors: Chávez‐Sánchez María Cristina , Hernández‐Martínez Margarita , Abad‐Rosales Selene , Fajer‐Ávila Emma , Montoya‐Rodríguez Leobardo , ÁLvarez‐Torres Porfirio
Published: April 2007

A histopathological survey of wild and cultured shrimp from the Gulf of Mexico was carried out to determine the prevalence and severity of infectious diseases and parasites, affecting four species of penaeid shrimp (Litopenaeus setiferus, Farfantepenaeus aztecus, F. duorarum, and L. vannamei). Around 60 shrimp were obtained from each of 10 sampling stations during different months in 1999 and 2000. One station was a shrimp culture farm from Tamaulipas State, and nine were wild stations from Tamaulipas (five), Veracruz (one), and Campeche (three) States. Thirty shrimp from each station were used for histological analysis. The remaining shrimp were frozen and kept at −20 C to carry out PCR techniques to determine the presence of white spot syndrome virus (WSSV). Some in situ hybridization analyses were applied to ascertain cases of WSS viral disease. Fresh analysis was carried out in shrimp from only one station for parasite identification. The histopathological survey performed on 688 shrimp showed no evidence of viral diseases. Two shrimp from one station were histologically diagnosed as having presumptive WSSV. Tissues from the same shrimp were processed for in situ hybridization and another 20 samples from the same station were processed to run PCR techniques. In each case, the results were negative. The same PCR procedure was applied to the rest of the frozen samples and none of them showed the presence of the WSSV. No important bacterial infections were observed in any of the wild or cultured shrimp analyzed. Fresh analysis demonstrated the presence of the cestode Prochristianella hispida and the gregarines Cephalolobus penaeus and Nematopsis penaeus. Histological analysis showed that the abundance of P. hispida varied from 7 to 90%, and G1 to G4 grades of severity were observed, with G1 being the most common. Gregarines were commonly observed in the histological slides, with a prevalence varying from 3 to 56% and G1 severity in most cases. Haplosporidan infection was observed in one sample of F. duorarum, which is the first report of this parasite in this host. Two invasive epibionts, the filamentous bacteria Leucothrix sp. and the ciliate Ascophrys sp., were found in four sampled stations. The study showed that in ten stations sampled from 1999 to 2000 in the Gulf of Mexico, shrimp populations had no serious infectious diseases.
Growth, Survival, and Feed Conversion Rates of Hatchery‐Reared Mutton Snapper Lutjanus analis Cultured in Floating Net Cages
Authors: Benetti Daniel D. , Matera Jaime A. , Stevens Owen M. , Alarcon Jorge F. , Feeley Michael W. , Rotman Federico J. , Minemoto Yoichi , Banner‐Stevens Gill , Fanke Janice , Zimmerman Scott , Eldridge Loyal
Published: April 2007

Abstract.— The aquaculture performance of mutton snapper Lutjanus analis raised in floating net cages was assessed by measuring their growth, survival, and feed conversion rates during a growout trial conducted in a 3.2‐ha saltwater lake in the Florida Keys, Florida, USA. Approximately 10,500 hatchery‐reared finger‐lings were stocked in two circular, high‐density polyethylene (HDPE) net cages of 7‐m diameter × 7‐m deep (300 m2) and 10‐m diameter × 7‐m deep (600 m3) dimensions. Cages were stocked at 25 fish/m3 (3.2 kg/m3) and 5 fish/m3 (0.72 kg/m3), respectively. Fish grew from a mean of 16.5 g to 302.8 g (25.6 cm TL) in 246 days in the former cage and from a mean of 42.3 g to 245.6 g (23.8 cm TL) in 178 d in the latter cage. Growth rates in weight were best expressed by the following exponential equations: cage 1 (high stocking density): W = 20.716 e0.0112x (r2= 0.83); cage 2 (low stocking density): W = 38.848 e0.0118x (r2= 0.81). Length‐weight data indicate that hatcheryraised, cage‐cultured mutton snapper are heavier per unit length than their wild counterparts. There was no significant difference (P < 0.05) between the slopes of the two lines, indicating that fish in the two cages grew at the same rate. The length‐weight relationships for mutton snapper stocked in cages 1 and 2 are expressed, respectively, by the equations W = 0.000009 L 3.11 (r2= 0.99) and W = 0.000005 L 3.22 (r2= 0.97). Overall feed conversion rate for both cages combined was 1.4. Approximately 10% of the fish sampled exhibited some degree of deformity, particularly scoliosis. Overall survival rate was 70%. Results suggest that L. analis has potential for aquaculture development in net cage systems.
Comparison of the Reproductive Performance of Similarly‐Sized Wild and Captive Farfantepenaeus paulensis
Authors: Peixoto Silvio , Wasielesky Wilson , D'Incao Fernando , Cavalli Ronaldo O.
Published: April 2007

The reproduction of wild‐caught Farfantepenaeus paulensis in captivity has been successfully achieved since 1983. However, year‐round supply of wild broodstock is costly and unpredictable. This study compares the reproductive performance of animals of similar size (females from 32–33 g and males from 19–21 g) but from different sources: estuary‐caught juveniles reared indoors for 9 mo and wild‐caught adults from shallow coastal waters. Groups of 20 males and 30 unilaterally eyestalk‐ablated females were maintained for 60 d in four maturation tanks under controlled environmental conditions. A higher number of eggs per spawning event (78,414 ± 34,491) and total egg production (4,469,600) were observed for the wild females. Nevertheless, captive females produced a higher number of nauplii (1,788,259) due to their higher percentage of fertilized spawns. Therefore, within the size range of this study, the reproductive performance of estuary‐caught F. paulensis juveniles over‐wintered indoors was found to be equivalent to that of wild‐caught females from shallow coastal waters.