bluuebunny/crossref_metadata_2025 huggingface dataset:
TEMPERATURE EFFECTS ON FEED INGESTION AND ASSIMILATION EFFICIENCY OF NUTRIENTS BY THE MALAYSIAN PRAWN, Macrobrachium rosenbergii (de Man)
Authors: Newman Mark W. , Lutz Peter L. , Snedaker Samuel C.
Published: August 2010

Feed ingestion and assimilation of dry matter, total lipid, total carbohydrate and inorganic material by adult, male Macrobrachium rosenbergii (de Man) were measured at temperatures ranging from 22–34°C. Assimilation efficiency of dry matter was measured gravimetrically. Significantly less feed was ingested by prawns at water temperatures below 25°C than at higher temperatures. Water temperatures had little effect on the assimilation efficiency of dry matter, although there was a trend toward decreased dry matter assimilation at high temperature extremes. There was no effect of water temperature on assimilation efficiencies of lipid, carbohydrate or inorganic material. It is proposed that feed ingestion and metabolic rates are affected more by water temperature and are more responsible for differences in growth rates than is the efficiency of feed assimilation.

Regurgitation was a consistent occurrence following feeding by prawns and accounted for a significant proportion of egested material. It is suggested that regurgitation results in energetic benefits to the prawn, owing to a decreased energy requirement because unassimilable material need not be transported through the entire digestive system. There may also be an increase in the rate of energy intake due to the clearance of ingested, but unassimilable, material from the proventriculus. The absorption of minerals from the diet and the phenomenon of regurgitation are taken into account in a critical discussion of assimilation determination methods used for aquatic invertebrates.
INCREASED LARVAL PRODUCTION OF Penaeus setiferus BY ARTIFICIAL INSEMINATION DURING SOURCING CRUISES
Authors: Bray William A. , Chamberlain George W. , Lawrence Addison L.
Published: August 2010

The inability of shrimp culturists to produce sufficient quantities of fertilized penaeid eggs in captivity has sustained the practice of collecting mature wild females offshore for immediate spawning. However, in the case of open thelycum penaeids, offshore collections are often unproductive because mature wild females are seldom found in the mated (spermatophore attached) condition. In this study, artificial insemination was investigated as a means of obtaining fertilized eggs from unmated mature female Penaeus setiferus collected offshore.

A total of 59 artificial inseminations were performed in conjunction with 4 cruises in the western Gulf of Mexico. Sperm was removed from spermatophores of males found within the catch and attached between the third and fourth pairs of pereiopods of unmated, mature females which were then chilled to 20°C to inhibit spawning until return to the laboratory. Of 53 spawns produced by artificially inseminated females, at least 41 (77%) resulted in fertilized eggs and nauplii (range: 100 to 260,000 nauplii per spawn). Of the 41 fertile spawns, 29% produced 50,000 or more nauplii and 20% produced more than 100,000 nauplii per spawn. Approximately 2 million larvae were produced by artificial insemination, while only about one million were obtained from naturally mated females on the same cruises. Thus, the production of nauplii from the cruises was tripled by using artificial insemination in addition to spawning of naturally inseminated females.
THE USE OF AMYLASE SUPPLEMENTS IN SHRIMP DIETS
Authors: Maugle Paul D. , Deshimaru Osamu , Katayama Teruhisa , Simpson Kenneth L.
Published: August 2010

Two experiments were conducted to examine the effect of varying amounts of casein and starch relative to the amount of an α‐amylase supplement on shrimp growth and digestive processes. Amylase was supplemented to diets containing 9.5, 19.0 and 28.5% starch in a freeze‐dried nylon‐protein microcapsule form in order to circumvent potential inactivation.

After a 30‐day feeding period, shrimp fed diets containing 19.0% and 28.5% starch, and supplemented with approximately 60 IU amylase/g‐dry‐diet were significantly larger (P < 0.05) than diets with no amylase or a live short‐necked clam control diet. Shrimp fed 9.0% starch attained a greater mean weight than those fed 28.5% starch. These findings, evaluated collectively, indicate that a 60 IU amylase/g‐dry‐diet supplement was adequate for complete utilization of dietary starch at the 19.0% level but not at the 28.5% level.

In a second study which used chromic oxide to examine the effect of an amylase supplement on the digestibility ratio of dietary starch, almost complete digestion (95.7%) was found in the group fed the α‐amylase supplemented diet containing 19.0% starch, as compared to 89.5% digestibility in the group without the amylase supplement.

These studies show that up to 30% of the casein in the diet could be substituted with starch on equal weight basis without a substantial reduction in weight gain or feed efficiency, with supplementation of α‐amylase. This may allow future development of more cost effective diets.
POND CULTURE OF Penaeus monodon IN THE PHILIPPINES: SURVIVAL, GROWTH AND YIELD USING COMMERCIALLY FORMULATED FEED
Authors: Liu Mao‐Sheng , Mancebo Victor J.
Published: August 2010

Pond culture of Penaeus monodon was undertaken in the Philippines using artificially formulated dry feed and hatchery‐produced post‐larval shrimp. The trial was conducted in two 0.25‐ha managed production ponds with earthen bottoms and concrete dikes. Water depth was 1.1 m; brackish water was used and the salinity ranged from 7 to 17 ppt.

For the trial, from 22 June 1982 to 6 October 1982 (106 days), the ponds were stocked at 158,000 postlarvae/ha and produced, respectively, 4,008 kg/ha and 3,808 kg/ha of heads‐on shrimp averaging 31.5 g and 31.3 g in size. Survival in the respective ponds was 80% and 77% with food conversions of 1.69 and 1.78.

Based on the costs for postlarvae, feed, labor and power, the shrimp were produced with a positive economic return. The production costs per kilo of whole shrimp produced in each pond were, respectively, US$4.40/kg and $4.63/kg. The entire crop of shrimp was sold heads‐on for an average price of $6.78/kg.
AN INEXPENSIVE AND SIMPLE RACEWAY DESIGN1
Authors: Kneale Douglas C. , Salman Shukri E. , Al‐Ahmed Abdul‐Kader A. , Farmer Anthony S. D.
Published: August 2010

Intensive aquaculture systems tend to require a large capital investment and be relatively complicated to manufacture or construct with the result that a particular application may be unprofitable or difficult to implement. Raceways have been developed in Kuwait utilizing reinforced plastic liners supported by a wooden railing. Shrimp (Penaeus semisulcatus) were raised in these raceways in order to assess the system. The design allows for easy maintenance, observation and harvest. In addition, the simplicity of the concept assures low material, construction and manpower costs, requiring neither a building contractor nor special tools. A 3.0 m wide raceway of this design costs approximately US$ 17 m‐2 in Kuwait. This paper describes the raceway design and construction techniques, and compares the cost with other materials and systems in Kuwait. The results of shrimp rearing trials are discussed with regard to the durability, management and biological compatibility of the design.
ENCLOSED PRAWN NURSERY SYSTEMS AND EFFECTS OF STOCKING JUVENILE Macrobrachium rosenbergii IN PONDS1
Authors: Smith Theodore I. J. , Jenkins Wallace E. , Sandifer Paul A.
Published: August 2010

In temperate areas the stocking of small juveniles may be required for pond culture of prawns, Macrobrachium rosenbergii, to be economically attractive. Twelve nursery trials were conducted focused primarily on a two‐phase nursery system. In phase I trials, prawns grew from 0.01 g to 0.2‐0.4 g at densities of 1,194‐6,276 prawns/m2 tank bottom during 67–105 days. Estimated survival rates at densities of 1,194‐1,663/m2 were comparable after 4, 8, and 12 weeks of culture and averaged 96, 93, and 90%, respectively. At high densities survival rates were substantially lower. in the phase II trials, prawn stocking size varied from 0.09‐0.70 g and density from 538–904/m2. Prawns attained a weight of 0.9‐2.1 g during 42–64 days of culture. Estimated survival averaged 91% after 4 weeks and 84% after 8 weeks. One monophasic or continuous phase trial was conducted at a density of 323/m2. During this 8‐week trial, prawns grew from 0.05 to 1.64 g and exhibited a survival rate of 92%.

The biological and economic effect of stocking larger juveniles (1 and 2 g size) was estimated for seasonal pond production of prawns. when 1 and 2 g prawns were stocked in ponds at a density of 43,100/ha, final prawn size increased 13 and 25%, respectively, and total production increased 111 and 208 kg/ha. At stocking density 64,600/ha, harvest size of prawns increased 17 and 27%, respectively, and production increased 183 and 299 kg/ha. Estimated revenues were increased when the additional cost of producing or purchasing these large juveniles was ≤ $15/1,000 for 1 g animals or ≤ $30/1,000 for 2 g animals.
IMMUNIZATION OF SALMONIDS AGAINST THE FISH PATHOGEN, Aeromonas salmonicida
Authors: Cipriano Rocco C. , Morrison J. K. , Starliper C. E.
Published: August 2010

An avirulent strain of Aeromonas salmonicida was shown to lack “A‐layer” protein exterior to the outer cell membrane, but was still immunogenic in fish. After bacteria were inactivated with chloroform, whole cells, soluble antigen and combined whole cell plus soluble antigen vaccines were prepared. Those brook trout (Salvelinus fontinalis) that were vaccinated by a 60‐second immersion in the combined whole cell plus soluble antigen vaccine were protected against experimental challenges. Further immersion vaccinations of Atlantic salmon (Salmo salar) in the combined vaccine indicated that protection conferred by immunization was highly significant, efficacious, and reproducible. In field situations, mortality in brown trout (S. trutta) immersion‐vaccinated in this preparation was 2.1% whereas that in control fish was 28.9% after natural challenge.
THE EFFECTS OF WATER TEMPERATUHE ON INFECTION AND ANTIBODY FORMATION INDUCED BY Vibrio anguillarum IN JUVENILE COHO SALMON (Oncorhynchus kisutch)1
Authors: Groberg W. J. , Rohovec J. S. , Fryer J. L.
Published: August 2010

Effects of environmental temperature on juvenile coho salmon (Oncorhynchus kisutch) experimentally infected with Vibrio anguillarum were examined at 7 water temperatures from 3 to 21°C. The mean day to death and total mortality were each related to temperature. The shorter mean day to death and higher mortality were observed at the elevated water temperatures. Growth curves of V. anguillarum cultured in Brain Heart Infusion broth were determined at 6, 12 and 18°C. Growth rates were directly related to temperature. The effect of temperature on the production of V. anguillarum agglutinating antibodies following parenteral injection was determined in juvenile coho salmon held at 6, 12 and 18°C. Titers were first observed on days 10, 15, and 25 in fish held at 18, 12 and 6°C, respectively.
PATHOGENESIS OF Edwardsiella ictaluri IN CHANNEL CATFISH, Ictalurus punctatus
Authors: Areechon Nontawith , Plumb John A.
Published: August 2010

Channel catfish fingerlings were injected intraperitoneally with 2.0 times 104 viable Edwardsiella ictaluri cells. During the subsequent 4 days hematological and histopathological changes were determined, and bacterial counts were made in selected organs. There were significant reductions in erythrocytes and leucocytes. The mean corpuscular volume, and mean corpuscular hemoglobin concentration did not change significantly. Mean corpuscular hemoglobin changed significantly only at 72 hours. The hematocrit, hemoglobin, plasma glucose and plasma protein were reduced significantly. There were no significant changes in differential white blood cell counts. The liver was edematous and necrotic while the pancreatic tissue was necrotic. The spleen and trunk kidney appeared necrotic and an increase of lymphoid cells was also observed. Edema and cloudy swelling were observed in gill lamellae. Intestine and stomach were normal. Bacteria were abundant in spleen, trunk kidney and liver. Bacteria reached the maximum population at 96 hours post injection and declined at 6 days in all three organs.
CRAWFISH CULTURE SYSTEMS AND THEIR MANAGEMENT
Authors: Lawson Thomas B. , Wheaton Fredrick W.
Published: August 2010

Crawfish are cultured in shallow, open ponds surrounded on all sides by levees. To insure high production it is essential that high quality water be maintained in the pond. Ponds should be constructed in such a fashion that aerated water is circulated through all areas of the pond in order to avoid areas of low oxygen. With good quality water and sound management practices up to 2,200 kg ha‐1 or more of crawfish may be produced annually.
A PHYSIOLOGICAL APPROACH TO MARICULTURE OF RED ALGAE
Authors: Hansen Judith E.
Published: August 2010

Algal mariculture research at Hopkins Marine Station (Stanford University) and Marine Bioassay Laboratories (Watsonville, Calif.) led to the development of a critical pathway approach: ecological studies, strain selection, physiological experimentation, and cultivation trials. Initial ecological studies focused on seasonal growth and life history patterns of Gelidium and Gracilaria. The results provided the clues for selection of experimental tolerance ranges for key physical and chemical parameters to be studies. Plant vigor and the algal products of interest were the primary criteria in the strain selection program. The metabolic response patterns for net photosynthesis of the species were then studied to characterize the presumptive environmental optima and tolerance ranges for these red algal cultures. The results from these shortterm physiological experiments are tested in algal cultivation trials. The results from this critical pathway approach were: 1) selected, vigorous strains; 2) basic requirements for cultivation of the species; 3) predictions of how the species will respond in culture; 4) production estimates for use in mariculture feasibility models; and 5) a definition of conditions which must be met by a specific culture technique. This research, which takes place primarily in the laboratory, provides the foundation for development of the capital‐intensive, pilot mariculture system for a specific red algal species.
CLONING MARINE ALGAE FOR MARICULTURE
Authors: Waaland J. Robert
Published: August 2010

Traditional marine algal mariculture relies on spores or gametes for inoculation of artificial substrates on which the algae are grown to harvest size in open waters. In the case of Porphyra and Laminaria mariculture, this process has reached a high level of sophistication. Newly established seaweed mariculture industries growing Eucheuma and Gracilaria have employed vegetative propagation techniques successfully in artificial substrate or pond culture of these algae. Successful manipulation of the regenerative potential of small, mass‐produced vegetative fragments of certain marine algae, notably Gigartina and Porphyra, has recently been used to inoculate artificial substrates with clones of these algae in experimental mariculture studies. Methods of fragment production and their inoculation on artificial substrates are described. Early development, transplantation to the field, survival in the field and subsequent growth and longevity are also described. Strain selection and maintenance of genetic stocks of cultivars can be greatly facilitated if spore or gamete reproduction can be bypassed by cloning methods. A relatively small amount of material may be used to inoculate large amounts of substrate using such cloning methods. Uniformity of response to environmental factors and uniformity of the resulting crop are advantages of the use of cloning techniques in algal mariculture.
GROWTH AND FOOD UTILIZATION OF CAGED ATLANTIC CROAKER AND STRIPED MULLET REARED ON VARIOUS LIPID DIETS IN A HEATED WATER SYSTEM
Authors: Jones Fredrick V. , Strawn Kirk
Published: August 2010

Atlantic croaker and striped mullet were caged‐cultured in the cooling lake of a power plant near Baytown, Texas, from 30 May to 2 September 1978 to determine the effects of semi‐purified diets on growth. These diets varied in the type of lipid utilized (fish oil, beef tallow or soybean oil). Temperature, salinity, pH and dissolved oxygen were monitored to determine growth rates.

Survival was generally high, ranging from 80 to 100%, except for one cage of croaker which broke from its mooring line resulting in an 80% loss. Total production ranged from 3.1 to 5.4 kg/m3 and 0.55 to 2.5 kg/m3 for Atlantic croaker and striped mullet, respectively. Percent gains and production were highest for fish fed diets containing fish oil as a lipid source, rather than beef tallow or soybean oil.
INDUCED SEX INVERSION, MATURATION, SPAWNING AND EMBRYOGENY OF THE PROTOGYNOUS GROUPER, Mycteroperca microlepis
Authors: Roberts Daniel E. , Schlieder Rodric A.
Published: August 2010

Female gag (Mycteroperca microlepis) were collected from the Eastern Gulf of Mexico, maintained in closed systems and spawned. Sex inversion of this protogynous grouper was induced with oral application of methyl‐testosterone. Ovotestes of transitional males were described. Photo‐period, temperature, and hormome application were utilized to induce maturation and ovulation of females. Approximately 26,000 eggs were produced in 2 spawns. Fertilization rate was 50%. Larvae hatched after 45 hours at 21.0°C. Embryonic and early larval stages were described.
PROSPECTS FOR COMMERCIAL NETCAGE CULTURE OF RED GROUPER (Epinephelus akaara T. & S.) IN HONG KONG
Authors: Tseng Wen‐Young
Published: August 2010

The red grouper (Epinephelus akaara T. & S.) is non‐gregarious. It likes to inhabit crevices and caverns which are formed by the reefs and artificial materials in natural waters. They have a wide tolerance to salinity, temperature and oxygen requirement. Crustaceans and fish seem to be their favorite food. Live fish have a high market demand in Hong Kong. More than 70% of the live fish is provided directly or indirectly from aquaculture. Around 25,000 cages are engaged in culture at present, and 600–900 tons of cultured fish are produced annually. Natural fingerlings are the main seed source, but there is still a 30–50% shortage of fingerlings, and although induced spawning was successful two years ago, mass production of fingerlings still has a long way to go.

Several culture methods such as cage, barrier, dam, pond and reef culture are employed in Hong Kong. Among these, cage culture is predominant, with a very bright and promising future.
PERFORMANCE OF DOMESTIC AND DOMESTIC X WILD CROSSES OF CHANNEL CATFISH IN TWO WATER TEMPERATURES1
Authors: Bondari K.
Published: August 2010

Domestic x Domestic, Domestic x Wild, and Wild x Wild channel catfish (Ictalurus punctatus) were paired in individual spawning pens and subsequent egg masses were artificially incubated. Domesticated catfish originated from 5 different hatcheries located in Georgia, Alabama, and Mississippi and since 1974 had undergone selective breeding for 2 generations for multiple traits. Wild catfish were collected from Carlyle and Shelbyville reservoirs in Illinois and were transferred to Tifton, Georgia, for this study. None of the 8 Wild x Wild pairs spawned in captivity, but the 8 Wild ♂ x Domestic ♀ and the 8 Domestic ♂ x Wild ♀ produced 3 and 6 egg masses, respectively. The fry hatched from each of the 14 egg masses (5 from Domestic x Domestic) were standardized to 2 tanks of 500 fish each at 4 weeks of age where one tank received 22°C well water and the other 28°C from 4–12 weeks. The fish from both tanks were grown in a constant 22°C water temperature from 12–40 weeks. The objective was to produce crossbreds superior to both parents in growth and survival in 22°C well water. An increment of 6°C in water temperature for a period of 8 weeks increased body weights of both straightbred and crossbred catfish by 100%. Domestic x Domestic catfish outperformed the Domestic x Wild crossbreds in both temperature regimes. These results suggest a stronger need for growth improvement through selective breeding of channel catfish than crossbreeding with wild strains.
ECOLOGICAL AQUACULTURE, NEW APPROACHES TO AQUACULTURE IN NORTH AMERICA
Authors: MacKay K. T.
Published: August 2010

Existing aquaculture systems in North America are energy intensive. For example, rainbow trout production in raceways requires an energy subsidy of 81 MJ/Kg while catfish pond production requires 44 MJ/Kg; both are more energy intensive than feed lot beef production. An alternative approach, “ecological aquaculture,” has been practiced for centuries in Asia but has only recently been applied in North America. Ecological aquaculture is energy efficient, recycles wastes, minimizes environmental impact, and is integrated with other food production systems. This paper discusses the principles of ecological aquaculture and illustrates them with examples from North American operations. Such operations range from extensive culture of rainbow trout in small productive prairie ponds to greenhouse water recirculation systems with fish supplying the nutrients for hydroponic crop production. Other examples are backyard fish production systems and polyculture pond systems fertilized by pig manure.
SOURCING Penaeus setiferus: A SUMMARY OF LARVAL PRODUCTION, INCIDENCE OF CAPTURE OF MATED FEMALES, AND MATING INCIDENCE BY TIME OF DAY ON RESEARCH CRUISES 1981–1983
Authors: Bray William A. , Lawrence Addison L.
Published: August 2010

Results of 32 collection cruises for Penaeus setiferus adults over a 3‐year period in the northwestern Gulf of Mexico are reviewed to document incidence of capture of mature females, mating incidence by time of day of capture, and larval production from natural and artificial inseminations. Mean number of eggs per spawn by year for natural inseminations ranged from 197,000–309,000 (n=160) and for artificial inseminations, 136,000–300,000 (n=174) for females averaging 38–45 g. Mean percent hatch for natural inseminations ranged from 35.3–72.8, and for artificial inseminations, 14.7–77.8. The percentage of females captured from 0900–1600 hours which were mated ranged from 0–13%, while 9–42% of those captured from 1600–2200 hours were mated. The strongest diurnal increase in mating activity occurred from 1600–1800 hours. Three mated conditions, characterized by 1) a complete compound spermatophore; 2) the “wings” or anterior portion of the spermatophore only; and 3) a sperm mass only, represented 28.4%, 38.3%, and 33.3%, respectively, at time of capture. A significant relationship was found between spermatophore stage and hour of capture (P < 0.149), suggesting there may be a sequential breakdown of the spermatophore prior to spawning.
MECHANICAL SIZE GRADING OF POSTHARVEST PRAWNS1
Authors: Arndt Gerald D. , Gautz Loren D. , Wang Jaw‐Kai
Published: August 2010

An inexpensive and simple mechanical size grader for freshwater prawns was developed, utilizing a pair of diverging rollers (114 mm diameter and 90 cm length). Five machine variables were studied using a two‐level fractional factorial sequential search technique. Optimum roller speed was 100 RPM, with an optimum roller incline of 10 percent. Space between rollers was 20 mm at the entrance and 29 mm at the exit. At a recomnended feeding rate of 3 prawns every 3 seconds, 90 percent correct sorting of market sized prawns was achieved.
PRELIMINARY STUDIES OF PROTEIN SYNTHESIS, GLUCONEOGENESIS AND LIPOGENESIS WITH LABELLED U 14C GLUTAMATE IN COHO SALMON: EFFECT OF SEA TRANSFER
Authors: Guillaume J. , Stéphan G. , Messager J. L. , Garin D.
Published: August 2010

This experiment was carried out in two groups of coho salmon (Oncorhynchus kisutch) hatched in early 1982 in Brittany (France). The biggest fish (group 1) had been kept in freshwater, although smoltification had been evident during autumn 1982. The smallest fish (group 2) had not smoltified. In April 1983, fish of group 1 resembled smolts (average weight about 300 g) again while those of group 2 looked like parr (average weight about 40 g). At that time, injections of U 14C glutamate were made intraperitoneally and measurement of the incorporation of 14C into protein, glucose and lipids of plasma, liver and muscle was performed after 2, 3 or 5 hours. This operation was repeated in June on batches of salmon out of group 1 that were transferred, either into seawater (SW) or freshwater (FW) tanks. At that time, the fish were either fully adapted to SW or “desmoltified” in FW.

The results show in groups 1 and SW very clear modifications of the use of glutamate as compared with groups 2 and FW: gluconeogenesis is enhanced; apparent protein anabolism is enhanced in liver, but depressed in muscle. Apparent lipogenesis from glutamate is sharply decreased; therefore preparation for, and adaptation to, seawater induces clear changes in the intermediary metabolism.

A second experiment was carried out in October 1983 in fish, where gill ATPase was measured to confirm that the modifications were due to smoltification itself. The effects of autumn smoltification are, however, very different from those observed in spring.
SURVIVAL OF CAGE CULTURED BLACK DRUM, ATLANTIC CROAKER, AND STRIPED MULLET IN UPPER ESTUARINE WATER IN RELATION TO LIFE HISTORY STRATEGY
Authors: Jones Fredrick V. , Strawn Kirk
Published: August 2010

Black drum (Pogonias cromis), Atlantic croaker (Micropogonias undulatus), and striped mullet (Mugil cephalus) were cage cultured in a cooling lake of a power plant near Baytown, Texas, from 1 September 1976 through 1 September 1978 and observations on the effects of water temperature and salinity on their survival are reported.

The heated‐water system was typified by high variability of and rapid drops in salinity in the intake area which moderated as water was mixed during passage through the cooling lake. Temperature averaged 11.1°C higher in the discharge canal than in the intake area, but was only about 1–2°C higher in water discharged into Trinity Bay.

Survival of fishes was low in the intake area and increased progressively through the cooling lake. The most important relationship relating to mortality was the temperature‐salinity‐size interaction. Immature fish were tolerant of low temperatures combined with rapidly dropping salinity whereas older sciaenids which would normally have migrated out of the system if not caged died.
SALMONID MARINE REARING IN FRANCE
Authors: Boeuf Gilles , Harache Yves
Published: August 2010

In a preceding paper in 1980, the status of marine salmonid rearing in French coastal waters was described and the prospects analyzed. After a period of rapid increase in production (1976–1980) a plateau was reached, and in 1983 total marketed production remained below 450 metric tons. The major part of this production was composed of rainbow trout, with coho salmon and brown trout staying at a limited scale. The causes of this evolution and the possible ways of influencing further development of this activity are discussed. Among the major factors influencing production, environmental parameters (temperature, salinity), availability of juveniles, production costs of the marine phase and market acceptability are analyzed. We include a discussion about competition with marine aquaculture products of northern Europe and the emerging production of large size rainbow trout in freshwater in southern areas of France. The major inputs to be expected from research progress and their applicability to the production phase are discussed.
CAGE CULTURE OF RED TILAPIA IN PRAWN AND SHRIMP PONDS
Authors: Meriwether Frank H. , Scura Edward D. , Okamura Wayne Y.
Published: August 2010

Feeding trials were conducted in prawn ponds (freshwater) and shrimp ponds (brackishwater) with red tilapia stocked in floating 0.8‐m3 cages. Pond sizes ranged from 0.23 to 0.45 ha. Seven ponds were stocked at a density of 26 cages/ha. One hundred 9‐9 tilapia fingerlings were stocked into each cage. Fish survival after 8 weeks averaged 98.5% excluding a set of six cages from one pond which was preempted from the study due to high mortality, possibly caused by algal toxins. The growth of caged tilapia fed supplemental diets was significantly (α = .05) higher in brackishwater than in freshwater ponds. Tilapia raised in freshwater cages without supplemental feeding grew at a significantly lower rate than caged fish in any other treatment analyzed. Feed conversion rates were calculated for caged fish grown in fresh water and brackish water. The costs and revenues derived from this polyculture strategy were analyzed. Gross profitha of brackishwater red tilapia cage culture is estimated to be more than double the gross profit obtained in freshwater ponds.
PROLIFERATIVE KIDNEY DISEASE (PKD) IN PACIFIC SALMON AND STEELHEAD TROUT
Authors: Hedrick R. P. , Kent M. L. , Rosemark R. , Manzer D.
Published: August 2010

Proliferative kidney disease (PKD) was detected for the first time in Pacific salmon at a California State Hatchery in June 1983. Both chinook (Oncorhynchus tschawytscha) and coho (O. kisutch) salmon and steelhead trout (Salm gairdneri) held at the hatchery contracted the disease. The cumulative mortality attributed to the disease was 95, 13 and 18% respectively. The mortality rate was greatest during the month of July when the water temperatures were 58–60°F (14–16°C). The protozoan causing PKD was detected in the kidney, spleen, liver, gills and pyloric‐ceca of affected fish. Although lesions typical of Renibacte‐rium salmoninarum infection were found in the kidney of one chinook salmon, all other fish examined were free of complicating bacterial or viral diseases. The ultrastructural features of the protozoan observed in the three species of affected fish were consistent with those described for the parasite in rainbow trout (Salmo gairdneri) in European outbreaks.
POLYCULTURE OF CHINESE CARPS AND PRAWNS AT COMMERCIAL DENSITIES AND REDUCED FEEDING RATES I. WATER AND SEDIMENT MICROBIAL ECOLOGY
Authors: Costa‐Pierce Barry A. , Clay Laurel , Malecha Spencer R. , Laws Edward A.
Published: August 2010

The ecology of water and sediment microbial communities was examined over a 28‐week period in semi‐intensive prawn monoculture ponds and fish/prawn polyculture ponds stocked with commercial densities of silver and grass carp but fed at 50% and 1% of control feeding rates. Fish polycultures at reduced feeding rates had little effect on phytoplankton biomass parameters (concentrations of ATP, chl a), total nitrogen and phosphorus concentrations (TN, TP) and total organic carbon (TOC) during the experimental period. However, fish polyculture ponds fed at reduced rates had significantly increased rates of primary production, microbial DNA synthesis, dissolved organic carbon (DOC) concentrations, and surface sedimentary oxygen consumption rates compared to controls.

High rate plyculture ponds fed at one‐half (20 kg·ha‐1·d‐1) the control monoculture ponds (40 kg·ha‐1· d‐1) had two times (2X) lower suspended organic matter (SOM) concentrations at 13 weeks, lower surface sediment ATP concentrations at 9 weeks, less within‐pond variability in surface sediment ATP concentrations, and higher sedimentary respiration rates than controls. Polyculture ponds fed at 0.4 kg·ha‐1· d‐1had 3X less SOM than controls but had sedimentary respiration rates similar to the high rate polyculture ponds.

In short, fish polycultures in intensive prawn aquaculture ponds combined with reduced feeding rates may be a simple solution to the pervasive problems of water quality control, benthic reducing conditions and decreased prawn growth characteristic of semi‐intensive aquaculture ponds under continuous cultivation.
PREVENTING PREDATION IN MOLLUSCAN MARICULTURE: AN OVERVIEW
Authors: Jory Darryl E. , Carriker Melbourne R. , Iversen Edwin S.
Published: August 2010

Even after many decades of study, predation remains one of the major hurdles to successful field mariculture of molluscs in many areas of the world. Traditional predator control methods include physical barriers (such as trays and enclosures), off‐bottom culture, chemical poisons, removal and trapping, dredges, mops, X‐ray sterilization, and biological means. Most of these methods have produced only limited success, though two or more methods in combination (such as enclosures and active predator removal) are effective hut are expensive. Examples of recent attempts at predator control include protective covers for Manila clams, floating cages for queen conchs, substrate modifications for hard clams, suspension systems for oysters and scallops, and research on development of predator attractants. The ecological concepts of “Size Selective Predation,” “Optimal Patch Use,” “Prey Switching,” “Ingestive Conditioning,” and “Search Image Formation” and their relevance to effective predator control in molluscan field culture are discussed.
PRODUCTION OF CAGED CHANNEL CATFISH IN AN ILLINOIS SURFACE MINE LAKE
Authors: Stickney Robert R. , Moy Philip B.
Published: August 2010

Channel catfish (Ictalurus punctatus) fingerlings representing four size ranges (5.1–10.2, 10.3–15.2, 15.3–20.3 and 20.4 to 25.4 cm) were reared in 0.28 m3 cages at densities of 600 fish/m3. Five replicate cages containing each size group were stocked in a surface mine lake of approximately 1.5 ha in late June, 1984. The fish were fed six days per week at the rate of 3% of body weight with feeding rate adjustments every two weeks. At harvest in mid‐October, 1984, fish stocked at an initial length range of 20.4–25.4 cm were of marketable size on average (379.8 g). Fish in the next smaller size range were marginal for marketing on the average, while those in the two smallest size ranges were submarketable. Results indicated that single season production of channel catfish in cages in southern Illinois would require the stocking of relatively large fingerlings; however, small fingerlings could be easily reared to market size in less than two complete growing seasons. The technique could provide food for owners of such water bodies and might provide supplemental income.
EFFECTS OF CUMULATIVE LOADING LEVEL, AS FISH WEIGHT PER UNIT FLOW, ON WATER QUALITY AND GROWTH OF LAKE TROUT
Authors: Meade James W. , Ramsey John S. , Williams John C.
Published: August 2010

Lake trout, Salvelinus namaycush, were cultured in a series of five rearing units (in triplicate). The fish removed available oxygen in each unit, from about 10.5 to 7.0 mg/L. Oxygen was replaced, through aeration, between rearing units. Effects of cumulative loading, as fish weight/flow rate, are described in terms of water quality and fish growth. In fish reared at the highest loading level, mean growth during the 2‐month cumulative loading period was depressed by more than half. However, the growth rate progressively increased in those fish reared under high loading levels, indicating acclimation of the fish to high metabolite concentrations. After two months of series‐reuse rearing, cumulative loading was removed through introduction of fresh water (noreuse) to each unit, and fish recovery was monitored. During recovery, mean growth of fish that had been reared under the highest cumulative loading level was equal to or greater than that of fish that had been reared under the low loading levels.
THE ECONOMIC AND MARKET POTENTIAL FOR HYBRID BASS AQUACULTURE IN ESTUARINE WATERS: A PRELIMINARY EVALUATION
Authors: Liao David S.
Published: August 2010

The costs and returns of hybrid bass aquaculture were evaluated based on experimental production data in South Carolina. The market potential for hybrid bass was examined based on market price and volume of striped bass on the East Coast during the past two decades. This preliminary assessment indicates that the economic outlook of commercial aqua‐culture of hybrid bass in estuarine waters appears promising. With current technology, prices in the $5.50/kg or higher range would generate some profits for aquafarms. However, the major concern at present is legal restrictions on commercial production and marketing of hybrid bass in South Carolina.
COMBINED EFFECTS OF SHRIMP SIZE AND DIETARY PROTEIN SOURCE ON THE GROWTH OF Penaeus setiferus AND P. vannamei
Authors: Chen Houng‐Yung , Zein‐Eldin Zoula P. , Aldrich David V.
Published: August 2010

Three size classes of juvenile Penaeus setiferus (average wet weight = 0.08, 0.99, and 3.82 g) and P. vannamei (average wet weight = 0.12, 1.39, and 4.72 g) were kept 3 weeks in indoor tanks at 28°C, and each of 3 isonitrogenous (28% protein) experimental diets were fed to each size class. Shrimp meal of a basal experimental diet was replaced by fish protein hydrolysate, soybean meal, and cotton seed meal to achieve animal:plant (A:P) protein ratios of 1:1.5, 0.9:1, and 1.5:1 in the 3 diets. Penaeus vannamei grew faster than P. setiferus given the same diets. For both species, A:P ratios of food improved growth for all 3 size categories of shrimp. This effect was significantly greater in the small animals than in the medium or larger‐sized ones. Thus, the quality of diet needed to achieve maximum growth appears to be size dependent, smaller shrimp being more dependent than larger ones on animal protein. Results also indicated that the two larger size classes of P. setiferus require higher animal protein in their feed for maximum growth than do similar size classes of P. vannamei.
GROWTH. FEED DIGESTIBILITY, AND PROXIMATE BODY COMPOSITION OF JUVENILE Penaeus vannamei AND Penaeus monodon GROWN AT DIFFERENT DISSOLVED OXYGEN LEVELS
Authors: Seidman Ephraim Ross , Lawrence Addison Lee
Published: August 2010

Growth, feed digestibility (apparent total dry‐matter digestibility), and proximate body composition of juvenile Penaeus vannamei and Penaeus monodon were evaluated at dissolved oxygen (DO) levels of 1, 2, 3, and 4 ppm at a mean temperature of 28°C. The four different W levels were obtained by aerating different rates of nitrogen gas countercurrent to a constant flow of seawater. A standard formulated diet containing the marker material Cr2O3, and a mean 280% exchange of 30 to 32 ppt seawater per day were used. Initial wet weights of shrimp were 60.2 and 55.5 mg for P. vannamei and P. monodon, respectively. Final mean wet weights for shrimp maintained at 1, 2, 3, and 4 ppm DO level after a 16‐day growth trial were 0.24, 0.40, 0.42, 0.46 g, and 0.16, 0.26, 0.29, 0.29 g for P. vannamei and P. monodon, respectively. For both species, a significant reduction in growth and in the instantaneous growth rate (k) was obtained at the lowest Do level. No significant differences were observed for apparent feed digestibility in either shrimp. Laboratory analysis revealed no differences in moisture and lipid content for both species, while protein content was found to differ only in P. monodon grown at different DO levels. A description of the experimental system and a discussion of the significance of the data to the production of shrimp in ponds is presented.
LABORATORY AND POND EVIDENCE FOR SHRIMP (Penaeus stylirostris) PREDATION BY DAMSELFLY NYMPHS (Ischnura rarnburi)
Authors: Huang Hann‐Jin , Aldrich David V. , Strawn Kirk
Published: August 2010

A negative relationship was found between damselfly nymph population density and final shrimp population density in ponds. The importance of damselfly nymphs as potential predators of post‐larval shrimp and the effect of shrimp size, salinity, and substrate type on this predatory relationship were evaluated by a series of laboratory experiments. When 5–10 nymphs and 15 post‐larval shrimp were stocked in tanks with a 0.96 m2 bottom area and containing 150 liters of water, each nymph averaged killing 1.7 shrimp per day at 10 ppt salinity and 0.6 shrimp per day at 20 ppt. Damselfly predation rates were inversely related to the three shrimp sizes (average 8.55, 12.89, and 17.30 mm). Presence or absence of a natural muddy substrate had no effect on shrimp mortality caused by nymphs. The results of these experiments strongly suggest that predation of damselfly nymphs on post‐larval shrimp, when they occur together in ponds, may be a serious problem for the culturist.
INTEGRATED POND CULTURE: A TYPE OF SPATIALLY SEQUENTIAL POLYCULTURE
Authors: Chien Yew‐Hu , Tsai Wen‐Shiung
Published: August 2010

Polyculture, the culture of two or more aquatic species in a single culture unit, has proven ecologically sound and practical. However, when cultured organisms have different physical needs or have antagonistic (competitive or predator‐prey) relationships, successful polyculture becomes unlikely. To remove the constraints without loss of the advantages of polyculture, an alternative system of “integrated pond culture” has evolved. The antagonistic species are cultured in discrete ponds which maintain contact only through the flow of nutrients and food organisms. By simple engineering and proper coordination of the ponds, this system shows promise for conserving water, energy, and especially nutrients. This is reflected in reduced operating cost in stocking, feeding and harvesting. Comparisons are made of polyculture and integrated pond culture with regard to aspects of management, engineering, economics and ecology.
NEW DEVELOPMENTS IN THE HIGH DENSITY FLOW‐THROUGH CULTURING OF BRINE SHRIMP Artemia
Authors: Lavens Patrick , Baert Paul , de Meulemeester Alain , Van Ballaer Erik , Sorgeloos Patrick
Published: August 2010

A closed culture system for the high density culturing of Artemia spp. in 300‐liter tanks using a new formula of artificial seawater and micronized waste products frm agricultural crops as food is described. Culture conditions are greatly improved by applying a new filter technique and an electronic transparency meter which controls food distribution automatically. A total volume of 6,000 liters of culture water is recirculated over a rotating biological contactor, a cross‐flow sieve and a plate separator at a flow rate of 3,000 liters per hour.

Production yields obtained with this culture system, when extrapolated to a one m3 tank, indicate that 50 g of brine shrimp cysts can be converted into 20 kg of fresh (wet dry) pre‐adult Artemia in 14 days. These results are comparable to those reported earlier with open flawthrough conditions.
Effects of Stocking Density, Salinity, and Light Intensity on Growth and Survival of Southern Flounder Paralichthys lethostigma Larvae
Authors: Daniels H. V. , Berlinsky D. L. , Hodson R. G. , Sullivan C. V.
Published: August 2010

Four separate studies were done on Southern flounder Paralichthys lethostigma larvae during first feeding and metamorphosis to determine the effects of stocking density, salinity, and light intensity on growth and survival. One study used stocking densities of 10, 20, 40, and 80 fish/L during first feeding; the second study compared the growth and survival of larvae stocked at 20 and 33 ppt; and a third experiment evaluated stocking densities of 1/L and 3/L under two different light intensities (1,600 lux vs 340 lux) during metamorphosis. The fourth experiment tested the effects of different salinities (0, 10, 20 and 30 ppt) on larval growth and survival during metamorphosis. Growth and survival (overall 6.9%) were not significantly different (P > 0.05) for stocking rates up to 80/L. Larvae placed into 20 ppt salinity had survival through first feeding similar to that of larvae raised at 33 ppt. During metamorphosis, light intensity had no effect (P > 0.05) on growth or survival, but fish stocked at 3/L had significantly lower (P < 0.05) survival than fish at 1/L. Complete mortality of larvae occurred at 0 ppt. Growth and survival past metamorphosis were not significantly different (P > 0.05) at 10, 20 and 30 ppt, but unmetamorphosed fish did not survive to day 60 at 10 ppt. Based on these results, practical larviculture of Southern flounder may require a two‐step process with high stocking rates (80 fish/L) through first feeding and lower densities (1/L) through metamorphosis. Fingerling production in fertilized nursery ponds might he possible at salinity as low as 20 ppt.
Sampling Shrimp Populations in Hatcheries
Authors: Juarez Lorenzo M. , Luxem Allan H. , Rouse David B.
Published: August 2010

Abstract.– Shrimp populations were estimated with volumetric sampling techniques during different phases of hatchery operations. Factors considered which might effect precision of estimates included stage age, density and temperature. Estimates of nauplii were obtained with coefficient of variation values smaller than 3% when nauplii were concentrated in 20‐L buckets and smaller than 8% when released in 13,000 L of water in larval rearing tanks. In both cases estimates were of sufficient precision to make management decisions for routine hatchery work. A technique was developed for estimating shrimp populations in larval rearing tanks with coefficient of variation values smaller than 15%. Volumetric sampling of postlarvae older than PL4, in larval rearing tanks was highly variable due to the tendency of shrimp to congregate and attach to tank walls and bottoms. A direct relationship was observed between postlarval density and the precision of population estimates in harvest buckets. Water temperature and postlarval age did not affect precision at the densities and ages studied. These findings have important implications for commercial transactions. Industry standards utilizing coefficient of variation are recommended for larvae and postlarvae population estimates.
Epitheliocystis Disease in Cultured Yellowtail Seriola mazatlana in Ecuador
Authors: Venizelos Arietta , Benetti Daniel D.
Published: August 2010

Abstract.– Epitheliocystis, a disease of the gill and skin epithelial cells, is reported in the early developmental stages of Pacific yellowtail Seriola mazatlana, a new marine finfish species for aquaculture in Ecuador. Behavior, appearance of infected larvae and clinical signs of infection are described. Light microscopic and histological examinations confirm the presence of intracellular organisms in the gills, skin, nostril and buccal cavity. Proliferative cell response resulted in the gradual destruction of the functional integrity of the gills, causing massive mortalities.
Effects of Feeding Time and Frequency on Growth of Channel Catfish Ictalurus punctatus in Closed Recirculating Raceway Systems
Authors: Jarboe Herman H. , Grant William J.
Published: August 2010

Abstract.– Experiments were conducted to evaluate the effects of feeding time and frequency on the growth, survival, feed conversion, and body composition of channel catfish Ictalurus punctatus cultured in closed recirculating raceway systems. In separate experiments, two stocking sizes (18 and 232 g/fish) of channel catfish were examined. Treatments consisted of 1) feeding catfish once daily, 3% of body weight at 0800 h; 2) feeding catfish once daily, 3% of body weight at 1200 h; 3) feeding catfish once daily, 3% of body weight at 1700 h; and 4) feeding catfish three times daily, 1% of body weight at 0800 h, 1200 h, and 1700 h. Weight gain, specific growth, feed conversion, percentage survival, and fillet proximate composition of channel catfish among treatments did not differ (P > 0.05). The percentage visceral fat of channel catfish fed the single meal at 0800 h was significantly lower (P < 0.05) than channel catfish receiving multiple feedings, but was not different than the visceral fat content of channel catfish fed at 1200 h and 1700 h. Under the conditions of this study, results indicate neither feeding time or feeding frequency significantly influences the growth, survival, and body composition of channel catfish raised in closed recirculating raceway systems.