bluuebunny/crossref_metadata_2025 huggingface dataset:
CULTURE OF THE BLACK MANGROVE (Avicennia qerminans) IN A CLOSED SYNTHETIC SEAWATER SYSTEM
Authors: Hoff F. H. , Frakes T. A. , Hoff W. G.
Published: August 2010

Black mangrove (Avicennia germinans) were grown from seed in a closed synthetic seawater system to a maximum height of 165 cm and trunk diameter of 20 mm in 24 months. Plants were maintained in glass aquaria in 63 mm of crushed coral and shell substrate and received continual flow from a 28,387 liter system. Seedlings were planted in aquaria 18, 30 and 46 cm deep but only those in 18 cm aquaria survived. The entire system is housed in a modified greenhouse and only ambient light was provided. Average salinity was 27 ppt (range 17–34 ppt), temperature 26.2°C (range 21.3 to 30°C), pH 8.05 (range 7.8‐8.3), nitrate‐N 52.3 ppm (range 38–66 ppm) and phosphate‐P 0.568 ppm (range 0.078‐1.080 ppm). Additions of a trace metal solution were made during the last 14 months.
CASE STUDY OF TWO SMALL‐SCALE TILAPIA PROCESSING OPERATIONS
Authors: Nelson Robert G. , Behrends Leslie L.
Published: August 2010

Preliminary case studies indicate that a wide range of labor efficiencies may exist among tilapia processing operations. Efficient use of personnel on the processing line seems to be as important as skill or experience in improving labor efficiency. Processing rate and dressout percentage are used with information on costs and prices from the literature to estimate the minimum quantity of tilapia necessary to support a processing plant and the unit cost of processing at that level. The implications are discussed with respect to the integration of tilapia into existing fish farming, processing, and marketing practices in the southeastern United States.
SEASONAL DIFFERENCES IN THE EFFECT OF PHOTOPERIOD ON SURVIVAL AND DEVELOPMENT OF LARVAL AMERICAN LOBSTERS (Homarus americanus)
Authors: Aiken D. E. , Rowe W. J. , Martin‐Robichaud D. J. , Waddy S. L.
Published: August 2010

Previous experiments showed that larval lobsters reared in culture tanks survived better and developed faster in very short days. Further study has revealed that this phenomenon is modified by season of the year. Larvae have been hatched and reared to Fourth Stage at LD 01:23, LD 12:12 and LD 23:01 in standard planktonkriesels at constant 20°C during each month from February through September. In winter and early spring, best survival was obtained with very short photophase (LD 01:23). In May and June, survival was better in the intermediate daylength (LD 12:12). Rate of development to Fourth Stage also was affected by season. Mean time to 80% metamorphosis was shorter in LD 01:23 in spring and in LD 23:01 in late summer. In general, larvae hatched in late summer took longer to reach Fourth Stage than those hatched in spring. However, size at Fourth Stage did not appear to be influenced by either season or photoperiod.
LARGE‐SCALE, COMMERCIAL APPLICATION OF PENAEID SHRIMP MATURATION TECHNOLOGY
Authors: Simon Clyde M.
Published: August 2010

A maturation facility was designed and constructed to provide spawners for the year‐round hatchery operations at a minimum output of 5 million P10postlarvae per month. Maturation is carried out in 3.65‐m diameter tanks stocked with 70–75 brood‐stock shrimp of reproductive size at a 1:1 sex ratio. Females are unilaterally ablated. Tank interiors are black; no substrate is used. Filtered seawater at 28–32 ppt salinity, 27–31°C temperature is continuously exchanged at a rate of 100–250% per day. Only artificial light is available. Photoperiod is 14 hours light, 10 hours dark daily.

Penaeus monodonbrood stock are obtained from the wild and from ponds operated specifically for the rearing of brood stock. Diet in the maturation tanks consists mainly of squid and clams. Spawning histories of individual females are not monitored; the operational unit is the maturation tank, of which 18 were available. Productivity is monitored and evaluated in terms of percent hatch, total numher of nauplii and percent survival to the first protozoeal substage. Eggs with an average hatching rate of 62% are being obtained daily resulting in a yield of 0.4‐1.0 million viable nauplii per day. Details of the design of the facilities and of the methods and operating procedures developed are given, and production results are discussed.
THE REPRODUCTIVE BIOLOGY OF THE RABBITFISH IN HONG KONG
Authors: Tseng W. Y. , Chan K. L.
Published: August 2010

The mariculture enterprise of Hong Kong is expanding and many varieties of fish, among them Siganus canaliculatus, are being cultured in cages. Investigations show that the siganids have a definite spawning period from March to June. This finding is based on such aspects as stage of oogenesis, development of oocyte to maturity and seasonal variation of oocyte maturation. From statistical analysis, a 1:1 ratio has been found between the male and female during reproduction. The fecundity studies showed that about half a million eggs are produced and fecundity varies with fish size. The gonadosomatic index also indicates that March to June is the period of reproduction of S. canaliculatus in Hong Kong waters.
THE POLYCULTURE OFPenaeus stylirostrisSTIMPSON ANDPenaeus aztecusIN TANKS
Authors: Rubino A. J. , Lawrence A. L. , Zein‐Eldin Z. P.
Published: August 2010

Penaeus aztecus, obtained from the wild, and hatchery‐rearedP. stylirostriswere placed together in 65 liter tanks in 5 ratios (0:100, 25: 75, 50:50, 75:25 and 100:0). Two experiments were done. The first experiment consisted of 4 replicates of each ratio at 20°C and 30°C and 2 replicates of each of the 100% tanks at 25°C. Initial size ofP. aztecusandP. stylirostriswere 0.12 and 0.07 g, respectively. In the second experiment initial sizes of the wildP. aztecusand pond‐rearedP. stylirostriswere 1.30 and 0.89 g, respectively. The second experiment consisted of 4 replicates of each ratio at 25°C. The mean weight gain, mortality and biomass (actual and that expected on the basis of monoculture) were calculated.

In the first experiment, the 50% treatment had the highest mean weight gain for both species, In both experiments, decreasing numbers ofP. aztecus(increasing numbers ofP. stylirostris) in a treatment resulted in a better growth ofP. aztecusin the treatment. The survival of both species decreased as the percentage ofP. aztecusincreased. Survival was influenced by temperature, density, and species interactions. The largest difference between actual and expected biomass was found to be forP. aztecusat 30°C, notably in the 75%P. aztecustreatment.

P. aztecusdoes not seem to be influenced by the presence ofP. stylirostrisas much asP. stylirostrisis influenced byP. aztecusin the same tank.
POLYCULTURE OF THE PRAWN, Macrobrachium rosenbergii, WITH FINGERLING AND ADULT CATFISH, Ictalurus punctatus, AND CHINESE CARPS, Hypophthalmichthys molitrix AND Ctenopharyngodon idella, IN EARTHEN PONDS IN SOUTH LOUISIANA
Authors: Miltner M. R. , Granados A. , Romaire R. , Avault J. W. , Ra'anan Z. , Cohen D.
Published: August 2010

A study was conducted to determine the feasibility of growing the giant prawn (Macrobrachium rosenbergii) in polyculture with channel catfish (Ictalurus punctatus) fingerlings and adults. Nursed juvenile prawns, 0.5‐1 g, were stocked in 18 0.04 ha ponds at 2,500/ha. Eight ponds were stocked with 0.05 g catfish fry at 100,000/ha or 200,000/ha; eight ponds received 13 g catfish fingerlings at 3,700 or 7,400/ha. Two ponds received prawns only as a control. Prawn survival from all ponds averaged 96%, and in no case was survival less than 84%. Prawn survival was not affected by the size or stocking density of catfish. Prawn yields averaged 170 kg/ha after a 107‐day grow‐out period. Overall, males averaged 87±25.3 g and females 55±13.9 g at harvest. Prawn yields and male weight at harvest were independent of catfish stocking size and stocking density. Harvest weight of individual female prawns was affected by catfish treatment. Prawn morphotypic profile was independent of catfish stocking treatment. Average adult catfish survival and yield were 52% and 1,305 kg/ha at the high stocking density, and 51% and 735 kg/ha at the low stocking density. Fingerling catfish survival and yield in fry‐stocked ponds averaged 41% and 963 kg/ha at the high density and 50% and 603 kg/ha at the low stocking densities. Poor catfish performance was not believed to be related to the presence of prawns.
THE GROWTH OF Macrobrachium rosenbergii FED COMMERCIAL FEEDS IN POND CAGES
Authors: Stanley R. W. , Moore L. B.
Published: August 2010

A number of commercially available prawn and shrimp diets were tested in situ in response to a Hawaiian prawn industry mandate to conduct such an investigation under experimental conditions. In trial 1, feeds were delivered to juvenile Macrobrachium rosenbergii (initial weight 1.9 g) in cages within a commercial prawn pond. Animals were stocked at a density of 10/m2 and fed at a rate of 5% of body weight daily for 10 weeks. There were 5 replicates in each treatment; group weights were taken. Diets varied in ingredients, leading to varying nutrient composition and degree of water stability. There was no statistical difference among 4 diets in promoting the highest average prawn gain of approximately 9 g. However, one of the 4 diets gave the highest increase in biomass (approximately 80 g). Best growth was seen on 27% protein/low water stability ration, followed in order by more water stable feeds of 41%, 28% and 44% protein. To evaluate the effect of water stability of different quality feeds on prawn production, trial 2 tested 3 commercial aquatic feeds in two forms each: 1) bound and water stable, and 2) unbound and less water stable. Fifty‐fifty combinations of the feeds in the two forms were also used. The trial was conducted as described in trial 1. There was no difference in growth of prawns fed bound or unbound forms of a given diet, nor among those fed the 3 types of feed. Results are applicable to animals of this size, reared in cages at this standing crop and fed at this rate.
CHEMOTHERAPY AND PROPHYLAXIS OF BACTERIAL KIDNEY DISEASE WITH ERYTHROMYCIN1
Authors: Groman David B. , Klontz George W.
Published: August 2010

In recent years there has been a resurgence of research efforts to develop efficacious methods for the prevention and treatment of Bacterial Kidney Disease (BKD), a significant systemic bacterial disease of salmonids. This paper reviews these efforts to date with particular emphasis on the use of erythromycin compounds to prevent BKD episodes in North America and Europe. Topics addressed specifically are: the significance of BKD in salmonid fisheries; a historical overview of antibiotic feeding methods used to prevent and/or control BKD; the use of salt and surfactant bath treatments with erythromycin phosphate (E‐PO4); the use of E‐PO4, injections of adult salmonids; the use of E‐PO4 as an egg water hardening agent; and suggestions for future studies.
CURRENT PROBLEMS IN THE CONTROL OF CHANNEL CATFISH VIRUS
Authors: Amend Donald F. , McDowell Terry
Published: August 2010

The only known methods of identifying stocks of fish which have been exposed to the channel catfish virus (CCV) is by previous history and possibly by testing the fish for serum neutralizing antibody (SNA) to CCV. Three catfish farms in California with no history of CCV had broodfish with positive SNA. Weekly monitoring of dead fry for CCV at two of the farms resulted in isolation of CCV even though daily mortality was low and ranged from about 0.1% to about 5%. In those ponds where 0.1% mortality occurred, no SNA positive fish were found in survivors 89 days following isolation of the virus, but positive SNA fish were found in ponds experiencing 5% mortality. In another test broodfish were assayed for SNA in the spring and fall to determine if seasonal differences in SNA occurred, but no correlation was established. These tests show that previous history and mortality rates were not a reliable method of determining previous exposure to CCV. Although there was a good correlation between detection of SNA in broodfish and the presence of CCV in fry, more information is needed before SNA tests can be used to accurately predict presence of CCV in channel catfish populations.
TRIPLOIDY IN CHANNEL CATFISH
Authors: Chrisman C. Larry , Wolters William R. , Libey George S.
Published: August 2010

Triploidy was induced in channel catfish (Ictalurus punctatus) by hand stripping eggs from gravid females, fertilization with minced testes from donor males, and cold shocking the eggs at 5°C for one hour beginning 5 minutes post‐fertilization. Hatching success of eggs cold shocked for one hour was 79% compared to 89% in controls. Cold shocks longer than one hour caused 100% mortality. Cytogenetic observations through lymphocyte cultures and direct processing of mitotic cells from kidney tissue confirmed that all controls were diploid (2n=58 chromosomes) and 100% of the one‐hour cold shocked treatment group were triploid (3n=87 chromosomes). Full sibling diploid and triploid channel catfish were reared in round 870‐liter fiberglass tanks indoors with water supply, filtration, and disease treatment common to both tanks. All fish were fed 4 times daily to satiation for the first month, twice daily to 8 months, then once daily thereafter with appropriately sized trout rations (35% protein). Triploids were significantly heavier at 8 months of age and older stages than the diploids (92.9±0.98 g vs 87.8±1.09 g at 8 months) and converted feed more efficiently (1.19 kg feed per kg of gain in triploids vs 1.3 in diploids). Histological analysis of ovaries and testes from 54 fish representing both ploidy levels confirmed the almost complete lack of sexual development characteristic of many triploid organisms.
TEST‐FARMING OF THE GIANT KELP, Macrocystis, AS A MARINE BIOMASS PRODUCER
Authors: Harger B. W. W. , Neushul M.
Published: August 2010

Marine macroalgae grow and produce biomass at a rapid rate. Large‐scale oceanic farms planted with these plants could provide a renewable source of energy and copious amounts of organic feedstocks for the chemical industry, without interfering with food and fiber production on land. Past projections of the potential of large‐scale macroalgal mariculture have been based on estimates of yield rather than actual cultivation trials.

In the last year, we planted one acre with 722 plants arranged in three different planting densities. This was done in order to test our cultivation methods and determine what the yield is from plants grown on a farm. We have studied the effects of transplanting, handling, cultivation, density, fertilization and harvesting on a population of farmed giant kelp plants. Furthermore, we have been able to gain an appreciation of plant‐to‐plant variability in growth rate.

The results of our work to date indicate that kelp plants grown in the sea are amenable to cultivation. They respond to fertilizer applications and show the effects of competition for light when grown at high planting densities. Under optimum growing conditions, some plants are able to produce nearly a kilo of wet biomass per day. In our view, the very encouraging results of this kelp farming effort show that the giant kelp is nearly as productive as some of the most highly productive land plant crops like sugar cane. It should be possible to further increase the yield from this prototype marine farm through improved marine agronomic practices.
NATURAL FOOD WEB CONTRIBUTIONS TO FISH GROWTH IN MANURED PONDS AS INDICATED BY STABLE CARBON ISOTOPE RATIOS
Authors: Schroeder Gerald L.
Published: August 2010

Analyses of the ratios of stable carbon isotopes (reported as δC) were compared for natural foods and a polyculture of fish grown in manured, warm freshwater ponds. In the following order, fish species δC indicated an increasing dependence for fish growth on the photosynthesis (autotrophic) based food web and a corresponding decreasing dependence on the manure (heterotrophic) based food web: grass carp, common carp, tilapia hybrids, silver carp.
REVIEW OF RECENT BIVALVE CULTURE METHODS1
Authors: Castagna Michael
Published: August 2010

In 1879 William K. Brooks demonstrated that spawn could be taken from oysters, fertilized and grown in much the same manner as fish eggs in a hatchery. The field of bivalve culture progressed slowly in the next 75 years. During the past 28 years commercial bivalve culture has developed and with it a number of innovative methods. The history and state of the art in bivalve culture are discussed. Culture techniques reviewed include selection of spawners for fast growing offspring, conditioning and holding of spawners, triggering mechanisms for spawning, selection of eggs, larval culture, metamorphosis, and juvenile grow‐out. Methods of growing food organisms and research into dietary requirements are discussed. Field grow‐out is also discussed.
EFFECTS OF SALINITY AND WATER TEMPERATURE ON THE SURVIVAL AND GROWTH OF BROWN‐SPOTTED GROUPER LARVAE (Epinephelus tauvina, SERRANIDAE)
Authors: Akatsu S. , Al‐Abdul‐Elah K. M. , Teng S. K.
Published: August 2010

Effects of salinity on the survival and growth of Epinephelus tauvina larvae were tested at 39, 25, 25 to 39 (increasing at a rate of 4–5 ppt/week) and 39 to 25 ppt (decreasing at a rate of 4–5 ppt/week). NO significant differences in survival and growth were observed among the range of salinities tested during the early larval stages (newly‐hatched to 21‐day‐old). However, for the later larval stages (21–40 day old), significantly higher survival and growth were recorded at a constant salinity of 25 ppt. Salinity tolerance limits of newly‐hatched larvae were also investigated. Time to LH50 (median lethal hour) was recorded to be around 14, 51, 153, 144, 131, 118, 103 and 82 hours after stocking for larvae tested at salinities of 0, 4, 8, 12, 16, 24, 32 and 40 ppt, respectively.

Larval survival and growth were tested in 39 ppt salinity at temperatures of 18, 23, 27, 28, 29 and 31°C for newly‐hatched to 12‐day‐old larvae and 28, 29 and 31°C for 19–33 day old larvae. Best survival and growth were recorded at 27–29°C for larvae between newly‐hatched to 12‐day‐old and at 30–31°C for larvae of 19–33 days old.
CORRELATIONS AMONG MOFPHOMETRIC TRAITS OF FINGERLING CATFISHES AND THE RELATIONSHIP TO DRESSING PERCENTAGE AT HARVEST
Authors: Dunham R. A. , Benchakan M. , Smitherman R. O. , Chappell J. A.
Published: August 2010

Blue (Ictalurus furcatus), channel (I. punctatus), white (I. catus) and hybrid catfish grown under similar conditions to a size of 30 g differed in their body conformation (head length, head width, head depth, body depth, caudal peduncle depth and caudal peduncle width to total length ratios; P <.01) and dressing percentage (P < .05). Strains of channel catfish also differed from each other in their body conformation (P < .01) and dressing percentage (P < .05). Body conformation at 30 g was correlated to dressing percentage at 500 g (P < .01). Head width, caudal width and body depth had the largest effects upon dressing percentage (P < .05). Blue catfish, Auburn and Rio Grande strains of channel catfish had higher dressing percentage (P < .05) than the hybrids, white catfish and four remaining channel catfish crosses. Auburn x Rio Grande channel catfish crossbreds had larger (P < .01) heads, caudal peduncles and body depth than their parents, but the Marion x Kansas crossbred channel catfish did not have larger values than their parents. It appears that overdominance for body conformation was prevalent in intraspecific crossbreds. Morphologies of channel‐blue hybrids were between those of their parent species. The correlations between morphometric traits were different (P < .01) among the 10 genetic groups.
HARVESTING MICROALGAE WITH CHITOSAN
Authors: Lavoie A. , de la Noüe J.
Published: August 2010

We have studied the use of chitosan as a non‐toxic flocculant to concentrate freshwater cultures of microalgae; these are part of a biological tertiary treatment system of urban wastewaters intended to produce biomasses for animal feeding. The sedimentation rate measured at increasing concentrations of chitosan showed that, under appropriate conditions (pH, stirring, etc.), a recovery of 95% or more of the algae was obtained at chitosan concentrations lower than 40 mg/liter. This result was obtained with temperatures ranging from 5 to 25°C and with an algal biomass concentration of 100–150 mg dry weight/liter. Results are also presented for biomass concentrations up to 1 g dry weight/liter. On the basis of these results, economic feasibility is examined by comparison with synthetic polyelectrolytes which appear to be the only other flocculants leading to a similar efficiency. Extension of the process to marine algae is also presented.
FISH SILAGE IN AQUACULTURE DIETS
Authors: Hardy Ronald W. , Shearer Karl D. , Stone Fred E. , Wieg Dave H.
Published: August 2010

Fish silage was made from ground, whole Pacific whiting by using 2% sulfuric acid and 0.75% propionic acid by weight as the acidulent. After 3, 6, and 20 days, silage was removed, neutralized with calcium hydroxide, and drum‐dried. Two additional silage products were made from un‐neutralized 20‐day silage and silage neutralized with sodium hydroxide. Vacuum‐dried Pacific whiting meal was used in the control diet. Dry pelleted diets were made using the Abernathy diet formulation S8‐1, modified by replacing the fish meal with either drum‐dried silage or vacuum‐dried Pacific whiting meal.

After 12 weeks, no significant differences were observed in growth or feed conversion between rainbow trout fed either the control diet or diets containing 3‐ or 6‐day‐old silage. Growth and feed conversion were significantly affected by feeding diets containing silage that had been allowed to hydrolyze for 20 days. No differences in growth were observed between groups of trout fed diets containing 20‐day unneutralized silage, or silage neutralized with calcium hydroxide or sodium hydroxide. Acidification of the control diet significantly affected growth and feed conversion. Neutralization of the acidified control diet with calcium hydroxide restored growth and feed conversion.
PRODUCTION TRIALS OF PRAWNS COMPARING A MARINE RATION, CATFISH DIET AND AGRICULTURAL RANGE PELLET
Authors: Perry W. Guthrie , Tarver Johnnie
Published: August 2010

Supplemental prawn feeds were investigated in 1982 and 1983 at the Rockefeller Wildlife Refuge in southwest Louisiana. Brackish water ponds were stocked with postlarvae at 4.4/m2 and production compared among prawns fed: a commercially produced marine ration (25% protein); catfish ration (30% protein); or agricultural range pellets (10% protein).

Prawns fed marine ration achieved the largest size and greatest biomass during both years. Excluding ponds which experienced survival less than 60% due to low oxygen, production of marine ration fed prawns ranged from 556 to 828 kg/ha (av. 704 kg/ha) in 1982 and 704 to 808 kg/ha (av. 733 kg/ha) in 1983. Production in ponds receiving catfish pellets ranged from 483 to 780 kg/ha (av. 588 kg/ha) and prawns fed crushed range pellets had production of 613 kg/ha. Average size of prawns receiving marine ration was 24 g in 1982 and 20 g in 1983. Those fed catfish ration averaged 17 g and range pellet produced prawns averaging 17 g. Food conversion factors were 0.9 and 1.1 for marine ration in 1982 and 1983, respectively; catfish ration and range pellets resulted in average factors of 1.0 and 1.1, respectively.

Dissolved oxygen was a continuing problem throughout the study in most ponds. The ponds which received range pellets displayed the poorest water quality.
CONTROLLED SPAWNING OF F1 HYBRID STRIPED BASS (Morone saxatilis X M. chrysops) AND REARING OF F2 PROGENY1
Authors: Smith Theodore I. J. , Jenkins Wallace E.
Published: August 2010

F1 hybrid bass (striped bass female x white bass male) were matured under controlled photoperiod and temperature regimes. These fish were spawned, using human chorionic gonadotropin (HCG), about 3 months earlier than normally occurs for striped bass in South Carolina. This was accomplished by compressing the natural annual cycle to 9 months. Under controlled conditions, fish previously spawned were reconditioned and respawned in 9 months. When injected with HCG, paired male and female F1 hybrids were able to spawn in tanks.

Hatch rate was low (10%) in the F1 x F1 cross. Further, the F2 larvae exhibited a high degree of growth variation and cannibalism which is common among striped bass larvae. Larval F2 hybrids, stocked at an initial density of 73,510 fish/m3, grew to a mean size of 41.9 mm TL (range 32.0–52.0 mm) in 46 days. Juvenile F2 hybrids, mean weight 12.8 g, were stocked in a controlled recirculating water system at a density of 31/m3. During 189 days, these fish grew to a mean size of 222 g and exhibited a survival of 92.5%.
NUTRITIONAL REQUIREMENTS OF TURBOT (Scophthalmus maximus): I. A PRELIMINARY STUDY OF PROTEIN AND LIPID UTILIZATION
Authors: Caceres‐Martinez C. , Cadena‐Roa M. , Métailler R.
Published: August 2010

Twelve groups of 10 g turbot were fed ad libitum for 42 days. Each group was given a diet containing 37.5, 48.3, 59.2 or 69.8% protein, and 10, 15 or 20% lipid. Food consumption was similar for all diets. Specific growth rate (SGR) increased and feed conversion (FC) decreased with increasing dietary protein content. The best SGR (2.5%) and the best FC (0.57) were obtained with the 69.8% protein‐10% lipid diet. Lipid had a negative effect on growth and food conversion except for low protein diets. Carcass protein and lipid content were not influenced by diet composition. Liver lipid content was nearly constant and showed no trend in relation to the diet composition for 15 and 20% dietary lipid. The fish fed the 10% lipid diet showed higher liver lipid content. Liver glycogen increased with decreasing dietary protein content. High dietary protein levels enhanced daily tissue protein deposition. With the exception of the 37.5% protein‐20% lipid diet, which showed the best protein efficiency ratio (PER=3.1%) and the best protein utilization coefficient (PUC=50%), all the other diets gave similar PER and PUC values, from 2.2 to 2.6% and from 36 to 43%, respectively.
REVIEW OF BIOLOGY AND CULTURE OF ATLANTIC (Acipenser oxyrhynchus) AND SHORTNOSE STURGEON (A. brevirostrum)1
Authors: Smith Theodore I. J. , Dingley Edward K.
Published: August 2010

The Atlantic sturgeon,Acipenser oxyrhynchus, once supported major fisheries along the entire Atlantic coast but today only remnant populations remain. In Canada and in several Atlantic coast states commercial fishing still occurs but landings are about 3% of former levels. In contrast, the shortnose sturgeon,A. brevirostrum, is listed as an endangered species in the United States and is considered rare or endangered in Canada. Commercial harvesting does not occur but there is substantial interest by utility companies and other industrial operations due to its classification as an endangered species. Culture programs were initiated during the last quarter of the 19th century in an effort to replenish the failing sturgeon fisheries. The first North American species to be spawned was the Atlantic sturgeon in 1875. Subsequent work with this species, as well as with the lake sturgeon,A. fulvescens, and the shortnose sturgeon, identified two major problems: an insufficient supply of simultaneously ripe males and females, and fungal destruction of the incubating eggs. By 1912, all culture efforts had been abandoned.

Renewed interest in the culture of North American sturgeons began in the mid‐1970's. Success has been obtained in spawning all species and currently the white sturgeon,A. transmontanus, is being commercially cultured in California. Additional work, however, is needed to develop a suitable hatchery and grow‐out technology for Atlantic and shortnose sturgeon.
SPOTTED SEATROUT FINGERLING PRODUCTION IN SALTWATER PONDS
Authors: Porter Catherine W. , Maciorowski Anthony F.
Published: August 2010

Spotted seatrout (Cynoscion nebulosus) fingerling production in 3 0.1‐ha fertilized saltwater ponds (568 kg/ha cottonseed meal, 3.3 1/ha phosphoric acid, 1.8 kg/ha urea) was compared to 3 identically fertilized ponds each receiving 4 billion brine shrimp nauplii/ha as a forage base supplement. No brine shrimp were recovered in biweekly zooplankton samples or fingerling stomachs, and no significant differences were evident for growth, survival or production between treatments. After 22 days mean (±S.D.) total length (TL), weight, and percent recovery of fingerlings from the six ponds was 39 ± 2 mm, 0.58 ± 0.10 g, and 8.4 ± 2.2%. Average (±S. D.) production was 46.9 ± 7.2 kg/ha and 2.1 ± 0.3 kg/ha/dat. Zooplankton populations were similar in all ponds with rotifers, mixed copepod nauplii, copepods, and polychaete larvae predominating in decreasing order of abundance. Copepods were the major food organism for all size classes examined, ranging from 59–100% of stomach contents. Although not enumerated in zooplankton samples, insects (> 95% Corixidae) accounted for approximately 34% of stomach contents of 30–49 mm fingerlings. Soptted seatrout percent survival and production (kg/ha/day) were increased 2.8 and 12.5 times, respectively, over previous studies. Improved pond yields resulted from combined organic and liquid inorganic fertilizers, and an increased time interval for zooplankton development between pond preparation and fry stocking.
PARASITES OF CULTURED EELS1
Authors: Field Donald W. , Eversole Arnold G.
Published: August 2010

Glass eel and elver stages of American eel (Anguilla rostrata) collected from Cooper River were stocked separately in ponds at a commercial aquaculture facility near Georgetown, South Carolina, in April 1981. Monthly samples of 15 glass eels and 15 elvers were examined for parasites from May 1981 through July 1982. Cultured glass eels (n=225) harbored 5 species of parasites and cultured elvers (n=225) 11 species. Myxidium giardi was the most frequently encountered parasite in cultured glass eels (43.6%) and elvers (60.4%). The percent occurrence of M. giardi was significantly (P < 0.05) greater in cultured elvers.

Occurrence (%) and intensity (parasites/infected eel) of Trichodina sp., the second most frequently encountered parasite, was 10.7% and 3.8 for cultured glass eels and 17.7% and 5.0 for cultured elvers. Occurrence and intensity of Trichodina sp. remained below levels found on wild elvers and elvers treated prophylactically with 100 mg/liter formalin for one hour before stocking ponds. Two species (Henneguya sp. and Ichthyophthirius multifilis) not found in wild eels occurred in cultured elvers and 3 new species (Trichodina sp., Bothriocephalus scorpii, and Philonema sp.) not found in wild glass eels were recovered from cultured glass eels. Management implications in accordance with parasite differences between glass eels and elvers are discussed.
INFLUENCES OF CALCIUM AND MAGNESIUM IONS ON EMBRYO SURVIVAL, PERCENTAGE HATCHING AND LARVAL SURVIVAL OF DOLPHIN FISH Coryphaena hippurus L.
Authors: Lee Cheng‐Sheng , Krishnan L.
Published: August 2010

Five kinds of artificial seawater with similar salinity, pH and osmolarity were prepared with different concentrations of calcium and magnesium ions. The five seawaters in this study are: complete seawater, calcium‐free seawater, half calcium‐free seawater, magnesium‐free seawater, and half magnesium‐free seawater.

Dolphin fish (Coryphaena hippurus) spawn in captive tanks without hormone induction. Eggs with developing embryos were removed from the incubation tank prior to hatching and incubated in the media with different concentrations of calcium and magnesium. Survival and hatching percentages of embryonic eggs in different media were recorded and compared. The results showed that both calcium and magnesium are essential for normal development. Reduction or elimination of either of these ions has different effects, resulting in embryonic abnormalities and/or reduced hatching and larval survival.
RECENT ADVANCES IN PENAEID VIRUS DISEASE INVESTIGATIONS
Authors: Lightner D. V. , Redman R. M. , Williams R. R. , Mohney L. L. , Clerx J. P. M. , Bell T. A. , Brock J. A.
Published: August 2010

Of the approximately 30 known viruses affecting crustaceans, at least six viruses are known in cultured penaeid shrimp. New information is presented here on five of the six penaeid viruses. Baculovirus penaei (BP) in penaeids from widely separated geographic locations was compared by transmission electron microscopy (TEM) of BP‐infected hepatopancreatocytes. Regardless of source or host species, the cytopathology and virion morphology was similar, but differences were found in the dimensions of BP nucleocapsids as a function of geographic source. P. monodon‐type baculovirus (MBV) was discovered in P. monodon from Asia, but it has recently been found to also infect cultured p. merguiensis and p. semisulcatus from other sites in Asia and the Middle East, and possibly P. kerathurus in Italy. Cytopathology and histopathology resulting from MEV infection in each of the species appears identical. Infectious hypodermal and hematopoietic necrosis virus (IHHNV), a picorna‐like virus known previously to infect P. stylirostris, P. vannamei, and P. monodon, has been found to experimentally infect P. japonicus, P. duorarum, P. aztecus and P. setiferus. IHHN appears to be widely distributed in culture facilities in the Americas, Asia, and the Pacific Basin. HPV (hepatopancreatic parvo‐like virus) was discovered in 1983, in four species of cultured or captive wild penaeids in Asia and Australia. TEM studies of HPV‐infected hepatopancreatocytes show HPV virions and cytopathology to be identical in the affected species. REO, a reo‐like virus of cultured P. japonicus in France and Hawaii, infects hepatopancreatic epithelial cells and causes chronic disease and high accumulative mortalities in tanks and possibly grow‐out ponds.
THE PRACTICE OF GRASS PRAWN (Penaeus monodon) CULTURE IN TAIWAN FROM 1968 TO 19841
Authors: Chiang Peter , Liao I. Chiu
Published: August 2010

Grass prawn (Penaeus monodon) culture in Taiwan started more than 300 years ago as a by‐product of milkfish (Chanos chanos) culture. Since 1968, however, with the success achieved in larval rearing, prawn farming has developed into a major aquaculture industry.

Fifty farmers were interviewed and the information obtained from them was compiled for this presentation. Prawn hatcheries have achieved a state of overproduction today, as postlarvae prices have been driven below cost due to the high number of commercial hatcheries now in operation. The evolution of culture ponds has also gone from a primitive lowdensity type to a well designed high‐density type. Formulated feed, its use and its role in the continuing development of the prawn industry, harvesting techniques and processing procedures are discussed. Prawn diseases remain a problem for some farms and this investigation suggests that further research is required in this area.

An economic analysis of cost and profit of both family‐run and commercial farms is presented. A list of fixed and variable costs for operating all types of farms is provided and the relationship between each cost and the final profit is evaluated. The problems facing the grass prawn industry in Taiwan today as well as some future prospects are also discussed.
SOME QUANTITATIVE ASPECTS OF REPRODUCTION AND GROWTH OF THE RED ABALONE, Haliotis rufescens SWAINSON
Authors: Ault Jerald S.
Published: August 2010

Reproduction and growth of a laboratory‐held population of red abalone, Haliotis rufescens, collected at Mendocino, California, were studied at the Telonicher Marine Laboratory, Trinidad, California. Specimens were continuously supplied with and consumed bull kelp fronds, Nereocystis luetkeana. Following induction of artificial spawning, specimens were sacrificed at 15‐day intervals to histologically describe and record the timing of gonadal phases, and to measure gonadal growth. A modified Gonad Bulk Index (GBItc) detected temporal changes in gonad volume and was highly correlated with defined stages of ovarian development. For specimens sexually mature when collected, viable gametes were spawned again 75 to 90 days following artificial spawning. Some specimens were spawned 3 times during a one‐year period. The laboratory regime increased somatic growth and fecundity, and reduced the minimum size at spawning relative to equivalent sized specimens from the field. Estimated fecundities for laboratory‐conditioned specimens averaged 260% greater than for field‐conditioned specimens. The minimum size at spawning for laboratory‐conditioned specimens was less than that for field‐conditioned specimens. The ratio of spawners to non‐spawners for specimens less than 100 mm long was significantly higher for laboratory‐conditioned specimens. Laboratory‐conditioned specimens less than 100 mm long had fecundities comparable to field‐conditioned specimens up to 140 mm long. The criterion of gonadal phases developed for laboratory specimens was compared to a field population from the collection area and indicated an annual gametogenic cycle. About 120 days are required for the completion of a reproductive cycle for red abalone in the field. Natural spawning occurred from April through July, with a peak in May. There was no evidence of partial spawning.
POLYCULTURE OF FRESHWATER PRAWNS, TILAPIA, CHANNEL CATFISH AND CHINESE CARPS
Authors: Behrends Leslie L. , Kingsley John B. , Price Albert H.
Published: August 2010

Juvenile freshwater prawns (Macrobrachium rosenbergii), fingerling channel catfish (Ictalurus punctatus), young‐of‐the‐year tilapia (Tilapia spp.), F‐1 hybrid Chinese carp (femaleAristichthys nobilisx maleHypopthalmichthys molitrix), and grass carp (Ctenopharynqodon idella) were costocked into four replicate 0.05‐ha earthen ponds in 1983 and 1984 and cultured for 124–150 days, respectively. Stocking densities of prawns (20,000/ha), tilapia (2,500/ha), and grass carp (120/ha) were held constant during both years. However, in 1984 stocking densities of channel catfish and hybrid carp were reduced to 7,500/ha and 160/ha, respectively. Throughout each study, a commercial floating catfish feed containing 32% protein was broadcast into the ponds daily at 1600 hours. Feeding rates were adjusted daily to a maximum of 56 kg/ha/day in 1983 and 41 kg/ha/day in 1984.

Average net production figures were strikingly similar during both years–3,180 kg/ha in 1983 and 3,150 kg/ha in 1984. Mean feed conversion values for all species combined were 1.4:1.0 and 1.0:1.0 in 1983 and 1984, respectively. Net production and mean individual weights of component species during 1983 were: prawns (445 kg/ha, x = 30 g), channel catfish (1,411 kg/ha, x = 180 g), tilapia (653 kg/ha, x = 284 g), hybrid carp (546 kg/ha, x = 1,186 g), and grass carp (127 kg/ha, x = 1,337 9). Net production and mean individual weights in 1984 were: prawns (287 kg/ha, x = 19 g), channel catfish (1,698 kg/ha, x = 263 g), tilapia (522 kg/ha, x = 291 g), hybrid carp (389 kg/ha, x = 4,430 g), and grass carp (253 kg/ha, x = 2,924 g). Mean survival of component species ranged from a low of 72.9% for tilapia in 1984 to 100% for grass carp in 1983 and 1984.
Strategies for Development of Rotifers as Larval Fish Food in Ponds
Authors: Li Yonghan , Jin Songdi , Qin Jianguang
Published: August 2010

Strategies to sustain rotifer peak biomass, distribution of rotifer resting eggs in the sediment, and relationship between rotifers and larval fish growth were studied in a series of pond experiments. After the ponds were filled with water, herbivorous rotifers (e.g.,Brachionus calyciflorus) developed first, but were gradually replaced by predatory rotifers (e.g.,Asplanchna). Subsequently, herbivorous cladocerans (e.g.,Moinasp) eventually replaced rotifers and dominated the zooplankton community. The occurrence ofAsplanchnaandMoinaindicated the decline ofB. calyciflorus. Peak rotifer biomass developed 8–10 d after the ponds were filled with water at 20–25 C, 10–15 d at 17–20 C, 15–20 d at 15–17 C, 20–30 d at 10–15 C, and >30 d at < 10 C. The abundance of resting eggs in the top 5‐cm sediment varied from 6 to 83/cm2. About 25% of resting eggs were buried in the top 5‐cm sediment but the number of resting eggs decreased with increased sediment depth. Optimum rotifer biomass for silver carpHypophthalmichthys molitrixlarvae stocked at 1,500,000/ha was 20–40 m/gL. High rotifer biomass (>20 mg/L) usually lasted 3–5 d, but could be prolonged by pond fertilization or cladoceran controls. A weekly application of dipterex at 0.05 mg/L reduced cladoceran biomass but enhanced rotifer biomass. Our results indicate with a careful management plan it is possible to synchronize the rotifer development with larval fish stocking.
Ethidium Bromide Nuclear Staining and Fluorescence Microscopy: An Alternative Method for Triploidy Detection in Fish
Authors: Thititananukiji Suttiporn , Vejaratpimol Renu , Pewnim Thanit , Fast Arlo W.
Published: August 2010

Abstract.– Erythrocyte nuclei from normal diploid (2N) and cold‐shocked triploid (3N) Asian catfish Clarias macrocephalus were comparatively stained with fluorescent stain, ethidium bromide and with a bright‐field stain, Giemsa. Stains were applied to dried blood smears on glass slides, with blood taken from fingerling fish without sacrificing the fish. Both stains produced comparable quality visual comparisons, with significant differences (P < 0.001) between nuclear dimensions of 2N and 3N cells. Triploid nuclei were larger and more elongate than diploid nuclei. Karyotypic comparisons revealed that diploid fish had 54 chromosomes, while triploid fish had 81. Ethidium bromide nuclear staining required only 3 min after slides were air‐dried and fixed, while Giemsa staining required more than 50 min.
Intraspecific Differences in Physiological Efficiency of Juvenile Atlantic Halibut Hippoglossus hippoglossus L.
Authors: Imsland Albert K. , Jonassen Thor M. , Stefansson Sigurd O. , Kadowaki Shusaku , Berntssen Marl H. G.
Published: August 2010

We compared growth efficiency, feeding consumption, metabolism, excretion, and energy allocation in populations of juvenile Atlantic halibut from Norway, Iceland, and Canada reared at low (8 C), medium (12 C, 15 C) and high (18 C) experimental temperatures. Our findings show that protein utilization and energy allocation in juvenile Atlantic halibut varies among different populations, as the Norwegian population displayed the highest protein efficiency ratio, protein production value, and energy conversion efficiency compared to the Canadian population, while the Icelandic population showed overall intermediate growth performance. The results do not conform to a simple thermal adaptation model but might represent an example of: 1) local adaptation of fish populations; or 2) countergradient variation where shorter growing season at higher latitudes is compensated with higher physiological efficiency. These findings have implications for halibut culture, particularly in selection work focusing on growth performance.
Effects of Dietary Protein and Energy Levels on Growth and Body Composition of Juvenile Flounder Paralichthys olivaceus
Authors: Lee Sang‐Min , Cho Sung Hwoan , Kim Kyoung‐Duck
Published: August 2010

A feeding trial of three protein levels (30, 40 and 50%) and two energy levels (300 and 400 kcal/100‐g diet) factorial design with three replications was carried out to investigate the proper dietary protein and energy levels for the growth of juvenile flounder Paralichthys olivaceus. Weight gain of fish tended to improve with increasing dietary protein level. Weight gain of fish fed either the 40% or 50% protein diet with 300 kcal/100‐g diet was significantly higher (P < 0.05) than with 400 kcal/100‐g diet. The best weight gain was obtained from fish fed the 50% protein diet with 300 kcal/100‐g diet. Feed efficiency tended to improve with increasing dietary protein level. However, dietary energy level had no significant effect on feed efficiency of fish fed the 30% or 50% protein diet, but that of fish fed the 40% protein diet with 300 kcal/100‐g diet was significantly higher than with 400 kcal/100‐g diet. Protein retention tended to increase as dietary protein level increased and energy level decreased. Lipid content of fish fed the diet containing 400 kcal/100‐g diet was significantly higher than that of fish fed the diet containing 300 kcal/100‐g diet at all protein levels. Fatty acid compositions such as linoleic acid, EPA (20:5n‐3) and DHA (22:6n‐3) offish were directly affected by dietary lipid (squid liver oil and/or soybean oil) used for energy source. Based on the above results, it can be concluded that the proper dietary protein and energy levels for the growth of juvenile flounder are 50% and 300 kcal/100‐g diet, respectively.
Chemical and Physical Properties of Shrimp Pond Bottom Soils in Ecuador
Authors: Sonnenholzner Stanislaus , Boyd Claude E.
Published: August 2010

Chemical and physical analyses were conducted on bottom soil samples from 74 brackish‐water ponds representing 40 shrimp farms in Ecuador. Most ponds had soils with pH > 6 and total carbon concentrations < 2.5%. Carbon was mostly in organic form, for the average concentration of carbonate carbon was 0.06%. The C: N ratio was 8 to 10 in soils with < 2.5% carbon. In ponds built in former mangrove areas, soil carbon was > 2.5% and C: N ratios were 25 to 30. Ponds soils in former mangrove areas also tended to be high in total sulfur and low in pH. Lack of correlation between carbon and sulfur in mangrove soils suggested that most of the sulfur was inorganic and presumably in sulfides. Soils containing above 0.4% free carbonate (as equivalent CaCO3) had pH values > 7. Although carbonate concentration was a major factor controlling soil pH, calcium hardness of pond waters was strongly influenced by salinity (and calcium) in the water supply. Total phosphorus concentrations averaged 898 mg/kg, and dilute acid extractable phosphorus usually accounted for 25–35% of the total. Concentrations of major cations and minor elements varied greatly in soils and exhibited ranges of up to three orders of magnitude. Contrary to opinions of shrimp producers, many pond soils in Ecuador are not acidic and few soils have a high organic matter content. Proper use of soil and water testing could greatly improve the efficiency of liming and other soil management practices.