bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE PRACTICE OF GRASS PRAWN (Penaeus monodon) CULTURE IN TAIWAN FROM 1968 TO 19841
Authors: Chiang Peter , Liao I. Chiu 
Published: August 2010

ABSTRACTGrass 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

ABSTRACTReproduction 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

ABSTRACTJuvenile 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

AbstractStrategies 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.
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

AbstractWe 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

AbstractA 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

AbstractChemical 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.
Economic Interactions Between Feeding Rates and Stocking Densities in Intensive Catfish Ictalurus punctatus Production
Authors: Losinger Willard , Dasgupta Siddhartha , Engle Carole , Wagner Bruce 
Published: August 2010

AbstractFeed represents the largest cost input in intensive catfish Ictalurus punctatus production. Daily feed rations are generally related to stocking densities, up to a point at which high feeding rates begin to affect water quality. There has been no prior research to analyze the economic interactions between feeding and stocking rates. Econometric techniques were used to estimate a Just‐Pope catfish production function, which was used to compute marginal products of inputs, and to identify stocking and feeding rates associated with the boundaries between Stages I, II, and III of the production function. Survey data collected by USDA National Animal Health Monitoring System were used for this analysis. Maximum yield, when accounting for both stocking and feeding rates, occurred at about 30,000 fingerlings/ha. However, profit‐maximizing stocking densities ranged between 16,942 and 21,312 fingerlings/ha, depending upon expected catfish and feed prices. Farmers stocking at higher rates could be attempting to maximize yield instead of profit.
Nutrient Digestibility of Common Feedstuffs in Extruded Diets for Sunshine Bass Morone chrysops♀×M. saxatilis ♂
Authors: Rawles Steven D. , Gatlin Delbert M. 
Published: August 2010

AbstractThe digestibility of nutrients and energy in various ingredients to fish is affected by a variety of factors including ingredient quality and processing. Limited information is available regarding the digestibility of nutrients in feedstuffs for sunshine bass Morone chrysops♀×M. saxatilis♂. This information is particularly needed to improve the accuracy of diet formulations and allow appropriate substitution of feedstuffs. Therefore, a study was conducted with advanced sunshine bass fingerlings (50–75 g) to determine the apparent digestibility coefficients (ADCs) for protein, lipid, carbohydrate, gross energy, and organic matter in a variety of feedstuffs in extrusion‐processed diets. Included in the study were low‐temperature processed menhaden fish meal (Select®), meat and bone meal, fish meal analog (PROPAK™) dehulled soybean meal, cottonseed meal, corn grain, sorghum, wheat flour, wheat middlings, and rice bran. Test diets consisted of a 70:30 mixture of reference diet to test ingredient with chromic oxide (0.8%) as the inert marker. Reference and test diet ingredients were mixed in a commercial ribbon blender, preconditioned and extruded on a Wenger X‐20 to produce a neutrally buoyant pellet (5 mm). The digestibility trials were conducted in six 600‐L rectangular tanks connected as a closed recirculating brackish (5–7 ppt) water system. Diets were randomly assigned to tanks of 45–50 sunshine bass and fed twice daily to satiation. Feedstuffs of high‐protein and high‐lipid content were better digested by sunshine bass than feedstuffs of high carbohydrate or high fiber content. Organic matter digestibility ranged from 42% for both sorghum and corn to 96% and 98% for meat and bone meal and Select™ menhaden fish meal, respectively. Select™ menhaden fish meal and meat and bone meal appeared to be the best Ingredients for sunshine bass diets in terms of overall nutrient profiles and digestibility of nutrients. The fish meal analog did not perform as favorably as the other two animal products. Protein and lipid of cottonseed meal were highly available to sunshine bass with ADCs of 85% and 92%, respectively. Protein digestibility was high for soybean meal (77%), whereas the digestibility of organic matter (51%), lipid (54%), carbohydrate (25%) and energy (56%) in this feedstuff was moderately low. Energy in wheat middlings and wheat also was moderately available at 67% and 59%, respectively. Energy in sorghum and corn was much less available at 44% and 40%, respectively. Digestibility of nutrients and energy in rice bran exceeded 90%. Use of this information should aid the development of more efficient and economical diet formulations for sunshine bass.
Development of Thyroid Follicles and Changes in Thyroid Hormones During the Early Development of Korean Rockfish Sebastes schlegeli
Authors: Kang Duk‐Young , Chang Young Jin 
Published: August 2010

AbstractThe development of thyroid follicles and the change of thyroid hormone concentrations in whole body were examined, and the relationship between thyroid follicle differentiation and growth were also studied during early development of Korean rockfish Sebastes schlegeli. Total length (TL) and body weight (BW) of larva at parturition were 6.3 ± 0.1 mm and 3.6 ± 0.1 mg respectively. The larvae transformed to juveniles from 20 to 30 d after parturition with continuous growth. The thyroid primordium of the rockfish was observed histologically in newly born larvae, suggesting that the thyroid primordium may have been formed during yolk‐sac larval stage after hatching as with other marine telosts. In addition, although the Korean rockfish is a viviparous fish, the developmental features of the thyroid gland in number, size and shape are very similar to the general development features of marine oviparous fish. As the larvae grew, the thyroid follicles of Korean rockfish increased in number, became variable in size, and changed from the normal spheroid/ovoid shape to more irregular forms in shape after parturition, and then concentrated mostly along the areas immediately adjacent to the ventral aorta. In addition, thyroid cell height and thyroid hormone concentrations were related with physiological activity at a specific developmental stage.
Effect of Dietary Charcoal and Wood Vinegar Mixture (CV82) on Body Composition of Olive Flounder Paralichthys alivaceus
Authors: Yoo Jin Hyung , Ji Seung Cheol , Jeong Gwan Sik 
Published: August 2010

AbstractThe effects of dietary charcoal and wood vinegar mixture (CV82) were determined on growth, body composition, and vitality of olive flounder Paralichrhys alivaceus. Five experimental diets were formulated to contain 0% (control), 0.5%, 1.0%, 1.5%, and 2.0% CV82. Weight gain was lowest in the control diet group (47.7 g) and highest in the 1.0% CV82 group (53.0 g). Feed efficiency was lowest in the control diet group (87.3%) but significantly higher in the 0.5% CV82 diet group (95.8%), (P > 0.05). The condition factor and hepatosomatic index were not affected by the dietary level of CV82. Moisture and crude protein content did not significantly differ among the treatments. However, crude lipid was lower in the 1.0% and 1.5% CV82 diet groups of 3.4% and 3.5%, respectively. Serum glutamic oxaloacetic acid and glutamic pyruvic transaminase activities decreased significantly with increasing dietary CV82 level. Therefore, these results suggested that the suitable dietary CV82 level could be between 0.5% and 1.0% in olive flounder for the maximum weight gain, feed efficiency, and vitality.
Larval Development and Rearing of Longtooth Grouper Epinephelus bruneus in Jeju Island, Korea
Authors: Song Young Bo , Oh Seong Rip , Seo Jong Pyo , Ji Bo Geun , Lim Bong Soo , Lee Young Don , Kim Hyung Bae 
Published: August 2010

AbstractEggs and sperm were obtained from a female (6.3 kg/BW) and a male (8.4 kg/BW) longtooth grouper Epinephelus bruneus following HCG injection in July 2003. The eggs were fertilized artMcially with the sperm and incubated in one of two 50‐m3 tanks after washing the fertilized eggs. The fertilized eggs were 830–950 pn (average 900 ± 2 μm) in diameter and the respective fertilization and hatching rates were 97.7 ± 0.6% and 96.8 ± 0.5% at a water temperature of 25.0 ± 0.5 C. With this regime, the survival rate by day 93 was 7.5% in the 50‐m3 tank. The elapsed time from hatching to opening the mouth was 3 d at 25 C. The initial mouth size (z) of the larvae was 0.22–0.23 mm. The newly hatched larvae were 2.02 ± 0.02 mm TL; this increased to 4.12 ± 0.09 mm TL by day 11. By day 54, the larvae had metamorphosed into juveniles and reached 41.12 ± 1.20 mm TL, and by day 93 the juveniles reached 93.78 ± 1.98 mm TL. In all, 49.5% of the larvae were malformed and the type of malformation was diverse.
Field Efficacy of Florfenicol for Control of Mortality in Channel Catfish, Ictalurus punctatus (Rafinesque), Caused by Infection With Edwardsiella ictaluri
Authors: Gaunt Patricia S. , McGinnis Anissa L. , Santucci Timothy D. , Cao Jean , Waeger Peter , Endris Richard G. 
Published: August 2010

Abstract A field study to assess the efficacy of florfenicol (FFC) against enteric septicemia of catfish (ESC) was conducted with pond‐reared channel catfish fingerlings held in 0.1‐acre earthen ponds. Fish were challenged with Edwardsiella ictaluri in a natural pond outbreak or by cohabitation with E. ictaluri‐infected fish held in netpens. Fourteen ponds were assigned in equal number to two treatment groups, that is, either treated (with 10 mg FFC/kg body weight in medicated feed) or not treated (control) for 10 consecutive d. The threshold for enrollment into the study was 0.3% cumulative mortality attributed to ESC. Treatment was initiated on different dates for each pond because each pond was enrolled when 33 fish/pond were diagnosed with ESC based on clinical signs, lesions, or positive cultures. Mortality was monitored during the 10‐d treatment period and during a 14‐d posttreatment observation period. At the end of the 14‐d posttreatment observation period, all fish were euthanized, and 20 fish from each pond were examined by gross necropsy and evaluated for the presence of E. ictaluri by bacterial culture. The odds of a mortality in the control group were 2.20 times the odds of a mortality in the FFC‐treated group. Significantly fewer (P≤ 0.05) FFC‐medicated catfish died in comparison to unmedicated catfish. The minimum inhibitory concentration of FFC for this strain of E. ictaluri was 0.25 μg/mL in all fish that were assayed. The mean zone of inhibition (Kirby Bauer) was 36.8 mm from E. ictaluri isolates of test fish. There were no FFC treatment‐related lesions seen on gross pathology. FFC was efficacious and safe for control of mortality from E. ictaluri infection in catfish.
Effects of Varying Dietary Protein and Lipid Levels on Growth Performance and Hepatocyte Changes in Juvenile African Cichlids (Pseudotropheus socolofi and Haplochromis ahli)
Authors: Royes Juli‐Anne B. , Murie Debra J. , Francis‐Floyd Ruth 
Published: August 2010

Abstract African cichlids are popular species produced commercially in South Florida for the aquarium trade. In their natural habitat, African cichlids show variations in feeding behavior, ranging from strict herbivory to omnivory to carnivory, and they are therefore excellent model species for nutrition work. The effects of varying dietary protein and lipid levels on the growth performance and hepatocyte changes of juvenile ornamental African cichlids were compared between Pseudotropheus socolofi, an omnivore, and Haplochromis ahli, a carnivore. It was hypothesized that the omnivore would have a lower protein requirement and show a higher incidence and severity of liver pathology when fed a high‐fat diet than the carnivore. Four diets were formulated using two crude protein (CP) levels (35–36% and 55–56% CP) and two lipid levels (8–10% and 19–20%), with resulting gross energy levels between 4000 and 5300 kcal/kg. P.socolofi (0.89 g, 4.1 cm) and H.ahli (2.1 g, 5.7 cm) were fed three times daily at 10% body weight per day (BW/d) for the first 3 wk, then 6% BW/d for the remaining 5 wks. Survival was greater than 86% for all treatments. Average weight gain of carnivorous H.ahli did not differ among the four diets and was greater than that of P.socolofi. P.socolofi grew larger when fed a high‐protein/high‐lipid diet compared to a high‐protein/low‐lipid diet or both the low‐protein diets. However, pathological changes to the liver were observed in P.socolofi fed a diet high in both protein and lipid. Carnivorous H.ahli tolerated higher levels of dietary lipid than the omnivorous P.socolofi. Both species showed significant growth, with no pathological changes occurring in the liver when they were fed a diet of 36% CP, 10% lipid, and 4000 kcal/kg gross energy.