bluuebunny/crossref_metadata_2025 huggingface dataset:
DETECTION OF IHHN VIRUS IN Penaeus stylirostris AND P. vannamei IMPORTED INTO HAWAII
Authors: Lightner D. V. , Redman R. M. , Bell T. A. , Brock J. A.
Published: August 2010

Infectious hypodermal and hematopoietic necrosis (IHHN), a newly recognized virus disease of penaeid shrimp, was found in populations of blue shrimp (Penaeus stylirostris) and white shrimp (P. vannamei) imported into Hawaii as postlarvae from commercial penaeid hatcheries in Costa Rica and Ecuador. In addition, the disease was detected in populations of post‐larval P. stylirostris imported from commercial and government‐run penaeid hatcheries in Florida and Tahiti, which had obtained all or part of their brood stock from Central or South American sources. IHHN has been found to be a disease of P. monodon as well, but has only been observed in this species when its history has included concurrent culture with stocks of P. stylirostris or P. vannamei.

IHHN was found in Hawaii to be a highly lethal disease of juvenile P. stylirostris, frequently resulting in mortality rates that approached 90% of the affected population. Two populations of P. vannamei were shown to carry the disease, but detection of infections or mortalities due to IHHN in P. vannamei were unusual. These findings indicate that IHHN virus was imported into Hawaii with penaeid populations that originated directly or indirectly from South or Central America, and suggest that the virus is now or has been enzootic in penaeid culture facilities that produce P. stylirostris and P. vannamei in that region, and in Florida and Tahiti.
Renibacterium salmoninarum AS A CAUSE OF MORTALITY AMONG CHINOOK SALMON IN SALT WATER1
Authors: Banner Craig R. , Rohovec J. S. , Fryer J. L.
Published: August 2010

A study to investigate the contribution of Renibacterium salmoninarum to salt water mortality of chinook salmon, Oncorhynchus tshawytscha, was conducted. Smolts were obtained from each of three Oregon Department of Fish and Wildlife hatcheries. Using the direct fluorescent antibody test (DFAT), a determination of incidence of infection by R. salmoninarum was made for groups of fish from the three hatcheries. Samples of fish from each site were placed in separate salt water tanks at the Oregon State University Marine Science Center. Mortalities occurring in salt water were examined for the presence of R. salmoninarum using DFAT, and for other bacterial fish pathogens by preparation of microbiological cultures of kidney tissue on tryptic soy agar. The study included examinations of both the fall and spring release groups from each fish population. Results of the investigation demonstrated the capacity of R. salmoninarum to cause mortality of chinook salmon in salt water and there were indications that horizontal transmission occurred. Detectable incidence of R. salmoninarum before introduction into salt water was higher among populations of chinook released in the spring than in the fall release groups.
A MECHANICAL OYSTER HARVESTER FOR SOUTH CAROLINA ESTUARIES
Authors: Collier J. A. , McLaughlin D. M.
Published: August 2010

A mechanical oyster harvester has been developed for the intertidal oyster (Crassostrea virginica). The harvester is hydraulically powered and mounted on a 16 m steel hull vessel designed for its operation. The objective of this research was to produce a machine that would efficiently harvest oysters while doing minimum damage to the oysters and the fragile shell matrix that supports them. Results of three years' testing show harvest rates of 18 m3 /hour. Damage to the shell matrix was almost undetectable and damage to the harvested oysters was about 5%. The harvester can operate at depths of one to 3 m with the head controlled automatically. Bottom contact force is adjustable and regulated automatically during harvest to minimize bottom damage. The harvesting head can pitch or roll 0.35 rad to follow bottom contour. Future plans for the harvester include leasing to the L. P. Maggioni Oyster Company for commercial harvest during the 1982‐83 season. Eventually the harvester will be used by the state of South Carolina for oyster bed management and transplanting of oysters from polluted areas to public shellfish grounds.
MODELING THE DIEL OXYGEN RESPONSE OF A SMALL FISH POND
Authors: Meyer Doreen , Brune D. E. , Haight Boyd
Published: August 2010

A recently developed mathematical model of stillwater pond aquaculture is discussed. Comparisons are made between computer generated diel oxygen cycles and actual field data and the simulations are seen to compare favorably in many cases. A sensitivity analysis of important management and environmental variables is discussed. This model is based on a first principles approach and is neither site nor species specific, however, it does contain certain limitations and shortcomings. These are discussed and areas for future improvements are identified.
COMPUTER AIDED OPTIMUM DESIGN AND CONTROL OF STAGED AQUACULTURE SYSTEMS
Authors: McNown W. , Seireg A.
Published: August 2010

This paper deals with development of a generalized computer program which can be utilized for the optimum design of multi‐stage recirculating aquaculture systems. The program incorporates culture organism growth, energy management, plant location, market conditions, harvest date, and harvest size. The program is capable of optimizing the plant design and its operation taking into consideration the economic effects of using insulated culture environment and utilization of solar energy. A unique feature of the program is its ability to select the optimal number of stages for a particular species and set of operational constraints. Dynamic programming is used for the optimization process. The program's capability is illustrated by its application to the design of plants for raising rainbow trout and yellow perch in recirculating culture systems. Considerable savings can be achieved due to the optimum selection of stages and energy policy.
LABORATORY AND FIELD STUDIES ON THE TOXIC EFFECTS OF THIOBENCARB (BOLERO) TO THE CRAWFISH Procambarus clarkii
Authors: Sommer Ted R.
Published: August 2010

The effects of the herbicide thiobencarb (Bolero) were tested on the crawfish Procambarus clarkii using both laboratory and field methods. A 96‐hour static bioassay was conducted to determine the LC50 of this compound for juvenile crawfish. The LC50 was computed to be 0.47 ppm, which was similar to previously measured field concentrations. Adult P. clarkii were also tested and were shown to be susceptible to thiobencarb toxicity at levels similar to actual field concentrations. A parallel experiment demonstrated that the herbicide molinate (Ordram, LC50 = 6.13) was much less toxic than thiobencarb to juvenile crawfish.

The population structure of the crustaceans was measured both before and after herbicide application in the field. After application of thiobencarb the catch of juveniles declined significantly and the smaller size classes became almost undetectable.

The catch of adults also decreased significantly. However, analysis of size distributions, burrow excavations and visual counts revealed that the adults did not experience large‐scale mortality. Instead, many adults had burrowed to initiate breeding activity. It is hypothesized that burrows may provide a buffer zone against the toxic effects of the herbicide, thereby insuring survival of populations.
ECONOMIC ANALYSIS OF SMALL‐SCALE PRAWN FARMING IN SOUTH CAROLINA1
Authors: Smith Theodore I. J. , Liao David S.
Published: August 2010

In 1982, a producer survey was conducted to evaluate the economic potential of small‐scale prawn farming, Macrobrachium rosenbergii, as a supplemental source of income in South Carolina. Based on survey data, total costs were estimated to be $1,883.78 and total gross returns were $2,041.69 per 0.4 ha pond, thereby producing a net return of $157.91/0.4 ha pond. Producers felt that marketing was not a problem but all producers identified the non‐availability and high cost of seed stocks as a major problem confronting development of an industry.

A survey of prawn consumers was conducted to assess product acceptance and preference. The majority of consumers indicated preference for the heads‐off form in the 57–110 tail count/kg size category and would purchase prawns about once a month, if available.
PRELIMINARY REPORT ON SHRIMP CULTURE ACTIVITIES IN ECUADOR
Authors: Hirono Yosuke
Published: August 2010

In recent years, the ancient practice of shrimp culture in Japan has spread around the world. Ecuador has become the largest producer of pond‐grown shrimp in the world with production of over 11,400 metric tons in 1982. This represents an annual rate of increase of approximately 40% since 1977.

The expanding shrimp culture industry is transforming its production method from traditional extensive cultivation to the semi‐intensive method with supplemental feeding and pond management techniques introduced by foreign scientists. Subsequently, anticipated pond production will reach 45,500 metric tons within a five‐year period, assuming the availability of necessary seed‐stock, the raw material for shrimp feed, and trained aquaculture specialists.

At this moment, Ecuador has approximately 35,000 ha in production and another 10,000 ha under construction. The growing pains of the industry and the production levels of various systems are discussed.
GROWTH OF NORI (Porphyra tenera) IN AN EXPERIMENTAL OTEC‐AQUACULTURE SYSTEM IN HAWAII
Authors: Mencher F. M. , Spencer R. B. , Woessner J. W. , Katase S. J. , Barclay D. K.
Published: August 2010

The use of OTEC (Ocean Thermal Energy Conversion) effluents for aquaculture presents several benefits: reduced pumping costs, large‐scale temperature control, high water quality, and elevated levels of inorganic nutrients. Intensive culture of many temperate‐water organisms should be technically possible using these effluents. Nori (Porphyra tenera), a valuable edible red seaweed, is among the organisms being cultured experimentally in OTEC‐like water at the Natural Energy Laboratory of Hawaii, Keahole Point, Hawaii.

Nori was cultured in 7 1‐m3 tank compartments with a mixture of deep (600 m) and surface water resulting in the following conditions: 15°C, 30 l/min flow rate, 26–29 μg‐at/l influent N concentration, 2‐2.5 μg‐at/l influent P concentration, 8‐hour photoperiod. The initial stocking density was 20 g wet weight (4.1 g dry wt) per compartment.

After 39 days the nori averaged 4700±1525 g wet wt (622±121 g dry wt) per compartment. Maximum short‐term production rate was 27.9±7.7 g dry wt m‐2 day‐1. The nori extracted a maximum of 57% and 27% of the influent N and P, respectively, with 22–47% and 6–17% being more typical daytime values during the last two weeks. Little nutrient uptake occurred at night. Noon measurements revealed no significant excretion of organic C, N, or P; 24‐hour measurements were equivocal. Tissue N concentration (indicative of quality) was high relative to Japanese cultured nori during the first 3 weeks, but declined somewhat thereafter. P. tenera appears to have good potential for culture in OTEC effluents.
THE EVOLUTION OF INTEGRATED AQUACULTURE SYSTEMS1
Authors: Ryther John H.
Published: August 2010

Oxidation ponds have been used for many years for treatment of domestic wastewater. Nutrients and carbon dioxide produced by the decomposing organic wastes enhance the growth of unicellular algae which, in turn, provide oxygen for the bacterial decomposition. When such ponds have an effluent, however, the algae themselves represent a loading of organic matter that fails to meet discharge standards, so the algae must be removed from the water. Conventional harvest techniques are uneconomical, particularly in view of the low value of the product.

An alternative is to allow the plants to be consumed by filter‐feeding or grazing fish or invertebrates that harvest the plants at no cost and, in the process, produce an animal crop that has potential commercial value.

Polyculture systems, involving freshwater fishes low on the food chain grown in ponds enriched with a variety of organic wastes, have been used for centuries in China. The practice has spread to many other countries and the concept has begun to be used in estuarine mariculture. Usually the ponds are stagnant, with no effluent, and the objective is fish production, not waste treatment.

Recently, similar waste recycling‐polyculture systems have been developed experimentally on a flow‐through basis with the dual objectives of both fish (and/or invertebrate) production and advanced wastewater treatment (specifically nutrient removal). Several recent examples of quite different freshwater systems and a fewer number of marine systems are briefly described. Problems and constraints of such practices are also discussed.
WATER QUALITY IN INTEGRATED LIVESTOCK‐FISH PONDS1
Authors: Hopkin Kevin D. , Inocencio Perlina , Cruz Emmanuel M.
Published: August 2010

Water quality variables were monitored during 3.5 years of research on pig‐fish; duck‐fish and chicken‐fish systems. Early morning dissolved oxygen levels were often below 0.5 mg/l. Total ammonia levels were highest in chicken‐fish systems with maximum levels exceeding 6 mg/l. Water quality sampling designs which measure the fluctuations in water quality variables are discussed. Species selection, control of manure loads, addition of new water, and aeration are presented as means to manage water quality in livestock‐fish systems.
DEPURATION AND PUBLIC HEALTH
Authors: Blogoslawski Walter J. , Stewart Mary E.
Published: August 2010

This paper reviews briefly the viral, bacterial, and toxic diseases borne by shellfish that are transmissible to man. Methods available to cleanse or depurate contaminated bivalves are also presented. Each method is evaluated with regard to 1) present and past use, 2) economic cost benefits, and 3) ability to prevent disease transmission.
GENETICS IN BIVALVE AQUACULTURE: 1983 AND STILL LOTS OF POTENTIAL
Authors: Newkirk Gary F.
Published: August 2010

To date genetics has made no significant impact on bivalve aquaculture. There have been obstacles to the implementation of selective breeding in bivalve culture but the primary reason for so little progress must be a lack of a concerted effort to develop effective programs. However, there is evidence that more commercially valuable stocks can be obtained with controlled breeding programs. Different approaches to improvement include hybridization, induced polyploidy and mass selection. Mass selection has the inost potential for immediate application to commercial breeding. Experimental results have indicated the other approaches have potential but their application to commercial breeding programs have not been demonstrated. Although no controlled selective breeding programs are known to exist in commercial bivalve hatcheries, selective breeding programs can be compatible with the operation of a commercial hatchery if the operators see genetics as an essential part of the complete husbandry of bivalve stocks.

It is probably safe to say that to date genetics has made no significant impact on the operation of, or the production from, bivalve aquaculture. This is true in spite of encouraging predictions about the application of genetics to oyster culture which go back as far as 1924 (Wells 1924). There have been obstacles to the implementation of selective breeding in bivalve culture but the primary reason must be a lack of a concerted effort to develop effective programs once an adequate level of control of hatchery production has been attained.

In this paper a brief discussion of hybridization, induced polyploidy and selection as general approaches to the breeding of bivalves will be presented. A more extensive review of published results and their application can be found in Newkirk (1983). Here emphasis is placed on the importance of controlled breeding in commercial hatcheries. A general argument is presented that genetic improvement is not necessarily a long‐term prospect and it should be possible to evaluate the benefit/cost ratio of such a program for a particular situation.
POND CULTURE OF STRIPED BASS X WHITE BASS HYBRIDS
Authors: Kerby Jerome Howard , Woods L. Curry , Huish Melvin T.
Published: August 2010

Four 0.1‐hectare earthen ponds were stocked with two densities (10,000 and 15,000 fish/hectare) of female striped bass (Morone saxatilis) X male white bass (M. chrysops) hybrids on 30 October 1980. Mean weight at stocking was 20 g. Fish were fed ad libitum 2 or 3 times daily with a dry commercial salmon diet, and ponds were aerated mechanically during periods of low dissolved oxygen in warm months. Survival to harvest about 13 months later (22 November 1981) averaged 50% in the low density ponds and 93% in one high density pond. Total mortality of fish in the other high density replicate occurred in late August after an aerator failed. Survival until then was 92%. At harvest, mean weight of fish was 465 g in the low density ponds and 351 g in the high density pond. The average food conversion ratio of dry food to wet fish weight was 1.58:1. Standing crop at harvest averaged 2,312 kg/hectare in the low density ponds and was 4,886 kg/hectare in the high density pond. Growth was positively correlated with temperature, with the most rapid growth rates occurring during periods of high mean water temperatures. The study demonstrated that the hybrids can be grown to marketable sizes in ponds within 15–18 months of age at densities similar to those used in culture of channel catfish (Ictalurus punctatus). In view of their high market value, we believe that this hybrid has considerable potential for culture as a commercial food fish or perhaps for use in fee‐fishing ponds.
SURVIVAL, METAMORPHOSIS AND GROWTH OF PENAEID SHRIMP LARVAE REARED ON A VARIETY OF ALGAL AND ANIMAL FOODS
Authors: Wilkenfeld Joshua S. , Lawrence Addison L. , Kuban Frank D.
Published: August 2010

Experiments conducted with Penaeus aztecus, P. setiferus and P. vannamei compared survival, metamorphosis and dry weight growth of larvae fed a variety of algal and animal food regimes. The major objectives were: (a) comparison of the nematode Panagrellus redivivus and the brine shrimp Artemia as animal food sources and (b) comparison of effects of feeding diatoms (Skeletonema costatum and Chaetoceros gracilis) vs phytoflagellates (Isochrysis sp. and Tetraselmis chuii) with nematodes or brine shrimp nauplii added to the diet starting at the protozoea‐two or mysis‐one substage.

Specific feeding regimes were identified for each shrimp species tested which would allow for total or partial replacement of Artemia as the animal food source, without reducing production results. However, Panagrellus redivivus was found to be less versatile than Artemia nauplii in terms of overall nutritional value to the shrimp larvae. The superiority of using two diatom species vs two phytoflagellate species as an algal food source for penaeid shrimp larvae demonstrated in earlier experiments was confirmed.

The results strongly suggest that evaluation of rearing regimes used for production of penaeid postlarvae should include growth in terms of dry weight, as well as survival and rate of metamorphosis.
PRODUCTION OFPenaeus vannameiIN CATTLE MANURE‐ENRICHED ECOSYSTEMS IN HAWAII
Authors: Lee Cheng‐Sheng , Shleser Robert A.
Published: August 2010

The first experiment of this study was conducted in 1981 usingPenaeus vannameifrom Ecuador. Animals weighing an average of 3.8 g were stocked in seven earthen ponds (163 m2) at an average density of 9.2 animals/m2. The shrimp in two of the ponds were fed Ralston Purina MR20 shrimp feed daily. The remaining five ponds were not fed, but were enriched with cattle manure plus inorganic fertilizer. After 62 days the average body weight was 20.3 g. The average weekly weight gain and average survival were 1.82 g and 54.05% respectively for ponds fed commercial feed, and 1.89 g and 59.9% for ponds enriched with fertilizer.

The second experiment was conducted in 1982, usingP. vannameifrom Costa Rica. Four ponds (163 m2), Group 1, were stocked with 6.5 g animals at a density of 7.1 animals/m2. An additional four ponds as Group 2 were stocked with 3.2 g animals at a density of 9.4 animals/m2. One pond from each group received one of the following four treatments: no external inputs, feeding with MR20 feed or fertilizing with cattle manure 0.5 kg/m2or 1.0 kg/m2. After 77 days the average weight was 17.88 g in Group 1 and 16.93 g in Group 2. There was a significant difference in growth rate between Group 1 and Group 2. Survival for all treatments was greater than 71.4% and averaged 80.7%. Water quality was monitored in both experiments. Water temperatures were higher in experiment 1 than in experiment 2. No correlations have been drawn between growth rates, water quality parameters, and treatments, in either experiment.

In conclusion,P. vannameican be raised in cow manure‐enriched ecosystems at a stocking rate of 9.4 animals/m2.
SEED STOCK FOR LOBSTER CULTURE: THE ROLE OF TEMPERATURE IN SYNCHRONIZING THE MOLT AND REPRODUCTIVE CYCLE OF CULTURED AMERICAN LOBSTERS
Authors: Waddy S. L. , Aiken D. E.
Published: August 2010

Female lobsters reared under high culture temperatures (20°C) have been poor producers of eggs and for this reason wild stock have been the source of seed for culture production. However, improvements in our understanding of the temperature control of female reproductive cycles have made it possible to obtain eggs and larvae from cultured brood stock and accelerate the development of a domesticated strain. More than 200 fast‐growing female lobsters hatched and reared in our intensive culture system are now being used as brood stock. During 1983, 2,500 fourth stage larval lobsters were obtained from cultured parental stock. These larvae are the first second generation lobsters reported from culture‐culture crosses and represent the first significant step in the development of domesticated lobsters for intensive culture.
PRELIMINARY OBSERVATIONS OF ORANGEMOUTH CORVINA SPAWN INDUCEMENT USING PHOTOPERIOD, TEMPERATURE AND SALINITY CYCLES
Authors: Prentice John A. , Colura Robert L.
Published: August 2010

Subadult orangemouth corvina (Cynoscion xanthulus) collected in fall 1981 from the Salton Sea, California, were transported to Texas to determine methods to induce spawning in indoor closed culture systems. Sexual naturation was stimulated with artificially controlled annual photoperiod, water temperature and salinity cycles which mimicked conditions historically found at the Salton Sea. Corvina readily adapted to intensive culture and grew rapidly, approaching maturity by spring 1982. Sexual development was monitored by catheterization. Corvina were found to be summer spawners. Males approximately 500 mm total length became sexually mature, producing milt from at least June to October of the 1982 and 1982‐83 cycles. Females approximately 590 mm total length developed eggs (0.05‐0.70 mm diameter, unhydrated) from at least June to October of the 1982‐83 cycle, but did not spawn. Because spawning had not occurred by late summer 1983 and egg development stopped progressing, two females with egg diameters of 0.40‐0.55 mm were each administered a single injection of 550 USP units/kg body weight human chorionic gonadotropin. Egg hydration and ovulation occurred within 30 hours of hormone injection in each female. The first female had many eggs clumped in masses but was able to release eggs which appeared fully developed. The other female died because hydrated eggs were clumped together in large masses and could not be released. Males attended females during the time of egg hydration and ovulation and apparently released milt, but no eggs developed or hatched. Experiments to induce spawning are continuing.
DEVELOPMENT OF A COLD‐TOLERANT POPULATION OF RED TILAPIA THROUGH INTROGRESSIVE HYBRIDIZATION
Authors: Behrends L. L. , Smitherman R. O.
Published: August 2010

A population of red tilapia with cold tolerance traits similar to Tilapia aurea has been produced using introgressive breeding techniques, i.e., hybridization (female T. aurea x male red tilapia, heterozyqous for red trait) followed by backcrossing (female T. aurea x F‐1 male, red phenotype). Progeny of the F‐1 backcross, consisting of approximately 50% normal and 50% red phenotype, survived longer under conditions of ambient cooling than either T. aurea or T. mossambica (P < 0.05). There were no differences in cold tolerance between the normal and red phenotypes of the F‐1 backcross population (P > 0.05). Mean lower lethal temperatures for the three groups were: T. aurea (11.6 °C), T. mossambica (13.8 °C), and F‐1 backcross, red and normal phenotypes pooled, 10.0 °C.
RESPONSE OF Tilapia aurea TO DIETARY VITAMIN C
Authors: Stickney Robert R. , McGeachin Robert B. , Lewis Donald H. , Marks Jon , Riggs Alan , Sis Raymond F. , Robinson Edwin H. , Wurts William
Published: August 2010

Two experiments were conducted to determine the dietary requirement for vitamin C of young Tilapia aurea. In the first experiment, best growth and food conversion were obtained over 14 weeks on a diet which contained 50 mg/kg of vitamin C (other levels tested were 0, 100 and 200 mg/kg). In the second experiment, levels of 0, 25, 50, 65, 80, 95 and 110 mg/kg of vitamin C were employed and, again, growth and food conversion did not improve at dietary vitamin C levels above 50 mg/kg. Pathologic changes were observed in fish maintained on rations containing 25 mg/kg or less vitamin C. Gross changes included mild scoliosis and occasional hemorrhages of the fins, mouth and swim bladder. Histologic changes included shortening and thickening of gill lamellae and disorganization of chondrocytes in tips of gill filaments and bases of gill arches.
PREVENTION AND MANAGEMENT OF INFECTIOUS DISEASES IN INTENSIVE MOLLUSC HUSBANDRY
Authors: Elston Ralph A.
Published: August 2010

Principles for management of infectious diseases in intensive mollusc husbandry are presented as derived from an evaluation of pertinent literature and general principles of health management. Both opportunistic pathogens and obligate agents of disease are managed in terms of finite entry points in husbandry systems: brood stocks, algal food stock and seawater source. Opportunistic bacterial diseases, particularly vibriosis, are presently the most significant diseases. Bacteria expand in the culture system in a preclinical phase and subsequently cause primary disease both by direct infection by bacteria and by toxin‐mediated processes. Primary disease involving direct infection and growth of bacteria in ligament and soft tissues appears to be the most significant mechanism of infection in metamorphosing and juvenile animals, the critical phase in intensive mollusc husbandry. Diagnosis and management of the disease depend on recognition of the disease and determination of the source of infectious organisms. Obligate intracellular diseases are prevented and managed by control of animal movements, prevention of cross contamination and sterilization of effluents from animal tanks.
DISEASE TREATMENT IN HARD CLAMS, Mercenaria mercenaria1
Authors: Kraeuter John N. , Castagna Michael
Published: August 2010

Diseases have been considered to be major factors in the failure of laboratory and commercial bivalve culture. Much of the work on disease has concentrated on the larval stages, but little information exists for the period from settlement to the age of about nine months. We noticed substantial mortalities of 2–10 mm shell height Mercenaria mercenaria which had been held all winter in the grow‐out facility of our laboratory. In subsequent years we developed several methods for treating the clams to decrease the mortalities. Although presumptive tests indicated the presence of Vibrio bacteria we did not confirm the etiological agent and did not establish direct evidence that bacterial pathogens caused the observed mortalities. The most effective treatment tested for general purpose commercial usage was a two‐hour bath of bleach at either 9 or 18 ppm.
DEPTH DISTRIBUTION AND COMPOSITION OF MACROINVERTEBRATE COMMUNITIES IN ENRICHED, LOW‐SALINITY FISH CULTURE PONDS
Authors: Perschbacher Peter W. , Strawn Kirk
Published: August 2010

Planktonic, nektonic and epifaunal, and benthic invertebrate comunities were sampled at 2‐week intervals in Gulf killifish (Fundulus grandis) grow‐out ponds east of Baytown, Texas. Conductivity increased in a summer trial, range 3–14 mmhos/cm (2–9 ppt salinity) and decreased in a fall‐winter trial, range 12–31 mhos/cm (8–22 ppt salinity). Replicated treatments in the summer trial were inorganic fertilization only, fertilization and supplemental feeding at 3% of fish body weight daily, and feeding at 3% body weight only; and in the fall‐winter trial, fertilization, feeding at 5% body weight once daily, and feeding at 5% body weight divided into daily portions.

In both trials, copepods and rotifers numerically dominated the zooplankton samples, ostracods the nekton‐epifaunal samples, and chironomid larvae and ostracods the benthic samples. Fertilization significantly increased primary productivity and the abundance of copepods, rotifers, corixids and chironomid larvae (major food sources). Supplemental feeding significantly increased numbers of polychaete larvae and adults, and bivalves. Ostracods, corophiid amphipods, and mayfly and damselfly nymphs varied independently of treatment. In terms of depth distribution, in early September chironomid larvae and amphipod and in December ostracod abundance declined with depth from the pond bank. In the December core transect polychaete and chironomid larvae density followed the reverse of this trend. Bivalves were most abundant on the gradual slope 0.92‐1.11 m in depth.

Low salinities at this site enhanced aquatic insect and insect larva populations and reduced the importance of polychaetes. Gulf killifish production on natural foods alone was high.
A GENERAL MODEL OF THE AQUACULTURE POND ECOSYSTEM
Authors: Piedrahita Raul H. , Brune David E. , Tchobanoglous George , Orlob Gerald T.
Published: August 2010

A computer model of a fertilized warm‐water aquaculture pond has been developed. The model is intended to represent the pond ecosystem and its response to external stimuli. The major physical, chemical, and biological processes and parameters are included in the model. A total of 22 state variables are used in the model (dissolved oxygen, ammonia, alkalinity, phytoplankton, zooplankton, fish, etc.). The model is fonnulated as a system of mass balance equations. The differential equations include stimulatory and inhibitory effects of environmental parameters on processes taking place in the pond. The equations may be solved for the entire growth period and diurnal as well as seasonal fluctuations may be identified.
THE EFFECTS OF FEEDING RATES ON THE DYNAMICS OF GROWTH OF BLACK DRUM AND SPOT CAGE CULTURED IN A HEATED WATER LAKE
Authors: Jones Fredrick V. , Strawn Kirk
Published: August 2010

Black drum (Pogonias cromis) and spot (Leiostomus xanthurus) were cage cultured in a cooling lake of a power plant near Baytown, Texas, from June through September 1978 and June through November 1977, respectively, to determine the effects of varying feeding rates on the dynamics of growth. Temperature, salinity, pH and dissolved oxygen were monitored daily and fish were measured and weighed either monthly or at two‐week intervals to determine growth rates.

Survival was poor for spot due to handling stress, and excellent for black drum. Instantaneous growth rates were correlated to temperature, salinity, fish size, and feeding rate. Mean food conversion efficiency (FCE) was correlated to size and feeding rate. Maximum growth rates occurred at temperatures between 27–30°C. Growth rates increased with increasing salinity, and large fish grew faster at higher salinities than small fish. Growth rates increased with increasing feeding rates up to and slightly beyond the maximum daily ration, then declined. FCE decreased curvilinearly with increasing ration up to the maximum daily ration, then remained stable. Growth rates and FCE declined curvilinearly with increasing fish size.
EFFECTS OF SIZE AT STOCKING ON COMPETITION AND GROWTH OF ALL‐MALE TILAPIA HYBRIDS
Authors: McGinty Andrew S.
Published: August 2010

Triplicate ponds (0.07‐ha) were stocked with either a single size group (11–12 cm) or mixed size groups (either smalls 7–8 cm, mediums 11–12 cm or larges 15–16 cm) of all‐male tilapia hybrids of female Tilapia nilotica x male T. hornorum. After 140 days, smalls, mediums and larges gained 1.89, 3.10 and 2.59 g/day in mixed stocking, respectively, while mediums in single stocking gained 2.59 g/day. In mixed stocking, growth of smalls was depressed due to competition with mediums, larges, or both. Larges apparently expended mre energy on nest building and guarding, thus allowing mediums to maximize their food intake and growth. Lack of a predetermined hierarchy under single stocking resulted in depressed growth.
FEEDING ECOLOGY OF HYBRID STRIPED BASS (Morone saxatilis x M. chrysops) IN CULTURE PONDS
Authors: Woods L. Curry , Lockwood Jeffrey C. , Kerby J. Howard , Huish Melvin T.
Published: August 2010

A study of the relative importance of food organisms utilized by hybrid striped bass (Morone saxatilis x M. chrysops) was conducted at the Dennis Wildlife Center in Bonneau, South Carolina. Objectives were to determine the food items of major importance and to document the availability, utilization and preference of zooplankton by one‐ to five‐week‐old hybrid striped bass.

We collected twenty‐five plankton samples and 300 hybrids from each of five 0.2 ha culture ponds. The dominant taxa of net zooplankton in decreasing order of occurrence were Bosmina, Daphnia and Cyclopidae. Dominant genera of zooplankton in hybrid stomachs in decreasing order of occurrence were Cyclops, Daphnia and Bosmina. Selectivity indices calculated for the three most important taxa of zooplankton showed that hybrid striped bass preferentially selected Cyclops and Daphnia and avoided Bosmina. Insect larvae and ostracods were other food items found in many stomachs.
ECONOMIC FEASIBILITY OF SHRIMP FARMING IN TEXAS: AN INVESTMENT ANALYSIS FOR SEMI‐INTENSIVE POND GROW‐OUT
Authors: Hanson J. S. , Griffin W. L. , Richardson J. W. , Nixon C. J.
Published: August 2010

A firm level simulation model (MARSIM) was developed to analyze the survival of different shrimp farm sizes in Texas. The model simulates the annual activities of a shrimp farm: production, finances, cash receipts, capital replacement and depreciation, cash flows, income taxes, balances, and growth. A firm is replicated 50 times over a 10‐year planning horizon. Random values for shrimp growth and survival, temperature, hurricanes, and prices received in each of 10 years are generated from multivariate empirical probability density functions (pdf) for these variables. For the analysis summarized here, a shrimp farm was simulated using 3 different size systems and 4 different pond sizes. Results indicate that higher rates of return and faster payback are associated with larger total farm size and larger ponds. For large farms (400 surface hectares), pond size becomes less critical to obtaining an acceptable rate of return to investment. The amount of time taken to construct a facility significantly impacts the rate of return. Hurricanes, prices, production, and temperature variation are also critical factors affecting the firm's returns and survival.
EVALUATION OF THREE BIOLOGICAL FILTERS SUITABLE FOR AQUACULTURAL APPLICATIONS
Authors: Miller G. E. , Libey G. S.
Published: August 2010

A staged rotating biological contactor (RBC), packed tower (PT, trickling filter) and fluidized bed reactor (FBR) were tested simultaneously using common water from a fish culture tank. The culture tank was stocked with channel catfish (Ictalurus punctatus) at three different densities (approximately 227, 113 and 57 kg/m3) to provide solute concentrations in the filter influent similar to those expected under intensive culture practices.

Mean concentrations of total ammonia nitrogen (NH4+‐N + NH3‐N) in the culture tank were 1.46 (3.50‐0.42), 1.26 (1.78‐0.95) and 0.36 (0.48‐ 0.28) mg N/liter at the respective stocking densities. The RBC provided the best nitrification efficiencies (74%, 82% and 76%, respectively). The efficiency of the PT (23%, 42% and 51%) was somewhat better than the FBR (8%, 28% and 32%). The rate of ammonia removal across the entire RBC was 0.79, 0.63 and 0.19 g N/m2d‐1, with removal across the first two stages of 1.31, 1.15 and 0.31 g N/m2d‐1. The PT provided arranonia removal of only 0.25, 0.32 and 0.14 g N/m2d‐1.

Dissolved oxygen, nitrite, nitrate, pH, alkalinity and chemical oxygen demand analysis was also performed.
PROCEDURES AFFECTING THE PRODUCTION AND PROCESSING OF SOFT‐SHELLED CRAWFISH
Authors: Culley D. D. , Said M. Z. , Culley P. T.
Published: August 2010

Production technology for soft‐shelled red swamp crawfish (Procam barus clarkii) was investigated. Immature trapped crawfish molted when placed under intense (100/m2) short‐term culture at a rate of 3.8% of the population/day when provided a diet of floating trout pellets. Other diets (carrots, cracked corn and milo, and low protein duckweed) yielded daily molting rates of 2, 1.6 and 1.4%, respectively. Pre‐ and postmolt weights of crawfish were not different. Processing by (1) removal of rostrum and gastroliths; (2) removal of internal organs, plus (1); and (3) removal of carapace plus (1) and (2) yielded 92, 79 and 72% edible product. Crawfish collected by seining yielded a greater number of molts over a 10‐day period than trapped crawfish.
EFFECT ON GROWTH AMD APPARENT DIGESTIBILITY OF DIETS VARYING IN GRAIN SOURCE AND PROTEIN LEVEL INMacrobrachium rosenbergii
Authors: Ashmore S. B. , Stanley R. W. , Moore L. B. , Malecha S. R.
Published: August 2010

Two studies each consisting of a growth and digestibility trial were carried out to evaluate the nutritive merit of four cereal grains (corn, milo, wheat and barley) in diets formulated forMacrobrachium rosenbergii. In the first growth trial four isonitrogenous, isolipidic and isocaloric (gross energy) diets differing in their grain source were fed to prawns with an initial mean weight of 7.3±0.1 g. After 12 weeks the barley based diet produced greater growth than the wheat based diet. No significant differences in feed conversion ratios, protein efficiency ratios, or feed consumption were observed. The same diets containing 1% chromic oxide were fed to larger animals (40–50 g) to determine apparent digestibility of protein and energy. Apparent digestibility of dietary energy ranged from 76.8% to 79.1% for the four diets tested and was significantly lowest in the wheat diet. Apparent digestibility of protein ranged from 84.1% to 88.9% and did not vary significantly among diets. In the second growth trial prawns with an initial mean weight of 4.1±O. l g were fed six isolipidic, isocaloric diets varying in protein level (20%, 30% or 40%) and grain source (wheat or barley). Growth at 12 weeks was significantly different among treatments. The wheat and barley 30% and 40% protein diets supported greater growth than the 20% protein wheat diet. The 40% protein wheat diet and 30% protein barley diet supported greater growth than the 30% protein wheat diet. Higher feed consumption was observed with the higher protein diets. No differences between feed and protein conversion ratios were observed among diets. In the second digestibility trial, apparent digestible protein was not significantly different among treatments, however, digestible energy was significantly different among treatments. It appears from the results that feed consumption and apparent digestible energy contributed to the growth response observed in the two growth trials. At the 30% dietary protein level, barley appears to have been more efficiently utilized than wheat, effectively reducing the level of required dietary protein.
THE EFFECT OF EARTHEN POND BANK GRASS ON PRAWN YIELD1
Authors: Wang Jaw‐Kai , Losordo Thomas M.
Published: August 2010

A paired‐t test has shown that, statistically, proper shortening of the pond bank grass covering increased the harvested yields of production ponds. This increase is assumed to be due to higher harvest efficiencies and the resultant timely removal of as many market size prawns as possible. From October 1983 to May 1984, an annual adjusted yield of 2,300 kg per harvested hectare was achieved in ponds with properly maintained banks. In contrast, ponds with long grass covered banks yielded 1,916 kg per harvested hectare. These results showed clearly the importance of high harvest efficiency in managing a fresh water prawn production facility.
MATURATION AND SPAWNING OF ABLATED AND NONABLATEDPenaeus semisulcatusde HAAN (1844)
Authors: Browdy Craig L. , Samocha Tsachi M.
Published: August 2010

Reproductive performance of unilateral eyestalk ablated and unablated wild and pond rearedPenaeus semisulcatuswas compared in a series of experiments in Eilat, Israel. Tagging techniques were used to study the maturation and spawning of individual females. The average numbers of spawns and eggs per ablated females were more than double those produced by unablated females, although fewer eggs per spawn were produced by ablated females. There were no significant differences in spawn quality, as measured by the percent fertility, hatch, and metamorphosis to zoea 1, between ablated and nonablated females. Egg production of ablated females was consistent for 70 to 80 days after which a decline was observed. The average rate of egg production of nonablated shrimp was more erratic with an apparent decline only after 100 to 110 days.

No significant differences were found in spawn size or spawn quality between the first three spawns of ablated and nonablated females. A significant reduction in spawn size was apparent over the molt cycle although the percent fertility remained constant. Spermatophore transfer rates of 84 to 92% were achieved with female to male rations of 1.8:1 to 2.5:l. A reduction in fecundity was observed for successive generations of pond‐reared brood stock.

Eyestalk ablation was used to stimulate spawning of P.semisulcatusin captivity with no significant reduction in brood stock survival or in spawn quality.
PRELIMINARY INVESTIGATION OF THE EFFECTS OF TEMPERATURE, BACTERIAL INOCULATION, AND EDTA ON SPERM QUALITY IN CAPTIVEPenaeus setiferus
Authors: Bray William A. , Leung‐Trujillo Joanna R. , Lawrence Addison L. , Robertson Stephen M.
Published: August 2010

A 60‐day preliminary study was conducted to determine whether excessive temperature, bacterial infection, or heavy metals contamination contributed to spermatophore and sperm deterioration in laboratory‐heldPenaeus setiferusmales. Three treatments were tested in which: 1) culture water temperature was held at 25–26°C; 2) males were inoculated with a killedVibrio sp. bacterin; and 3) EDTA (ethylenediaminetetraacetic acid) was added to culture water at 25 ppm. These were compared with a control treatment at mean ambient temperature of 29.1°C. A combination of males from the primary offshore breeding population (mean weight 43.9 g ± 1.78 S.E.M.) and young‐of‐the‐year males (mean weight 24.5 g ± 0.83) were used. Mean baseline values (± S.E.M.) established at initiation were, per male: sperm count, 38.7 × 106± 10.165 × 106; percent abnormal sperm, 5.0% ± 1.13; and spermatophore weight, 0.103 g ± 0.0215. At the midpoint 30‐day samples, mean sperm counts were significantly lower in the ambient and EDTA treatments. The chilled and inoculated treatments showed no decline in sperm counts during the first 30‐day period, but the percentage of abnormalities had increased from 5.0% ± 1.13 in the baseline to 16.3% ± 9.94 and 57.0% ± 9.64, respectively. At termination (60 days), only the chilled treatment contained any males bearing sperm (33% of males sampled from the treatment), but sperm abnormalities ranged from 53–72%. Results indicate that parameters tested did not prevent decline in male reproductive condition over time.
EFFECTS OF DIET AND SIZE ON GROWTH, FEED DIGESTIBILITY AND DIGESTIVE ENZYME ACTIVITIES OF THE MARINE SHRIMP,Penaeus setiferusLINNAEUS
Authors: Lee Phillip G. , Lawrence Addison L.
Published: August 2010

Relationships between protein level, size, apparent feed digestibility, digestive enzyme activities and growth ofPenaeus setiferuswere investigated during a 30‐day growth trial. Small (3.7 g), medium (9.5 g), and large (14.7 g) shrimp were fed four isocaloric diets with varying protein levels. Apparent total dry matter digestibilities and apparent protein digestibilities were determined for small and medium shrimp. General and acid protease, trypsin, carboxypeptidase A and B, amylase, chitinase, non‐specific esterase and lipase activities were also assayed for small and medium shrimp.

Shrimp survival was unrelated to diet or size. Instantaneous growth rate, total dry matter and protein digestibilities decreased as shrimp size increased. Small shrimp fed the 22% protein diet grew the least but exhibited the highest enzyme activities, especially carbohydrases. Small shrimp fed the 38% protein diet displayed the highest dry matter digestibility. Medium shrimp fed the 30% protein diet exhibited the lowest survival and growth while medium shrimp fed the 22% protein diet exhibited the highest enzyme activities. Higher digestive enzyme activities on the 22% protein diet may be evidence of an adaptation to a diet containing less digestible proteins.
INTERNATIONAL STUDY ONArtemia1XXXIII. PROMISING RESULTS IN LARVAL REARING OFPenaeus stylirostrisUSING A PREPARED DIET AS ALGAL SUBSTITUTE AND FORArtemiaENRICHMENT2
Authors: Léger Philippe , Bieber Glen F. , Sorgeloos Patrick
Published: August 2010

The importance of highly unsaturated fatty acids (HUFA) such as 20:5ω3 and 22:6ω3 has been investigated for the larvae of the blue shrimpPenaeus stylirostris. HUFA‐rich or HUFA‐enrichedArtemianauplii yielded higher production results in the hatchery than HUFA‐poorArtemia, especially when yeast was used as a substitute for algae during the early larval stages. Best results were obtained when a HUFA‐rich formulated diet was used as a supplement to the yeast and as an enrichment for theArtemianauplii. Differences in production results could be attributed to the HUFA content in living and non‐living larval diets.
THE EFFECT OF CLAM SIZE, NET SIZE, AND POISONED BAIT TREATMENTS ON SURVIVAL OF HARD CLAM, Mercenaria mercenaria, SEED IN FIELD PLOTS
Authors: Kraeuter John N. , Castagna Michael
Published: August 2010

Economics dictates that the seed of the hard clam, Mercenaria mercenaria, be grown only to moderate sizes before field planting. Survival in the field nursery area is a function of multiple interactions with size specific predation playing the dominant role in survival of planted seed clams. This investigation compares field survival of five sizes of clam seed (4 to 14 mm) with two protective mesh sizes (6.25 mm and 12.5 mm openings) and poisoned bait treatments (malathion injected fish). Baffle treatments for two seed sizes are included to relate these studies to those previously published. Analysis indicates significant increases in survival with the use of poisoned bait and mesh size treatments for small seed sizes. No effect of poisoned bait was found for large seed sizes. Statistically significant interactions occur between seed size and mesh combinations. Comparisons are made with other data to indicate the significance of these interactions.