bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxicity of Chelated Copper to Juvenile Red Drum Sciaenops ocellatus1
Authors: Peppard Eileen M. , Wolters William R. , Avault James W. , Guthrie Perry W. 
Published: April 2007

AbstractAcute toxicity of chelated copper to juvenile red drum (x̄= 3.1 g) was determined in a static test at 25 C and 8 ppt salinity. The 12, 24, 48, 72, and 96 h LC50s were 1.90, 0.84, 0.75, 0.64, and 0.52 mg/L copper, respectively. Effects of temperature and salinity on the 96 h LC50 (0.5 mg/L copper) for juvenile red drum (x̄= 5.0 g) were tested at two temperatures, 25 and 30 C, and three salinities, 0.5, 8, and 30 ppt. Temperature significantly affected mortality; mortality in 0.5 and 8 ppt salinities was significantly higher at 30 C than at 25 C. An increase in salinity significantly reduced the mortality of juvenile red drum. Total mortality occurred in 0.5 ppt salinity within 48 h at 25 C and within 12 h at 30 C. Total mortality occurred in 8 ppt salinity within 72 h at 25 C and within 48 h at 30 C. No mortality occurred during 96 h in 30 ppt salinity at 25 C or 30 C.
Optimum Feeding Rate of the Rotifer Brachionus plicatilis on the Marine Alga Nannochloropsis sp.
Authors: Ahmad Abu Talib , Yamasam Shigehisa , Hirata Hachiro 
Published: April 2007

AbstractThe optimum feeding rate of the rotifer Bruchionus plicutilis was investigated to determine the best conditions for growth of the rotifer, and also in order to maintain good water quality of the culture. Fifty rotifers of a large size strain were cultured individually at five food density levels of Nannoehloropsis sp. (0.5 ± 106, 1.5 ± 106, 3 ± 106, 5 ± 106, and 8 ± 106 cells/ml). At each level, daily survival and offspring production were recorded until the death of the final individual. The data obtained were analyzed by the life table method. The maximum value of three growth indices (the net reproduction rate, mean life expectancy at age 0, and intrinsic rate of increase) was obtdned at the food density of 1.5 ± 106 cells/ml. The ration size was calculated to be 325% (dry weight)/ day, which is equivalent to about 70% of the saturated feeding rate. It was suggested that the feeding rate should be controlled to lower than the saturated value for an efficient mass culture.
Spermatophore Generation Times inPenaeus setiferus, P. vannamei, andP. stylirostris
Authors: Leung‐Trujillo Joanna R. , Lawrence Addison L. 
Published: April 2007

AbstractSpermatophore development times were studied in three species of penaeid shrimp,Penueus setifcrus, P. vannumei, andP. stylirosrris. In the terminal ampoule, the progression of spermatophore formation occurred in 4 stages (I‐IV). The duration of each stage varied with species and ablation state. In unablated males, with spermatophores manually or electrically removed, structnrally complete spermatophores containing high numbers of morphologically normal sperm were formed in 2–4 days forP. vannamei, 4–6 days forP. stylirostrisand 5–7 days forP. setiferus. Unilateral eyestalk ablation ofP. setiferusaccelerated spermatophore production time by approximately 2 days, and significantly increased spermatophore weight and sperm count without affecting sperm quality.Spermatophore removal techniques had little effect on development time inP. vannamei. However, inP. setiferus, new spermatophores were produced faster in males mating naturally than in those males whose spermatophores were removed electrically.
Evaluation of the Dietary Iron Requirement of Penaeus vannamei
Authors: Davis D. Allen , Lawrence Addison L. , Gatlin Delbert M. 
Published: April 2007

AbstractTwo experiments were conducted to evaluate the dietary iron requirement of juvenile Penaeus vunnamei. Prior to initiation of 28 day (Experiment I) and 35 day (Experiment II) feeding trials, 17–20day‐old postlarvae were fed the basal diet lacking iron supplementation but containing 12 mg Fe/kg for seven days. After conditioning, juvenile shrimp (mean weight: 0.038 g Experiment I, 0.047 g Experiment II) were fed one of four diets supplemented with 0, 20, 40 or 80 mg Fe/kg from ferrous sulfate heptahydrate. Final weight gain of shrimp ranged from 1.03 to 1.28 g in Experiment I and 1.62 to 1.94 g in Experiment II. Although percent weight gain was in excess of 2700% in Experiment I and 3400% in Experiment II, there were no significant differences in growth or survival of shrimp fed the different levels of iron. Iron levels of the hepatopancreas and carapace increased linearly with dietary iron; however, there were no significant differences in the iron content of muscle tissue. Based on these results, the iron content of the basal diet appeared to satisfy physiological needs of the shrimp. Therefore, practical diets containing protein sources of animal origin which are rich in iron should not require iron supplementation.
Economic Effects of Intensification of Baitfish Production
Authors: Pounds Gayle L. , Engle Carole R. , Dorman Larry W. 
Published: April 2007

AbstractThis study analyzed the economic effects of intensifying baitfish production. An economic engineering approach was utilized to develop enterprise budgets for baiffish production that were used to conduct an economic analysis. All indicators utilized, including net returns, internal rate of return, and payback period, indicated dramatic improvement in the economics of baitfish production with yield increases. There were strong economic incentives to increase yield, and minnow production at industry average yield was only marginally profitable under certain scenarios and unprofitable under others. Yields of 600 kg/ha would generate adequate revenue to compete with other aquaculture alternatives in terms of net returns as well as generate M internal rate of return that would outperform current long‐term interest rates.
Enhancement of the Fatty Acid Composition of the Nematode Panagrellus redivivus Using Three Different Medial
Authors: Rouse David B. , Webster Carl D. , Radwin Ismail A. 
Published: April 2007

AbstractThe free living nematode Panagrellus redivivus has shown promise as a live food for marine shrimp and fish. This study evaluated the effect of three media on the fatty acid (FA) profile of nematodes. The media tested were: wheat flour (WF), wheat flour plus yeast (WFY), and wheat flour plus yeast plus fish oil (WFFO).The total lipid content of nematodes grown on WFFO (14.9%) was significantly higher than the lipid content of nematodes grown on WF (2.7%) and WFY (4.4%). The lipid of nematodes grown on WFFO also contained a higher percentage of n‐3 highly unsaturated fatty acids (HUFA) (11.2%), especially 20:5(n‐3) (7.4%) and 22:6(n‐3) (3.3%), than nematodes grown on WF (4.8%) and WFY (5.7%). Nematodes grown on WFFO medium had similar lipids as Artemia, especially desirable n‐3 HUFA's.Total daily yield of nematodes was highest on WFY. There was no difference in yields of nematodes on WF and WFFO. This study has shown that the nutritional value of nematodes can be influenced by the media on which they are cultured. With a proper medium, cultured nematodes can provide the inexpensive, consistently nutritious live food that can be considered for larval culture of marine crustaceans and fish.
Effect of Dietary Protein Concentration on Nitrogenous Waste in Intensively Fed Catfish Ponds
Authors: Li Menghe , Lovell Richard T. 
Published: April 2007

AbstractChannel catfish were fed five diets containing 24, 28, 32, 36 or 40% protein in intensively stocked earthen ponds over a 141 d growing season. Mean standing crop at harvest was 7,559 kg/ha, and maximum daily feed allowance was 105 kg/ha. Dietary protein concentration had a negative linear effect on weight gain. Total ammonia‐nitrogen (TAN) in pond water increased linearly as dietary protein concentration increased and was positively correlated with total protein fed. However, unionized ammonia‐nitrogen (NH3‐N) was not influenced by dietary protein concentration. Dietary protein had a positive linear effect on nitrite‐nitrogen (NO1‐‐ ‐N) concentration, which was positively correlated with total protein fed and TAN. There was no significant correlation between NO2‐‐‐N and fish weight gain, although there was a significant positive correlation between NO2‐‐ ‐N/Cl‐molar ratio in pond water and concentration of methemoglobin in the fish. Results from this study indicate that when the feeding rate is as high as 100 kg/ha/d, or 3,000 kg protein/ha/season, dietary protein concentrations of 36% and above can result in harmful concentrations of NO2‐‐‐N when Cl concentration in the ponds is 2–3 mg/L. Although the NO2‐‐‐N/Cl‐ ratio in the ponds increased to harmful levels with protein concentration of the diets, this might not be the major cause of the reduction in fish growth rate as dietary protein increased because the greatest difference in weight gain occurred at the lower protein concentrations and the greatest difference in NO2‐‐‐N occurred at the higher dietary protein concentrations.
Effect of Salinity on Hatching in Neobenedenia melleni, a Monogenean Ectoparasite of Seawater‐Cultured Tilapia
Authors: Mueller Karl W. , Watanabe Wade O. , Head William D. 
Published: April 2007

AbstractLaboratory experiments were conducted to determine the effect of salinity on embryonic development and hatching in Neobenedenia melleni, a monogenean ectoparasite of seawater‐cultured (37 ppt) Florida red tilapia (Oreochromis urolepis hornorum × O. mossambicus). Eggs, collected from adult monogeneans at 37 ppt, were exposed to different salinities (0, 6, 12, 18, 24, 30 and 37 ppt) for 48, 72 or 96 h. Varying degrees of post‐treatment development and hatching occurred when natural seawater conditions were restored. Hatching success generally declined with decreasing salinity and increasing duration of exposure. Under all durations of exposure, hatching success remained relatively high (≥ 69.6%) at salinities of 24 ppt and above, but declined markedly (≤ 32.5%) at lower salinities. Hatching did not occur in eggs exposed to fresh water (0 ppt) for 72 and 96 h. The most effective treatments in preventing hatching, other than prolonged exposure to fresh water, were 96 h exposures to low‐salinity brackish water. Percent hatch after 96 h exposure to 6, 12 and 18 ppt was 5.5, 11.9 and 5.8%, respectively.
Evaluation of Naturally‐Occurring Organisms as Food for Juvenile Crayfish Procambarus clarkii1
Authors: Brown Paul B. , Wetzel James E. , Spacie Anne , Konopka Allan 
Published: April 2007

AbstractNutritionally important food items for crayfish have been difficult to identify and little information exists for third instar (first‐feeding) crayfish. In this study, three major groups of potentially‐important foods were fed to communally‐reared third instar crayfish (Procambarus clarkii) and weight gain and survival were measured over a 30 day period. Mean weight gain (% increase) of crayfish fed the zooplankton Daphnia magna alone or in combination with other food items, ranged 2, 277–3, 239%, while mean weight gain of crayfish fed unidentified aquatic bacteria, the aquatic macrophyte Myriophyllum spicatus, combinations of bacteria and plant, or a negative control ranged 254–767%. No significant interaction of food items was detected. Bacteria appear to be a utilizable nutritional source for juvenile crayfish, but, using the methods employed in this study, do not support maximum rates of weight gain. Thus, pond management strategies that maximize zooplankton populations at the time of crayfish hatching might be beneficial.
Biology of Idotea baltica in Chondrus Aquaculture1
Authors: Shacklock Peter F. 
Published: April 2007

AbstractThe marine isopod, Idoreu baltica, was studied in conjunction with Chondrus crispus aquaculture to provide information necessary for managing populations of grazers in the biological control of algal weed species. Feeding rates, growth, and reproductive activities varied directly with temperature between 10 C and 20 C. The amount of Chondrus consumed at 20 C was approximately double that at 10 C. Female I. baltica released young at about 16 day intervals at 20 C, 25 days at 15 c and 60 days at 10 C. One female grown at 17 C produced a total of 8 broods of young over a 182 day period. The number of young per brood from this female increased from 84 (1st brood) to 310 (7th brood) as she matured. Ectocurpus, Enteromorpha and Palmaria were grazed preferentially over Chondrus and Gracilaria; a preference for haploid phases of Chondrus over diploid phases was also noted. Cannibalism was prevalent and it is suggested that this behavior might fulfill a dietary requirement.
Experimental Studies of Feeding in Larval Red Drum
Authors: Holt G. Joan 
Published: April 2007

AbstractThe red drum (Sciaenops ocellatus) is the only marine fish species in commercial culture in the US. Red drum can be induced to spawn on demand at any time of the year and the young grown to marketable size in indoor raceways or in ponds. Although many eggs are produced (up to 1 million per spawning pair), grow‐out through the larval stage remains a bottleneck in commercial production. Most larvae for commercial use are grown in outdoor ponds where natural blooms of phytoplankton and zooplankton are induced, but pond production is limited seasonally and geographically since red drum larvae require sea water and are intolerant of temperatures below 20 C.It is possible to raise larvae indoors in tanks year‐round by controlling temperature and salinity and by culturing live food, but not in sufficient number to supply commercial fish growers. Experimental studies are being carried out to modify the feeding and rearing systems to improve production of post‐larvae. Of utmost importance is the development of a complete diet independent of live foods. Results of studies of highly unsaturated fatty acid requirements, digestive system development and activity levels of digestive enzymes are being incorporated into the development of an improved diet for red drum larvae.
The Development of a Functional Digestive System in the African Catfish Clarias gariepinus (Burchell)
Authors: Verreth Johan A. J. , Torreele Els , Spazier Eljallil , Van der Sluiszen Ad , Rombout Jan H. W. M. , Booms Ronald , Segner Helmut 
Published: April 2007

AbstractThe morphological and physiological development of the intestine, stomach, liver and pancreas of the African catfish, Clarius guriepinus (Burchell 1822), was investigated from hatching until 9 days after the start of exogenous feeding by histological, histochemical and immunohistochemical procedures. During the yolk sac period, lasting 48 hours at 30 C, the digestive system develops from a rather undifferentiated system into a distinct liver and pancreas and a segmented intestine (parts I to III). Insulin and glucagon producing cells were clearly found in the endocrine pancreatic islets from 14 hours after hatching onwards, while at the start of exogenous feeding, the exocrine pancreas showed an intense zymogen colouration. Exogenous feeding started three days after fertilization, i.e., 48 hours after hatching. At that moment, the rearing temperature was lowered to 27.5 C. The first day of feeding was referred to as day zero, changing into day 1 when the first 24 hours of feeding were completed. From the start of exogenous feeding onwards, aminopeptidase, non‐specific esterase and ATP‐ase were detected in the digestive system. Morphologically, the stomach was completed at day 4 of exogenous feeding. Gastric acid secretion started on day 4 and lead to a pH below 3.3 in the stomach on day 5. During the first four days of exogenous feeding, C‐t‐gastrin immunopositive cells were found throughout the gut, including the gastric epithelium. After day 4, the C‐t‐gastrin cells were only detected in the anterior intestine. The completeness of the stomach development was also marked by the appearance of non‐specific esterase activity in the stomach epithelial cells on day 5. All data together clearly indicate that in Clarius gariepinus, the ontogeny of a functional digestive system has been completed on day 5 after the start of exogenous feeding, marking thereby the end of the larval period.
Evaluation of Live Feeds for Larval and Postlarval Mahimahi Coryphaena hippurus
Authors: Kraul Syd , Nelson Alan , Brittain Karen , Ako Harry , Ogasawara Amy 
Published: April 2007

AbstractLive hatchery feeds were assayed for fatty acids (FA), amino acids (AA), and their ability to support growth and survival of larval and postlarval mahimahi Coryphaena hippurus at two different hatchery stages. Euterpina acuritrons copepods (C), mahimahi yolk‐sac larvae (YSL), Artemia parthenogenica brine shrimp nauplii (BSn), A. parthenogenica juveniles (BSj), and Brachionus plicatilis rotifers (R) were assayed, using several enrichment media. There was little difference in AAs among feeds.Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were about 10 times higher in YSL than in their feeds. This explains previous findings where first stage larval survival (0–9 days) was not affected by feed HUFA levels. Second stage survival was significantly higher when larvae were fed copepods. Enrichment with 100 ppm SuperSelco greatly improved the survival of larvae that were fed brine shrimp. The even higher omega‐3 fatty acids found in copepods appear to be important for survival of larvae under more stressful conditions.Brine shrimp juveniles enriched with SuperSelco are a good food for postlarval mahimahi. Yolksac larvae of mahimahi are an even better food, promoting faster growth at less cost, for large scale mahimahi aquaculturists. Different batches of yolksac mahimahi larvae varied by a factor of 10 in their concentration of DHA, but always had the highest level of DHA as much as 40% of total fatty acids (FAs). These “high HUFA” batches of YSL also had the highest levels of EPA and total fatty acids. The data suggest that climate and broodstock age may have considerable influence on larval nutrition.
Evaluation of the Dietary Zinc Requirement of Penaeus vannamei and Effects of Phytic Acid on Zinc and Phosphorus Bioavailability
Authors: Davis D. Allen , Lawrence Addison L. , Gatlin Delbert M. 
Published: April 2007

AbstractExperiments were conducted to determine the dietary zinc requirement of Penaeus vannomri and evaluate the effects of phytate on zinc bioavailability. Prior to initiation of the growth trial, 20‐day‐old P. vonnamei postlarvae (mean weight 0.0032 g) were fed a casein‐gelatin based semi‐purified diet lacking zinc supplementation but containing 18 mg Zn/kg diet for one week. Subsequently, juveniles (mean weight 0.058 g) were fed one of seven diets containing either supplemental zinc (0, 15, 30, 60 mg/kg diet) without phytate or supplemental zinc (0, 60, 200 mg/kg diet) with 1.5% phytate for 33 days. Weight gain was greatest in shrimp fed 15 mg supplemental Zn/kg diet. In the absence of dietary phytate, zinc concentrations in the hepatopancreas of shrimp were maximized when zinc was supplemented at levels greater than or equal to 15 mg Zn/kg diet (33 mg total Zn/ kg). Supplementation of 1.5% phytate to the diet did not have a significant effect on growth or zinc concentrations in the carapace; however, it did depress zinc levels in the hepatopancreas. Supplementation of 200 mg Zn/kg diet was required to overcome the depressed bioavailability of zinc caused by the presence of dietary phytate and return zinc levels of the hepatopancreas to that observed when phytate was not present. Based on apparent digestibility values phytate phosphorus was unavailable to the shrimp and the presence of phytate depressed the bioavailability of phosphorus and zinc.
Evaluation of Beef Liver, Fruits, and Vegetables as Dietary Supplements for Indoor Nursery Culture of Freshwater Prawns Macrobrachium rosenbergii
Authors: Garces Carla L. , Heinen John M. 
Published: April 2007

AbstractFrozen beef liver fed at dietary levels of 5, 10, 15, 20, and 25% (dry weight) to postlarval Mucrobruchium rosenbergii was evaluated as a supplement to Mna Trout Chow No. 2. Final mean wet weights and yields of prawns fed 15, 20, and 25% beef liver were significantly higher than those of prawns that received 5 and 10% levels. Survival rates and food conversion ratios of dry matter fed to wet biomass produced were not significantly different among treatments. The suitability of 47 fresh and frozen fruits and vegetables as dietary supplements was tested. Fourteen fruits and vegetables sank and were readily consumed by prawns, and seven (fresh orange and sweet potato, and frozen banana, carrot tops, butternut squash, yellow squash, and turnip greens) were tested as supplements (10% dry weight of the total ration) to trout chow and 15% beef liver. There were no significant differences (P < 0.05) in final mean weight, survival, yield, or food conversion ratio. Pigmentation of prams fed carrot tops or turnip greens was enhanced. No significant differences in final mean weight, yield, or survival were found when frozen banana was evaluated at levels of 0, 5,10,15, and 20% as a supplement to trout chow and 15% beef liver. Food conversion ratios for prawns fed 15 and 20% levels of banana were not different from those fed 10%, but were significantly higher than for prawns fed the 0 and 5% levels. Thus, a diet of Purina Trout Chow No. 2 plus 15% beef liver gives good results with postlarval M. rosenbergii in aquaria. Largescale testing and an economic analysis are needed to determine if this diet is practical for commercial prawn nurseries.
Evaluation of Distillers Dried Grains with Solubles as an Ingredient in Diets for Pond Culture of the Freshwater Prawn Macrobrachium rosenbergii
Authors: Tidwell James H. , Webster Carl D. , Clark Julia A. , D'Abramo Louis R. 
Published: April 2007

AbstractDistillers dried grains with solubles (DDGS) were evaluated as an ingredient in practical diets for pond culture of the freshwater prawn Macrobrachium rosenbergii. Juvenile prawns averaging 0.66 ± 0.47 g were stocked into nine 0.02 ha ponds at 19,760/ha. Three isonitrogenous diets (29% crude protein) containing 0, 20, or 40% DDGS were fed to shrimp in triplicate ponds. Average yield, survival, individual weight, and feed conversion did not differ significantly (P > 0.05) among treatments. When averaged over the three diets, results were: yield, 833 kg/ha; survival, 75%; individual weight, 57 B; and feed conversion, 3.1. It appears that DDGS is a suitable ingredient for use in practical diets for freshwater prawns at levels of up to 40% of the total formulation, when prawns are stocked at the densities used in this study.