bluuebunny/crossref_metadata_2025 huggingface dataset:
DIETS, EQUIPMENT, AND TECHNIQUES FOR MAINTAINING CRAWFISH IN THE LABORATORY
Authors: Tarshis I. B.
Published: August 2010

One commercial and 4 laboratory prepared extruded, water‐stable diets were fed 3 times a week in 1‐g portions to juvenile male and female White River crawfish, Procambarus acutus acutus (Girard), for 10 weeks. The binding material in the laboratory preparation was alginate (Kelgin), whereas that in the commercial preparation was starch.

No statistically significant weight differences developed between the groups of crawfish at the end of the 10‐week period; all 5 diets were found satisfactory for feeding and maintaining P. acutus acutus in the laboratory, and all test crawfish survived throughout the experimental period. Weight gains were highest in a diet containing 50.5% protein; intermediate in those fed a diet with 46.0% protein; and lowest in those fed diets with 31.7 or 36.3% protein. Crawfish fed the commercial preparation of one of the 46.0% protein diets showed a slightly but not significantly higher weight gain than those fed the laboratory preparation of the diet.

In an evaluation of the water stability of 5 commercially prepared animal chow diets and the commercial extruded diet, 2 of the commercial diets disintegrated after one hour exposure in water and the other 3 became bloated after one hour and remained on the surface throughout the 24‐hour test. The commercial extruded diet maintained its water stability for the full 24 hours.

The commercial preparation of the 46.0% protein diet was successfully used under laboratory conditions for feeding and maintaining the following crawfishes: Cambarellus shufeldtii (Faxon), Cambarus acuminatus Faxon, Orconectes limosus (Rafinesque), O. virilis (Hagen), Procambarus clarkii (Girard), and P. spiculifer (Le Conte). In longevity experiments Cambarus diogenes diogenes Girard and Procambarus hinei (Ortmann) now have survived for 8 months on this diet in the laboratory.
AN EVALUATION OF THREE SPECIES OF DIATOMS AS FOOD FOR Cancer magister LARVAE1
Authors: Hartman M. C. , Letterman G. R.
Published: August 2010

Diets consisting only of the diatoms Skeletonema costatum, Thalas‐siosira pseudonana and Phaeodactylum tricornutum were tested on Cancer magister larvae. Each algal species was fed singly and in combination with the others. Unfed controls died after 10 days without molting to the second stage. Those larvae receiving P. tricornutum lived only slightly longer than the starved animals and none reached second stage. S. costatum and T. pseudonana fed singly sustained the larvae 40 and 48 days and allowed development to the third and fourth stages respectively. Survival to 57 days and development into the fifth stage was reached on a diet consisting of a mixture of S. costatum and T. pseudonana. Mixing P. tricornutum with either of the other species did not improve survival beyond those used singly, and mixture of all 3 species was less beneficial than the best 2‐part diet.
CONDITIONING FLORIDA POMPANO (Trachinotus carolinus) FOR CONTINUOUS SPAWNING
Authors: Hoff F. H. , Pulver T. , Mountain J.
Published: August 2010

A series of 3 temperature and light conditioning experiments was conducted on pompano during the fall and winter of 1971 and 1972 to stimulate gonadal development to a prespawning condition during non‐breeding seasons. Two experimental parameters were designed from field data and compressed to 5:1, or 3:l (normal to experimental day). A third experiment used constant temperature/light regime. Gonadal development was checked routinely by in vivo sampling. Use of habitat to stimulate more natural conditions neither enhanced or deterred gonadal development. In changing regimes, 50% or more individuals were in prespawning condition by the 11th or 12th week. While under constant conditions 11 to 45% were ready at each sampling. Food consumption in regard to habitat and temperature was considered. Disease, infections and injuries usually occurred during, or just after, the colder portion of the regime and/or during periods of low pH.
WET AND DRY SEASON COMPARISON OF Tilapid aurea PRODUCTION IN EL SALVADOR IN NEW FERTILIZED AND UNFERTILIZED EARTHEN PONDS
Authors: Ledgerwood R. D. , Hughes D. G. , Ortiz M. Vargas
Published: August 2010

Two 14‐week fertilization experiments were conducted in newly constructed earthen ponds on the tropical coastal plain of El Salvador. A combination of 0–20‐0 plus chicken manure applied during the dry season produced a higher biomass (5853 net kg/ha per year) of the phytoplanktivorous fish Tilapia aurea than did 20‐20‐0, 0–20‐0, or chicken manure alone (4643, 4977, and 2486 net kg/ha per year, respectively). All treatments including an inorganic fertilizer were significantly more productive than treatments receiving only chicken manure. Ponds receiving chicken manure alone were twice as productive as unfertilized control ponds, which had an average net production of 1240 kg/ha per year. The inclusion of nitrogen in the inorganic formulas did not enhance fish production; rather, it appeared that phosphorus was the limiting factor.

Four application levels of the 0–20‐0 plus chicken manure fertilizer were tested during the wet season against unfertilized control ponds. The net production of fertilized ponds ranged from 3031 to 4454 kg/ha per year. Control pond net production averaged only 870 kg/ha per year, a drop from dry season production of 30%. The fertilizer applied during the wet season produced 48% less net fish production than the same fertilizer applied at a similar rate in the dry season. Increased turbidity from bank erosion following heavy rains appeared to limit wet season fish production. The 0‐20‐0 plus chicken manure fertilizer combination during the dry season produced higher net earnings ($1285/ha per year) than any other treatment.
IMPLICATIONS OF GROWTH AND METABOLIC RATES ON COSTS OF AQUACULTURE1
Authors: Botsford L. W. , Gossard T. W.
Published: August 2010

In aquaculture research, proposals to improve performance of the cultured organism usually involve increasing growth rate, decreasing food conversion ratio, or changing some other measure through research. Common to most proposals is an attempt to manipulate the organism's growth and metabolic rates. We develop a general approach to aquaculture research that leads to the greatest reduction in culture costs for the least expenditure in research costs. Using an existing mathematical model of lobster culture as an example, the effect on culture and research costs of changes in growth and metabolic rates are evaluated. The optimal relative changes in growth and metabolic rates depend on the current values of these rates as well as relative costs of culture system components. The optimal change in both growth and metabolic rates is better than maximizing or minimizing any single performance criterion (e.g., food conversion ratio). The optimal path differs between extensive and intensive culture systems and has implications for species selection.
SUSPECTED BLUE‐GREEN ALGAL POISONING IN THE BLUE SHRIMP
Authors: Lightner D. V. , Danald D. A. , Redman R. M. , Brand C. , Salser B. R. , Rerpieta J.
Published: August 2010

Blooms of a marine blue‐green alga, Spirulina subsalsa, were found to cause a particular disease syndrome, called hemocytic enteritis, in tank or raceway‐reared blue shrimp (Penaeus stylirostris). The disease was characterized by necrosis of the lining epithelium of the midgut and occasionally of the dorsal caecum and hindgut gland. Bacterial infections, due predominantly to Vibrio alginolyticus, were common in affected shrimp and were presumed to be a secondary condition resulting from necrosis of the gut epithelium. Intestinal lesions were induced in blue shrimp fed living cultures of S. subsalsa sp. as a diet supplement, but not in shrimp fed fresh cultures of other algal forms (Oscillatoria sp. and Nitzchia sp.) indigenous to the shrimp culture tank and raceways. Blue shrimp reared in tanks in which S. subsalsa was the dominant algal form showed reduced growth rates, reduced biomass, and reduced survival compared to shrimp reared in tanks in which Enteromorpha sp. and various diatom species were dominant.

Recent findings indicate that blooms of certain Oscillatoria sp. and possibly other blue‐green species may also produce the syndrome in tank or raceway‐reared blue shrimp.
SPACE, DENSITY AND GROWTH OF THE LOBSTER (Homarus americanus)
Authors: Aiken D. E. , Waddy S. L.
Published: August 2010

Area required for unrestricted growth of large juvenile lobsters held individually is estimated at 75 times carapace length squared, or 75 (CL)2. Growth of lobsters held individually in 55 (CL)2 was compared to growth in 18 (CL)2, and to growth of lobsters in communal tanks of equivalent size and stocking density.

In 55 (CL)2, length increase averaged 14.3%, vs 10.3% for 18 (CL)2. Increases in communal tanks were comparable, indicating space and density have similar impact on linear increase.

For lobsters between 60 and 80 mm carapace length, maximum stocking density was estimated at 1.0 kg/m2. Injury was negligible in the communal tanks at 0.9 kg/m2, but excessive at 2.5 kg/m2. Cheliped immobilization reduces undesirable effects of communal holding provided recommended stocking density is maintained.
THE EFFECTS OF CONTAINER SIZE AND TRANSPARENCY ON GROWTH AND SURVIVAL OF LOBSTERS CULTURED INDIVIDUALLY1
Authors: Van Olst J. C. , Carlberg J. M.
Published: August 2010

The high rates of cannibalism observed in American lobsters (Homarus americanus) held in communal rearing systems dictate that for a majority of the culture period the animals must be held individually in order to prevent these losses. An experiment was conducted to assess the dependence of growth rate, molting frequency, and survival on the amount of horizontal surface area provided for each lobster. Eight sizes of individual containers ranging from 6 to 750 cm2 were provided. Parallel experiments were conducted in containers made of both transparent and translucent materials so that the effects of visual communication also could be determined.

The experiments have been in progress for 24 months. Growth and survival have been severely reduced in the smaller rearing containers. Molting frequency was not as severely affected. No significant differences in growth were found between lobsters in visual contact and visual isolation. Equations describing the relationship between space and growth are presented and estimates are made of the effects of space requirements on the design of a commercial lobster culture facility.
EXPERIMENTAL CULTURE OF Mytilis edulis (L.) IN A NORTHERN ESTUARINE GRADIENT: GROWTH, SURVIVAL, AND RECRUITMENT
Authors: Incze L. S. , Porter B. , Lutz R. A.
Published: August 2010

Mussels (Mytilus edulis L.) were experimentally cultured at 12 sites (1.5 km intervals) in an estuarine gradient on the Damariscotta River, Maine. Growth, survival, and recruitment of mussels were monitored and hydrographic data were collected. Peak growth of mussels occurred in May and June. The 4 upper‐estuarine sites were characterized by (1) earlier timing of peak growth, (2) suppressed growth in June and July relative to lower estuary mussels, and (3) marked mortality in September. Mussels grew rapidly in the lower 10 km of the estuary, exhibiting different temporal patterns of growth, but achieving comparable seasonal growth and survival. Seed mussels used for the growth experiments had settled on collectors during the previous summer and, accordingly, grew to 50 mm length in approximately 12 months: 15 months of growth yielded 57–71 mm mussels. Recruitment varied considerably, but was consistently high throughout the middle estuary, where settlement densities of 5–8 seed mussels per cm2 were observed. A 5‐year record of spatfall at one site in the middle estuary indicated that recruitment there was relatively consistent from year to year. The high mortality of mussels in the upper estuary of the Damariscotta River was associated with temperatures of 20°C and above, but may be related to factors other than temperature stress per s***a. Reduced ration during periods of warm temperature and increased metabolism may be responsible for these mortalities. Dense populations of newly‐settled mussels survived at some locations where temperatures exceeded 20°C and adult mortalities were high, indicating that high settlement densities and the existence of extensive populations of very young mussels do not, by themselves, provide enough information to adequately assess the potential of a site for mussel aquaculture. This potential may be meaningfully assessed by the use of a small experimental mussel raft and the collection of temperature and salinity data. Our results indicate that extensive areas of estuaries similar to the Damariscotta may be utilized for the culture of mussels.
CHEMICAL CONTROL OF REPRODUCTION IN BIVALVE AND GASTROPOD MOLLUSCS, III:AN INEXPENSIVE TECHNIQUE FOR MARICULTURE OF MANY SPECIES
Authors: Morse D. E. , Hooker N. , Morse A.
Published: August 2010

The addition of hydrogen peroxide to alkaline seawater provides an inexpensive, simple, and reliable method for the control and synchronous induction of broadcast spawning in males and females of certain bivalve and gastropod molluscs. Species successfully induced by this method thus far include:abalones (Haliotis rufescens, H. corrugata, and H. fulgens), mussels (Mytilus edulis and M. californianus), purple‐hinged rock scallop (Hinnites giganteus) and the mangrove oyster (Crassostrea rhizophora). Enzymological and physiological studies indicate that spawning may result from a peroxide‐induced stimulation of the endogenous enzymatic synthesis of potent hormone‐like prostaglandin molecules. Peroxide‐stimulated prostaglandin synthetase also has been found in reproductive tissues of certain crabs and fishes, thus indicating potential applicability of this method for the control of reproduction in higher species. However, internally fertilized gastropods, such as the queen conch (Strombus gigas), show no induction of reproductive behavior or egg‐laying (after mating) upon exposure to H2o2.
CHANGES IN LIPID AND STEROL LEVELS AS OYSTERS Crassostrea virginica (GMELIN) APPROACH MARKET SIZE
Authors: Krishnamoorthy R. V. , Venkataramiah A. , Lakshmi G. J. , Biesiot P.
Published: August 2010

A detailed study of the lipid and sterol contents of “lean” oysters (Crassostrea virginica) was made to determine changes in relation to size and sex as the oysters approached marketable size. The growth of oysters was assessed by shell length and meat weight relationships which are non‐linear and sex‐dependent. The lipid content of the meat was directly related to size on a logarithmic scale and was independent of sex. The relationship between total sterol content and the weight of oyster meat was non‐linear and followed a fifth‐degree polynomial function with the total sterol level decreasing with growth. The polynomial parameters were different in relation to sex with adult males showing a higher sterol content than females. Based on these models, it was determined that oysters with an 8 to 10 g meat weight or 95–100 mm shell length have low sterol and triglyceride levels. This correlates fairly closely to the minimum legal size of oysters which is 3‐1/2 inches (89 mm).
EFFICACY OF QUINALDINE AND MS‐222 ON AMERICAN EEL
Authors: Hinton M. J. , Loyacano H. A.
Published: August 2010

Quinaldine and tricaine methanesulfonate (MS‐222) were tested on glass eel and elver stages of American eel (Anguilla rostrata) over periods of 24 and 48 hours at 22 to 22.5°C in soft, reconstituted fresh water. Three concentrations of each anesthetic were tested with 10 eels/ treatment. At the end of the testing period the eels were placed in fresh water and their recovery times noted. MS‐222 was tested at concentrations of 35, 45, and 55 ppm with glass eels. Glass eels in 45 ppm reached stage II within 22 min and remained in this condition throughout the tests. Recovery time for both the 24 and 48‐hour tests was immediate. Two eels in 55 ppm died during the 24‐hour tests and 5 eels died during the 48‐hour test. Concentrations used with elvers were 40, 50, and 55 ppm. Elvers in 55 ppm reached stage II within 30 min. At 24 hours 4 eels remained in stage II condition and one had died. The survivors recovered immediately. At 40 hours 2 eels remained in stage II condition and one had died. The survivors recovered immediately. Quinaldine was tested at concentrations of 15, 20, and 25 ppm with glass eels. These concentrations anesthetized the glass eels to stage II condition within 16 min but were fatal to all eels within 12 hours. Concentrations used with elvers were 8, 10, and 12 ppm. Five elvers in 12 ppm reached stage II within 50 min and at 12 hours all elvers were in stage II condition. At 24 hours 4 elvers were in stage II condition and had a 5 min 20 sec recovery time. This concentration was fatal to all eels within 48 hours.
AN OVERVIEW OF AQUACULTURE RESEARCH IN THE SOUTHEAST FISHERIES CENTER'S GALVESTON LABORATORY1
Authors: Klima E. F.
Published: August 2010

The Aquaculture Program at the Galveston Laboratory of the National Marine Fisheries Service's Southeast Fisheries Center is divided into 2 phases, experimental and demonstration. The experimental phase includes maturation and reproduction, grow‐out and economical and biological evaluation. Positive economic and biological evaluation in the experimental phase will lead to phase 2, the demonstration of a pilot operation. Successful completion of the demonstration phase, which will be conducted in cooperation with industry, will eventually lead to commercial rearing of marine animals for either food, bait or seeding of wild stocks. The major thrust of this program has been to rear shrimp for bait, a research investment warranted by the demand for bait shrimp and prospects for success. Results to date indicate that shrimp can be reared in closed systems to a size suitable for sale in the northern Gulf of Mexico as bait shrimp. In addition, studies are being conducted to culture marine sea turtles, specifically loggerhead, and release the cultured juveniles into the wild in an attempt to increase wild populations of depleted, threatened or endangered species. Further, studies have been successful in rearing finfish in closed systems, and future work will be concentrated on the rearing of striped bass, redfish, and snapper for release in the marine environment as juveniles in an attempt to increase or augment wild populations.
CULTURING THE AMERICAN LOBSTER (Homarus americanus) USING A VERTICALLY STACKED CAGE SYSTEM1
Authors: Mickelsen R. W. , Infanger R. C. , Heckmann R. A.
Published: August 2010

A vertically stacked cage system capable of supporting juveniles and adult lobsters in individual compartments has been designed and is being tested for commercial production of the American lobster Homarus americanus. Details are given for the construction and operation of the unit as well as techniques for feeding each animal. The modular unit is designed for lobsters ranging from the 4th stage to the adult size.
EFFECTS OF STOCKING DENSITY AND SUBSTRATE ON GROWTH AND SURVIVAL OF CRAWFISH (Procambarus clarkii) GROWN IN A RECIRCULATING CULTURE SYSTEM1
Authors: Goyert J. C. , Avault J. W.
Published: August 2010

The growth and survival of crawfish (Procambarus clarkii) raised in a recirculating water system at 2 stocking densities (10/m2 and 40/m2) and 3 substrate configurations (surface area, hiding place and control) is described. Crawfish grown in the control and hiding place substrates grew larger at the high density (3.9 mm and 8.9 nun, respectively) than those at the low density. At a density of 40/m2. a shift from antagonistic to passive behavior among crawfish is theorized for explaining the higher growth. Crawfish raised with the surface area substrate exhibited the best growth and survival regardless of stocking density. Further research is recommended to determine the minimum spatial requirements for crawfish growth and the maximum carrying capacity of surface area type substrates.
THE DESIGN OF A NEW HIGH RATE NITRIFICATION FILTER FOR AQUACULTURE WATER REUSE
Authors: Brune D. E. , Gunther D. C.
Published: August 2010

A new design in a high rate nitrification system has been tested at the laboratory scale. Ammonia removal rates per unit of filter volume at influent ammonia levels of 0.02 mg NH3‐N were observed to be 5 to 10 times more rapid than rates observed in conventional field‐scale nitrification filters. At these levels 95 to 99% ammonia removal has been achieved with filter detention times as short as 3 minutes. The data are compared to data for various field units and the reasons for the observed high removal rates are discussed. The possibility of retaining these high efficiencies in scaled‐up filters is also discussed.
ION EXCHANGE SYSTEMS FOR WATER RECIRCULATION
Authors: Liao Paul B. , Kramer S. S. Lin
Published: August 2010

Since the Bozeman Study in 1972, several pilot plants have been investigated to evaluate the application of the ion exchange systems for water recirculation in fish hatcheries. Pioneering work was made at the biological research laboratory of Kramer, Chin and Mayo, Inc., followed by a pilot plant testing at the Oregon Aqua Fish Hatchery in Newport, Oregon. In 1976, two 50‐gallon per minute capacity ion exchange bed systems were installed and tested at Dworshak National Fish Hatchery in Orofino, Idaho. Recently, water reuse is accomplished by pumping approximately 120 gallons per minute from the raceway and filtering it through the pressure sand filter and the clinoptilolite filters for the removal of ammonia in the Seattle Aquarium.

The paper will discuss the physical and chemical properties of ion exchange materials, pilot plant test results, engineering design criteria and application, and economics as compared to conventional biological ammonia removal systems. In addition, discussion will also be made in the area of pretreatment prior to ion exchange bed and regeneration as well as operational procedure adjustment. Further works needed to be conducted to provide optimum operating conditions will be discussed.
PRELIMINARY EVALUATION OF SURVIVAL AND GROWTH OF JUVENILE RED DRUM (Sciaenops ocellata) IN FRESH AND SALT WATER
Authors: Crocker Philip A. , Arnold Connie R. , Holt Joan D. , DeBoer James A.
Published: August 2010

Heretofore few quantitative studies on the tolerance of red drum (Sciaenops ocellata Linnaeus) to freshwater (FW) or dilute sea water have been conducted. In the laboratory we subjected larval and juvenile stages of red drum to dechlorinated FW for 96 hours and found 5% survival in larvae (23‐day‐old, 6.2 mm SL), 70% for postlarvae (34 and 47‐day‐old, 16.2 mm to 19.7 mm SL) and 95% for juveniles (57‐day‐old, 56.9 mm SL). Survival in control salinities of 10 ppt was 90% or greater. The results indicate that tolerance to dilute media is size dependent.

In a separate experiment growth of juvenile red drum (52 mm SL) over a 30‐day period was compared in two raceways with flow‐through supplies of dechlorinated FW, and SW of ambient (35±2 ppt) salinity. SW fish grew significantly larger (P < .01) than those acclimated to FW. Within both treatments a large size differential developed with time. Food conversion efficiency was improved and appetite drive was enhanced in the SW treatment. Percent survival after 30 days was comparably high (93%) in both treatments.

Fast growth and high survival of juvenile (>20 mm SL) red drum promote the feasibility of this valuable sport and commercial species in both FW and SW aquaculture. Its potential as a control fish in FW fishery management deserves further investigation.
MATURATION, REPRODUCTION, AND GROWTH OF Penaeus vannamei AND P. stylirostris FED NATURAL DIETS
Authors: Chamberlain George W. , Lawrence Addison L.
Published: August 2010

A variety of natural foods have been reported to induce ovarian maturation of penaeid shrimp. In this study, conducted from 19 June to 11 September 1980, four single‐food diets (clams, shrimp, squid, and worms) and one composite diet consisting of all four foods were fed to Penaeus vannamei in 3.7‐m diameter indoor circular tanks. The shrimp, averaging 28 g, were stocked at a rate of 6.9 m‐2 with a 1:1 male to female ratio. Unilateral eyestalk ablation was performed on half of the females in each tank. Tanks received one turnover of water volume daily and the water temperature and salinity averaged 27.0°C and 28.6 ppt, respectively. Daily photoperiod was maintained at 13 hours of light. Ovarian maturation, spawning, molting rate, and survival were monitored daily and growth and gonad size were measured at termination. The composite diet was the best overall diet, while squid was the best single‐food diet, followed by shrimp, worms, and clams. No maturation of unablated females was observed with the exception of one female that developed to stage 3. Although the size of the shrimp was considered marginal for spawning, 5 mated females were observed, but only one (squid treatment) produced viable nauplii. After termination of this study, all shrimp were fed the composite diet for 41 days. During this period, ovarian maturation and spawning occurred in the previously unproductive treatment receiving only clams, and growth rate of shrimp in all previously single‐food treatments increased 4 to 7 fold. The composite diet was also fed to two tanks of P. stylirostris (mean initial weight = 45.4 g) for a period of 118 days. During that time, 50 spawns were obtained with up to 3 spawns per female. A total of 4.3 × 105 P. stylirostris nauplii were produced.
THE EFFECTS OF FATTY ACID AND SHRIMP MEAL COMPOSITION OF PREPARED DIETS ON GROWTH OF JUVENILE SHRIMP, Penaeus stylirostris
Authors: Fenucci Jorge L. , Lawrence Addison L. , Zein‐Eldin Zoula P.
Published: August 2010

Pelletized diets containing different amounts of sun‐dried shrimp meal and brewer's yeast were tested. A relationship was observed between the content of shrimp meal and brewer's yeast in the diets and increased growth of juvenile shrimp, Penaeus stylirostris. Data suggested that in feeds containing 5% squid meal, up to half the shrimp meal can be replaced by brewer's yeast. These feeds should thus contain at least 15% shrimp meal and less than 15% brewer's yeast. A quadratic correlation was found between the rate of growth of juvenile shrimp and the percentage of linoleic acid in the diets. The best nutritional response should be obtained in rations containing 14.5% linoleic acid. The same type of relation was observed for the ratio of the linolenic series (ω3)/linoleic acid (106) with the ratio of 1.18 giving the best nutritional response for the diets tested in this study.
MARINE AQUACULTURE IN DENMARK
Authors: Hoffmann Erik
Published: August 2010

During the last five years marine aquaculture has developed rapidly in Denmark. Today the following species are used in mariculture either in laboratory scale or in commercial farms (underlined): Rainbow trout (Salmo gairdneri), turbot (Scophthalmus maximus), eel (Anguilla anguilla), lobster (Homarus vulgaris), the European flat oyster (Ostrea edulis), Pacific oyster (Crassostrea gigas) and blue mussel (Mytilus edulis).

The marine production of rainbow trout in 1981 was approximately 405 tonnes with an expected rise to about 500 tonnes in 1982. Problems with Vibriosis and Furunculosis have occurred. A method of vaccination against Vibriosis by spray‐pistol has given promising results. Several new types of net cages have been constructed using a combination of traditional floating net‐cages and pound net poles placed in the sea bottom.

Hatching and rearing of turbot and lobster have been successfully accomplished on a laboratory scale. Today turbot are found in two experimental fish farms which utilize heated effluent from power plants.

The oyster Ostrea edulis has been extensively cultivated in the Limfjord area for about 100 years. The yearly production has varied between 100,000 and 4 million individuals with the lowest values in recent years. In 1978 Crassostrea gigas was introduced in Denmark. Culture beds for blue mussel have been established but at present the production cannot be estimated.
PRODUCTION, CHEMICAL QUALITY AND USE OF DUCKWEEDS (LEMNACEAE) IN AQUACULTURE, WASTE MANAGEMENT, AND ANIMAL FEEDS
Authors: Culley Dudley D. , Rejmánková Eliska , Květ Jan , Frye J. B.
Published: August 2010

The vascular plants known as duckweeds have been the subject of intense interest during the past decade as an aquacultural crop, part of waste management systems, and as a feed supplement for aquatic and terrestrial animal stocks. Yields in high nutrient lagoons in regions with nine‐month growing season average about 10 metric tons (dry)/hectare, with maximum yields of 12 metric tons projected from .04 hectare lagoons. Crude protein for duckweeds cultured on animal waste lagoons has ranged from 35 to 45% of the dry weight and all essential amino acids are present. Lysine is present in sufficient concentration to meet FAO reference standards for animal feeds, and methionine equals or exceeds recommended standards in specific clones of Lemna turionifera, L. minor, and Spirodela polyrrhiza. Minerals, fat, fiber, and carbohydrate levels are not excessive for most animal diets. Successful feeding trials have been conducted with several species of fish, ducks, swine, poultry, and cattle. A review of research indicates this family of plants holds high promise for producing high quality animal and human food world‐wide, but the technology for controlled production under full‐scale systems is incomplete.
THE TIME‐OF‐DAY GOLDFISH RECEIVE A SINGLE DAILY MEAL AFFECTS GROWTH
Authors: Noeske Teresa A. , Erickson David A. , Spieler Richard E.
Published: August 2010

Six groups of goldfish, held on a 12L:12D photoperiod and 10°C, had access to food once daily at one of six different times of day. Appetite, somatic growth (weight and length), condition, and gonadal growth (females only) differed among the groups depending on the time‐of‐day of feeding.
POND REARING TRIALS WITH MALAYSIAN PRAWNS, Macrobrachium rosenbergii, BY PRIVATE GROWERS IN SOUTH CAROLINAl 19811
Authors: Smith Theodore I. J. , Sandifer Paul A. , Jenkins Wallace E. , Stokes Alvin D. , Murray Glenn
Published: August 2010

During 1981, pond culture trials with prawns, Macrobrachium rosenbergii, were conducted with 7 private farmers in order to obtain information on the potential for prawn farming in South Carolina. Some farmers were able to control water quality while other farmers had little or no ability to modify pond environmental conditions. Seed stock, feed, management, and harvesting assistance were provided by research personnel, while daily monitoring of pond conditions and feeding were the responsibility of the farmers.

Eight ponds (size range 0.04‐0.41 ha) were stocked with small juvenile prawns (mean weight 0.29 g) at densities of 4.3/m2 (43,000/ha) or 6.5/m2 (65,000/ha). An additional pond, containing hung webbing to increase habitat area, was used in a high density rearing trial and stocked at a density of 19.5/m2. Growing periods ranged from 125 to 173 days during which time most farmers encountered some serious problems (predators, competitors, low dissolved oxygen levels, etc.). In the lower density trials (4.3 and 6.5/m2) production averaged 573 kg/ha (range 155–900 kg/ha) while survival averaged 44.2% (range 13.4–67.9%). Feed conversions ranged from 1.84 to 7.40 and averaged 3.34. The high density trial resulted in a production rate of 1,902 kg/ha, a survival rate of 51.2%, and a feed conversion of 2.4.

Disposition of the prawn crops included: 1) direct sales to customers; 2) marketing through a farmer‐owned restaurant; and 3) retention of a portion or all of the production to substitute for the purchase of marine shrimp. Direct sales to consumers offers a number of advantages and may be the most suitable market for the predicted near‐term level of production.
EFFECTS OF FEEDING RATE AND FEEDING FREQUENCY ON PROTEIN DIGESTIBILITY IN THE FRESHWATER SHRIMP (Macrobrachium rosenbergii)
Authors: Taechanuruk Suchat , Stickney Robert R.
Published: August 2010

Neither feeding rate nor feeding frequency appear to affect protein digestibility in the freshwater shrimp,Macrobrachium rosenbergii. A feeding frequency of twice daily resulted in a significant increase in food consumption compared to feeding once or 3 times daily. Apparent protein digestibility from a diet containing menhaden meal as the primary protein source ranged from 83.3% to 87.7% based on the chromic oxide method. Those values were within the ranges published on other crustacean species for fish meal and other proteins.
COMPARISON OF FRESHWATER PRAWN FARMING IN HAWAII AND IN THAILAND: CULTURE PRACTICES AND ECONOMICS
Authors: Shang Yung C.
Published: August 2010

Freshwater prawn Farming in Thailand is relatively extensive, i.e., with low stocking rate and low yield, as compared to Hawaii. However, the cost of production per kg of marketable prawns is comparatively low due to inexpensive inputs. The low costs of production and current high price of prawn in Thailand resulted in a high profit. In Hawaii, despite the high yield, the profitability of prawn Farming is low at the present time because of the high costs of production.
GROWTH OF HYBRID TILAPIA FRY FED NITROGEN FIXING MARINE BLUE‐GREEN ALGAE IN SEAWATER
Authors: Murray Robert L. , Mitsui Akira
Published: August 2010

Ninety‐one strains of nitrogen fixing marine blue‐green algae were tested for their nutritional value for seawater adapted hybrid tilapia fry (Tilapia mossambica females x Tilapia hornorum males) with initial weights of 0.2 to 1.3 g. The majority of these blue‐green algae were acceptable single ingredient feeds for the fish when the increase in wet body weight was used as a measure of food value. Twenty‐two of the marine blue‐green algal strains tested, belonging to the genera Nostoc, Anabaena and Calothrix, supported daily weight gains in excess of 10% when the fish were fed to excess in 5 to 7 day feeding trials. Fish fed to excess on several selected blue‐green algal strains had growth rates equivalent to those of fish fed to excess on a complete ration. Excellent food conversion ratios (dry weight blue‐green algae fed/wet weight gain) in the range of 1.48 to 1.81 were obtained when the fish were fed three selected nutritive blue‐green algal strains at a daily rate of 10% of the body weight.
POPULATION DENSITY EFFECTS ON THE BEHAVIOR AND FEEDING OF YOUNG STRIPED MULLET (Mugil cephalus) IN 37.8‐LITER AQUARIA
Authors: Carr Barbara A. , Aldrich David V.
Published: August 2010

The swimming and feeding behavior of striped mullet (Mugil cephalus), 40–60 mm SL, was observed in 37.8‐liter aquaria. Five of the most frequently observed behavioral acts were then chosen as representatives of “normally” occurring behavior under these experimental conditions. These behavioral acts were subsequently counted in the 37.8‐liter aquaria with population densities of 3, 6, 18, 30 and 60 mullet per aquaria, during swimming and feeding observations. More food bites were taken at densities of 18 and 30 than at the other densities. Mullet kept at a density of 30 per tank exhibited the lowest mean number of long traverses (a distance of more than one‐half the aquarium front). Perhaps at a density of 30 mullet per aquarium (0.79 mullet/liter or 231 mullet/m2), food was assimilated into biomass and less was burned for energy. Obtaining data in aquaria in this manner may prove an invaluable tool since it is less expensive than stocking ponds experimentally and can provide a useful basis for deciding efficient stocking densities for any size fish.
THE EFFECT OF FISH ON PHYTOPLANKTON GROWTH IN OUTDOOR TANKS
Authors: Ogle John T. , Beaugez Kathleen A.
Published: August 2010

The presence of mullet in 4,000‐liter tanks used for rearing bull innows (Fundulus grandis) was noted to promote and prolong algal blooms compared to tanks of bull minnows containing no mullet. In separate studies utilizing 4‐liter cultures, algal concentrations were noted to be an average of 3 times as dense in containers with mullet as opposed to cultures with either no fish present or bull minnows present. Algal concentrations for all treatments were an average of 2 times denser for treatments that were fed as opposed to those that received no food.
ASSIMILATION OF NUTRIENTS BY CULTURED HYBRID LOBSTERS (Homarussp.) FED EXPERIMENTAL DIETS1
Authors: Bordner Clark E. , D'Abramo Louis R. , Conklin Douglas E.
Published: August 2010

Indirect calorimetry and the chromic oxide indicator method were employed to investigate the digestibility and assimilation of nutrients by cultured lobsters (Homarussp.) growing on experimental diets. Starved and fed lobsters were compared by observing food and oxygen consumption and fecal and urinary excretions in a closed, recirculating metabolic chamber. Apparent digestible and metabolizable energy and nitrogen were determined for 2 diets, which differed in the type and level of protein and carbohydrate. The apparent digestibility of diet 79F, a purified ration containing 46.8% crude protein, was 68.8% on an as‐fed basis, with an apparent digestibility of energy of 88.1%. For diet SM25B, which contained 61.1% crude protein including shrimp meal, apparent digestibility was 66.2% as‐fed and the apparent digestibility of energy was 91.3%. Metabolizable energy values of 4.59 and 4.65 kcal/g dry weight were obtained for diets 79F and SM25B respectively. Growth on the two diets was similar but lobsters fed 79F consumed and excreted significantly more than those fed SM25B. For both diets protein and lipid were better than 90% digested, but the carbohydrate fraction was only about 65% digestible. The apparent higher nutritive value of SM25B for lobsters may be related to protein quality and improved efficiency of utilization.
SURVIVAL AND GROWTH OF Penaeus setiferus L. AND Penaeus aztecus IVES LARVAE FED Artemia BEGINNING AT THE PROTOZOEA‐TWO SUBSTAGE VERSUS THE MYSIS‐ONE SUBSTAGE
Authors: Kuban Frank D. , Wilkenfeld Joshua S. , Lawrence Addison L.
Published: August 2010

The following experiments compared survival and growth of shrimp larvae fed Artemia nauplii beginning at either the protozoea 2, protozoea 3 or mysis 1 substage. Experiment one compared survival and growth of larval Penaeus setiferus, from the protozoea 2 substage to three‐day‐old postlarvae, fed algae and either freshly hatched Artemia nauplii, decapsulated Artemia cysts or ultraviolet killed Artemia nauplii beginning at the protozoea 2 or mysis 1 substage. Survival was better for those postlarvae fed all three Artemia food types beginning at the protozoea 2 rather than the mysis 1 substage. Post‐larval dry weights were similar, regardless of Artemia food type or the larval substage at which Artemia was introduced.

Experiment two compared survival and growth of larval P. aztecus, from the protozoea 2 substage to two‐day‐old postlarvae, fed algae and live Artemia nauplii beginning at either the protozoea 2, protozoea 3 or mysis 1 substage. Controls were only fed algae. Survival was significantly better for those postlarvae fed Artemia beginning at the protozoea 2 substage. Post‐larval dry weights increased with the introduction of Artemia nauplii beginning at the protozoea 2 substage. The potential effects of these results on current hatchery procedures are discussed.
EXPERIMENTS ON LARVAL REARING OF THE CALIFORNIA MUSSEL (Mytilus californianus)
Authors: Trevelyan George A. , Chang Ernest S.
Published: August 2010

Spawning, larval rearing, and settlement of Mytilus californianus were performed over a one‐year period at the University of California, Bodega Marine Laboratory in northern California. A combination of shell scraping followed by a 30 to 60 min immersion in 30 or 60 mM hydrogen peroxide was the most successful spawning stimulus tested. Larvae fed a diet of Isochrysis galbana grew significantly faster than did larvae fed Dunaliella sp. Larval growth rate was significantly more rapid at 20°C than at either 14 or 17°C and no significant differences in mortality rates between these three temperatures were detected. At 17 and 20°C, larvae fed a diet of 80 Isochrysis cells/μ1 daily grew significantly faster than those fed 20 Isochrysis cells/μ1 daily. Mortality of pedi‐veligers was high, but survivors settled and metamorphosed on byssal threads cut from adult M. californianus. Plantigrades had a mean growth rate of 7.8 μm/day between days 15 and 33 following settlement. In this study, a temperature of 20°C, a diet of Isochrysis galbana of at least 80 cells/μ1 daily, and a settlement substrate of byssal threads were the most successful conditions for artificial spat production of this potentially valuable bivalve mollusc.
JAPANESE ABALONE CULTURE PRACTICES AND ESTIMATED COSTS OF JUVENILE PRODUCTION IN THE USA
Authors: McCormick Thomas B. , Hahn Kirk O.
Published: August 2010

Approximately 100 species of abalone are known to exist in the world and commercial abalone fisheries have been established in at least 6 countries. In Japan, 5 species of abalone provide an annual catch of 5,000 metric tons (whole weight with shell) which sells for 6,000/kg (US$27/kg). To increase productivity of coastal waters, juvenile abalone “seed” (10–30 mm) are produced at government operated Fish Farming Centers. Production has increased from 200,000 seed in 1970 to more than 10.7 million in 1978. Survival of artificially reared abalone from larvae to 20 mm averages 1%. Problems still exist in providing the quality and quantity of food required by postlarvae and older juvenile abalone. Twenty millimeter seed is sold by the farming centers to fishermen at a price of $0.10‐0.12 each, which represents only 1/2 to 1/4 of the production costs. Seed is placed in coastal waters for grow‐out to 11–12 cm in 3–5 years. Recapture rates may exceed 10%. Production costs at the only private abalone hatchery in Japan are estimated to be $0.018/mm of shell length. Based on Japanese methods for seed production, an assessment of production costs for an abalone hatchery in the USA is presented. With an annual production of one million abalone (20 mm each) the production cost is estimated to be $0.022/mm of shell length or $0.44/20 mm abalone. The success of abalone production in the USA will be determined by cost effective hatcheries and a strong market for the abalone produced.
MOLLUSCAN AQUACULTURE IN THE UNITED STATES: A BRIEF OVERVIEW1
Authors: Burrell Victor G.
Published: August 2010

Molluscan mariculture species of interest include four oysters, Crassostrea virginica, C. gigas, Ostrea edulis and O. lurida; four clam species, Mercenaria mercenaria, Tapes japonica, Spisula solidissima, and Mya arenaria; blue mussels Mytilus edulis, several abalone Haliotis spp., bay scallops Argopecten irradians and queen conch Strombus gigas.

The American oyster C. virginica leads all molluscan species in landings and about 60% or 12.1 million kilograms of total national production in 1981 was a result of some form of culture. This includes state and private planters' efforts to increase harvest. West coast production of the Pacific oyster was 2.9 million kilograms resulting entirely from mariculture in 1981. The most intense oyster cultivation occurs in New England with production of European oysters, O. edulis, from hatchery produced seed and off bottom culture.

Mariculture in some form accounted for about 4% of total national landings of 1.8 million kilograms for all species of clams in 1980. The hard clam, Mercenaria mercenaria, presently accounts for just about all clam commercial mariculture production.

Blue mussel farming on both the east and west coasts are viable commercial ventures.

Several molluscan mariculture programs have as their goal augmentation of natural stocks which have been reduced by loss of habitat and overfishing.
RICE STRAW AS A FEED SUPPLEMENT FORMacrobrachium rosenbergiiIN PONDS
Authors: Miltner M. , Cange S. , Perry W. G. , Avault J. W.
Published: August 2010

A pilot study was conducted to evaluate air dried rice hay as a detrital feeding substrate for culture ofMacrobrachium rosenbergii.Six 0.13 ha earthen ponds were stocked with post‐larval prawns at a rate of 30,000/ha on 25 May 1982. Two ponds received rice hay biweekly at 9.8 g/m2/week; two ponds received a pelleted ration 5 days/week at 6.2 g/m2/week, and two ponds received both rice hay at 9.8 g/m2/week and the pelleted ration at 3.1 g/m2/week. “Boom and bust” phytoplankton cycles prevailed in ponds receiving rice hay, and sub‐lethal dissolved oxygen levels resulted in reduced prawn survival in ponds. One hay‐only pond had complete prawn mortality due to a sudden die‐off of an algal bloom. Prawns were harvested 12 October after a 133‐day grow‐out period. Prawn yield from a single hay‐only pond was 439 kg/ha; survival was 97.5% and individuals averaged 15 g. Prawn yield in the pellet‐only treatment averaged 600 kg/ha; survival was 90% and individuals averaged 22 g. Prawn yield in ponds receiving both hay and pellets averaged 427 kg/ha; survival was 48%, and individual prawns averaged 29 g. Rice hay or similar agricultural by‐products may have promise as detrital forage to supplement pelletized rations in prawn culture ponds, but further research is required to quantify optimum loading rates, nutritional contribution, and effects on water quality.
GROWTH OF EXPERIMENTALLY CULTURED OCEAN QUAHOGS (Arctica islandica L.) IN NORTH TEMPERATE EMBAYMENTS
Authors: Lutz Richard A. , Goodsell Joy G. , Castagna Michael , Stickney Alden P.
Published: August 2010

The growth of metamorphosed ocean quahogs (Arctica islandica L.) of known age reared from larvae settled in October 1980 was monitored over a 16‐month period using experimental containers suspended from fixed and floating structures in two embayments on the coast of Maine. Specimens ranging in length (maximum antero‐posterior dimension) from 1.8 to 4.3 mm (n = 119; mean=2.5 mm; std. dev. = 0.4 mm) were placed in the containers in June 1981. Shell length measurements were recorded at monthly intervals until October 1982. Water temperatures at the experimental sites ranged from a low of 0.1°C during January 1981 to a high of 21.4°C during July 1982. Maximum growth rates (1.8 to 2.3 mm/month) were observed during the warmest months (June through October). Reduced, yet measurable, amounts of shell (0.3 to 0.5 mm/month) were deposited during even the coldest winter months (January and February). Natural mortality over the 16‐month experimental period was less than 10%. Numerous specimens were randomly sacrificed during the experimental period for subsequent analyses of internal shell growth patterns. By late October 1982 the lengths of the remaining specimens (n=53) ranged from 11.4 to 33.7 mm (mean=26.0 mm; std. dev. = 4.1 mm). Although recorded growth rates are considerably faster than those heretofore reported for Arctica islandica, the growth potential of this species in a suspended culture system does not appear to be high enough to warrant seriously considering this species as a commercial aquaculture candidate.