bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Temperature on Feeding Activity of the White River Crayfish Procambarus acutus acutus1
Authors: Seals C. , Eversole A. G. , Tomasso J. R. , Petrosky B. R.
Published: April 2007

Feed consumption by white river crayfish Procambarus acutus acutus in a 56‐d laboratory study increased at a linear rate with water temperature over a range of 5 to 25 C. Feed consumption changed as water temperatures were cycled from 20–8–20 C (0.5 C/d) over a 68‐d period and was the highest at the initial 20 C level and the lowest at 8 C. As water temperature increased, feed consumption rate increased; however, consumption never reached the initial rate at 20 C. Crayfish fed 3% and 6% of body weight were significantly larger than animals fed at 1% of body weight after 8 wk. Feed conversion ratios increased significantly with feeding rate. Based on this laboratory study, white river crayfish feed most effectively when water temperature is ≥ 15 C and the feeding rate is 3% of body weight/d.
Suspended Culture of Doughboy Scallops Mimachlamys asperrima (Lamarck)
Authors: O'Connor Wayne A. , Heasman Michael P. , O'Connor Stephan J.
Published: April 2007

To evaluate the effects of suspended culture on the wet meat weights, reproductive condition and fecundity of doughboy scallops Mimachlamys asperrima, scallops held either in suspended cages or collected from wild stocks on the sea bed were compared over a year. Changes in gonosomatic index (GSI) and macroscopic staging of gonads were similar in both populations; however, after one month, soft body, muscle and gonad weights were heavier in suspended scallops and, with the exception of gonad weight in early summer, remained heavier throughout the year. Fecundity following serotonin‐induced spawning of suspended Mimachlamys asperrima was on average almost twice that of similar sized scallops grown on the sea bed (1.58 and 0.84 million eggs/female, respectively). Suspended scallops surpassed all previous maxima for tissue weights, GSI and fecundity recorded for wild Jervis Bay Mimachlamys asperrima. This indicated that farmers could obtain greater meat yields from suspended rather than reseeded or wild Mimachlamys asperrima and that broodstock to be used in hatcheries may be best obtained from suspended culture.
Natural Spawning and Mass Larviculture of Black Porgy Acanthopagrus schlegeli in Captivity in Taiwan
Authors: Leu Ming‐Yih
Published: April 2007

Abstract.— The black porgy Acanthopagrus schlegeli is one of the most important marine fish cultured in Taiwan. Wild‐caught broodstock were spawned naturally in captivity at water temperatures of 19–26 C in 1989 and 1990. Females produced 352,000 to 957,000 eggs per female during the spawning period. The hatched larvae were reared in 45‐m3 rectangular cement tanks and fed initially on rotifers, Brachionus plicatilis. followed by Artemia nauplii. and finally weaned onto an artificial diet. Larviculture trials to 40 d produced juveniles of 13.1–14.2 mm average total length, at a survival rate ranging from 18.3 to 74.8%. Lordotic deformation was observed in the juvenile stage. However, when an oil skimmer was used to remove the oil film on the water surface, the incidence of lordosis was reduced from 14.4 to 6.1%. High mortality of the larvae occurred during the initial 10–15 d after hatching and cannibalism was observed when larvae reached 7 mm total length. Juveniles grew to size of 83.7–101.4 mm total length with survival rate of 27.9–28.2% in 100 d. The results indicate that the present technique can be used for mass seed production of black porgy.
United States of America Trade in Ornamental Fish
Authors: Chapman Frank A. , Fitz‐Coy Sharon A. , Thunberg Eric M. , Adams Charles M.
Published: April 2007

Ornamental fish production is among the leading cash crops of the United States of America aquaculture economy, and retail value of the fish trade is worth approximately US$l,000 million. However, few studies exist to document this trade. Using import and export documents we report trends in total values for the U.S. trade in ornamental fish. Also, we determined the number and value of the most commonly imported ornamental fish. In 1992, approximately 201 million fish valued at $44.7 million were imported into the U.S. The port of Los Angeles handled 39% of all trade activity, Miami 22%, New York 16%, Tampa 6%, and Honolulu 6%. Freshwater fish accounted for approximately 96% of the total volume and 80% of the value of the imports. Most freshwater ornamental fish were farm‐raised and imported from Southeast Asia. Most U.S. exports of ornamental fish were cultured in the state of Florida. Although saltwater fish had a high market value (20% of the declared value of the imports), the volume of these fish was only 4%. Most imported and exported saltwater ornamental fish were collected from the wild. Of the 1,539 species declared as ornamental fish, 32 species dominated the trade. These were all of freshwater origin. The guppy Poecilia reticulala and neon tetra Paracheirodon innesi were the most popular ornamental fish kept in U.S. households. The average prices paid for imported ornamental freshwater fish were 45 cents for egg layers and 22 cents for live bearers. The results of this study document the importance of the ornamental fish industry and identifies the most valuable species in the trade for potential domestic culture and protection in the wild.
Culture of Juvenile Atlantic Surfclams, Spisula solidissima solidissima and Spisula solidissima similis, in Forced‐Flow Upwellers in a Bivalve Hatchery in Coastal Georgia
Authors: Walker Randal L. , Hurley Dorset H. , Moroney Deborah A.
Published: April 2007

Four experimental growth studies for juvenile Atlantic surfclams, Spisula solidissima solidissima and Spisula solidissima similis, under hatchery conditions were conducted in 10‐cm diameter forced‐flow upweller units. Experiments were designed to determine optimum food ration (2%, 5%, and 8% g dry weight of algae/g wet weight of clam), water culture temperature (20, 25, and 30°C), flow rate (2, 4, and 6 Lpm), and stocking density (7, 14, and 21 g wet weight of clams) for rearing juvenile clams in upweller units. Each experimental trial was performed for a 14‐d period. Nested Analysis of Variance showed that juvenile surfclams Spisula solidissima similis grew significantly faster at a temperature of 20°C and food rations of 5% and 8%. In all four experiments, clam mortalities were not observed except in the temperature experiment, where total mortality occurred for clams cultured at 30°C. Clam growth in biomass and size decreased significantly with increases in culture temperature. For Spisula solidissima solidissima, clam growth was significantly reduced in terms of size and biomass at a flow rate of 6 Lpm. No difference in size or biomass was determined between clams grown at a flow rate of 2 or 4 Lpm. Surfclams at the lowest stocking density of 7 g wet weight significantly increased more in net biomass compared to those at higher stocking densities. Clams were significantly larger in shell length when grown at the two lower stocking densities compared to those at the highest stocking density. Hatchery‐rearing protocol for juvenile surfclams is discussed.
Evaluation of Coastal Bermuda Grass Protein Isolate as a Substitute for Fishmeal in Practical Diets for Channel Catfish Ictalurus punctatus
Authors: Buentello J. Alejandro , Gatlin Delbert M. , Dale Bruce E.
Published: April 2007

In response to concerns over availability and cost of fishmeal for aquaculture feeds, a study was conducted to evaluate the suitability of a protein isolate from coastal Bermuda grass Cynodon dactylon for channel catfish Ictalurus punctatus. The coastal Bermuda grass was treated by soaking in liquid anhydrous ammonia under high pressure at 70 C, a process known as Ammonia Fiber Explosion (AFEX), followed by pressure release, extraction and isoelectric precipitation for isolation of the protein. Amino acid analysis of the isolate (32% crude protein) indicated a generally balanced profile that was first limiting in methionine. A feeding trial was conducted in which four isonitrogenous and isocaloric diets containing incremental levels of the extracted, isolated protein were evaluated. The control diet contained 10% menhaden fishmeal and experimental diets were formulated so that the isolate replaced 33, 66 and 100% of the fishmeal on an equal‐protein basis. Each diet was fed for 9 wk to triplicate groups of channel catfish fingerlings initially weighing approximately 14 g/fish. Apparent protein and organic matter digestibility of the isolate also was determined utilizing chromic oxide as an inert marker. Results of the feeding trial indicated that substitution of the isolate at all levels did not significantly (P > 0.05) affect weight gain, feed efficiency, protein efficiency ratio or protein retention of channel catfish. Apparent protein and organic matter digestibility coeflicients of the isolate were 85 and 89%, respectively. These data indicate that the isolate was readily digested by channel catfish and was able to replace menhaden fishmeal (at 10% of diet) without adversely affecting fish performance. Additional research to evaluate substitution of other ingredients with the protein isolate appear warranted. Further research to optimize protein isolation procedures also is required.
Comparative Net Absorption of Chelated and Inorganic Trace Minerals in Channel Catfish Ictalurus punctatus Diets
Authors: Paripatananont Tippawan , Lovell Richard T.
Published: April 2007

Coefficients of net absorption for copper, iron, manganese, selenium, and zinc were determined for chelated sources (copper proteinate, iron proteinate, manganese proteinate, selenium proteinate, zinc proteinate) and inorganic sources (copper sulfate pentahydrate, ferrous sulfate heptahydrate, manganese sulfate monohydrate, sodium selenite, zinc sulfate hep‐tahydrate) of these elements with channel catfish Ictalurus punctatus. Fish weighing approximately 60 g were placed into 40‐L aquaria (12 fish/aquarium) at a temperature of 28 f 2 C and fed either an egg white‐based, purified diet or a soybean meal‐based, practical diet with and without the test mineral sources for 6 wk then killed and feces collected from the hindgut. Treatments were arranged in a 2 × 2 factorial design. Absorption coefficients for the elements in the basal and mineral supplemented diets were calculated by the indirect indicator (chromic oxide) method and corrected for residual amounts of element in the basal diets. Net absorption of the chelated minerals was significantly higher (p < 0.05) than net absorption of the inorganic minerals in both basal diets. Average percentage improvement in net absorption of chelated minerals over inorganic minerals was 39.3% in the purified diets and 81.1% in the practical diets. These results may indicate that appreciably lower amounts of chelated trace minerals than inorganic trace minerals can be used as supplements in catfish feeds.
Preliminary Results on the Fatty Acid Composition of Freshwater Crayfish, Astacus astacus and Pacifastacus leniusculus, Held in Captivity
Authors: Ackefors Hans , Castell John , ÖRde‐Öström InCa‐Lena
Published: April 2007

The fatty acid compositions of the tail muscle and hepatopancreas of captive noble crayfish Astacus astactus and of signal crayfish pacfastacus leniusculus were investigated. The major fatty acids in the tail muscle of A. astacus were 16:0. 18:ln‐7 + 9, 20:4n–6 and 20:5n–3 and the fatty acid composition of hepatopancreas was principally 16:0, 18:In‐7 + 9 and 20: ln‐9+ 11. These animals had been fed marine fish (sprat and herring) for 2 mo. They were kept in a flowthrough system with gravity‐fed fresh water from a nearby lake with a high concentration of calcium and pH above 8. The major fatty acids in the tail muscle of P. leniusculus were 16:0. 18:ln‐7+9, 18:2n–6 and 20:5n–3, and in the hepatopancreas 16:0, 18:1n–7 + 9 and 18:2n–6. These animals had been fed mainly plant material (green peas, maize and alder leaves) in a different laboratory for a period of about 2 yr and kept in a flow‐through system with ambient water of pH around 7. In A. astacus the total fatty acid content was nearly 13 times higher in the hepatopancreas than in the tail muscle, however, three fatty acids 18:0, 20:4n–6 and 20:Sn‐3 were, respectively, 289, 403, and 320% more concentrated in the fatty acids of tail muscle than in the hepatopancreas. Total fatty acids of the hepatopancreas of male P. Ieniusculus was 42 times higher than in the tail muscle and was three times greater than in the hepatopancreas of A. astacus.
Induced Breeding of Two Clariid Catfishes Clurius gariepinus and Heterobranchus bidorsalis Using Tilapia Pituitary Extracts
Authors: Salami Adekunle A. , Bello‐Olusoji Oluayo A. , Fagbenro Oyedapo A. , Akegbejo‐Samsons Yeml
Published: April 2007

Induced breeding trials of two clariid catfishes, Clarias gariepinus and Heterobranchus bidorsalis, were conducted using five doses (2, 4, 6, 8 or 10 mg/kg) of acetone‐dried tilapia pituitary (ADTP) extracts. Oocyte maturation and ovulation were induced in female catfishes by single intramuscular injection of 6–10 mgkg ADTP; optimum results were obtained with 8 mgkg in both catfishes. At ambient temperature (27 ± 1 C). ovulation occurred within 14–18 h post‐injection resulting in 16–20% increase in egg diameter. Fertilization and hatching percentages increased (P < 0.05) with increases in hormone dosage. Survival of fry fed a mixed zooplankton diet was high (ranging from 79% to 85%) after 30 d of rearing.
Relationships Among Total Weight, Body Shape, Visceral Components, and Fillet Traits in Palmetto Bass (Striped Bass Female Morone saxatilis× White Bass Male M. chrysops) and Paradise Bass (Striped Bass Female M. saxatilis× Yellow Bass Male M. mississippiensis)
Authors: Bosworth Brian G. , Libey George S. , Notter David R.
Published: April 2007

Relationships among total weight (W), and linear measures of body shape, visceral component weights, and fillet weight (Y) in market‐size (>454 g) palmetto bass (Morone saxatilis female ×M. chrysops male, N= 138) and paradise bass (M. saxatilis female ×M. mississippiensis male, N= 134) were determined with the allometric equation: Y = aWb. Allometric analysis was used to compare traits of palmetto bass and paradise bass, and to identify factors influencing fillet yield. Paradise bass, an all female hybrid, had deeper, thicker, shorter bodies, and smaller heads than palmetto bass females. Male and female palmetto bass had similar body shapes. Values of growth coefficients (b) for body shape traits (range 0.21–0.48) indicated that shape was proportional across the weight range of fish used. Mean visceral fat and ovary weight were higher in paradise bass than in palmetto bass females suggesting the reproductive cycle was more advanced in paradise bass females. Whole fillet (skin and ribs intact) and skinless fillet (ribs intact) were larger for paradise bass than for palmetto bass, but trimmed fillet (skin and ribs removed) was not different between fish. Relative increases of whole and skinless fillet weights were greater than total weight in both groups indicating that the percentage of body mass attributed to fillet increases slightly as total weight increases. Therefore, small increases in fillet yield can be achieved by rearing fish to a larger size. Stepwise regression of whole, skinless, and trimmed fillet weight on body shape traits resulted in three parameter models with r2‐values of 0.27–0.29 in palmetto bass, and of 0.37–0.43 in paradise bass. Addition of visceral components as independent variables in the models increased r2‐values to 0.31–0.36 for palmetto bass and to 0.45–0.52 for paradise bass. Low phenotypic variation in fillet yield (CV = 3–5%) and poor predictability of yield from measures taken on live fish limit the potential for improving yield through individual selection. Identification of superior species or strain crosses or rearing fish to a larger size appear to be the best strategies for improving fillet yield of Morone hybrids.
Effect of Stocking Density on Growth and Water Quality for Largemouth Bass Micropterus salmoides Growout in Ponds
Authors: Tidwell James H. , Webster Carl D. , Coyle Shawn D. , Schulmeister Greg
Published: April 2007

Juvenile largemouth bass Micropterus salmoides, trained to accept artificial diets, were stocked into six 0.04‐ha ponds at stocking densities of either 6,175 or 12,350 fish/ha. Fish were fed a floating custom‐formulated diet, containing 44% protein, once daily to satiation for 12 mo (May 1994–May 1995). At final harvest, the total yield of fish was significantly greater (P < 0.05) and feed conversion ratio (FCR) was significantly lower, for bass stocked at the higher density (4,598 kg/ha and 2.3, respectively) than when stocked at the lower density (2,354 kg/ha and 3.3, respectively). There was no significant difference (P > 0.05) in average weight, length, or survival of bass stocked at the two densities. Averaged over the study period, there were no significant differences (P > 0.05) in total ammonia‐nitrogen (TAN), nitrite‐nitrogen, or un‐ionized ammonia concentrations in ponds in which bass were stocked at the two densities. These data indicate that largemouth bass of the size used in this study are amenable to pond culture at densities of at least 12,350 fish/ha and that higher stocking densities may be possible.
Ingestion Rate and Feeding Behavior of the Peppermint Shrimp Lysmata wurdemanni on Artemia Nauplii
Authors: Zhang Dong , Lin Junda , Creswell R. LeRoy
Published: April 2007

A laboratory study was conducted to examine the effects of food level and water temperature on the ingestion rate in the larvae of the peppermint shrimp Lysmata wurdemanni, a popular aquarium species. Artemia nauplii were used as the food item. Number of newly hatched Artemia nauplii consumed by the larvae (from zoea II to zoea VII, zoea I can metamorphose to zoea II without exogenous nutrition in about one day) was measured daily at four food concentrations (2, 5, 10 and 20 Artemia nauplii/mL) and two temperature levels (25 C and 28 C). The experiment was conducted in 500‐mL beakers with three replicates for each treatment. The results show that the shrimp consumed significantly more food at 28 C than at 25 C (P < 0.01). Ingestion rate increased with increasing food concentration in all larval stages and with larval development except for the lowest food level (2 Artemia nauplii/mL) where insufficient food supply limited the ingestion rate to around 35 Artemia nauplii/ larva per d after zoea IV stage. The larval development rate was significantly lower (P < 0.05) in the shrimp subjected to the two lowest food concentrations (2 and 5 Artemia nauplii/mL) in the 500‐mL beakers. But in a separate experiment conducted in the 1,400‐mL beakers, the results were reversed: both survivorship and development rate were significantly lower at the two higher food levels (6 and 12 nauplii/mL) than those at 3 nauplii/mL level. During molting period, ingestion rate decreased significantly, followed by a sharp rise to the normal rate the following day.
All‐male Tilapia Hybrids of Two Strains of Oreochromis niloticus
Authors: Marengoni Nilton G. , Onoue Yoshio , Oyama Tetsuo
Published: April 2007

Hybridization between Nile tilapia Oreochromis niloticus (Local and Stirling University strains) and blue tilapia O. aureus was found to be a tool to produce monosex populations. In order to select a purebred that produces all‐ or nearly all‐male hybrids with high productivity, O. niloticus females and their diploid gynogenetics (meiogynes and mitogynes) were hybridized with O. aureus males. The sex ratio of progenies was evaluated from inter‐ and intraspecific crosses of two strains of Nile tilapia. Single‐pair matings and group spawns under hatchery conditions showed no deviation (P > 0.01) from the expected sex ratio of intraspecific crosses among two strains of Nile tilapia. However, a higher proportion of male progenies in blue tilapia was observed in group spawns in pond (P < 0.004) and hatchery conditions (P < 0.01). Only the Stirling strain and mitogynes produced all‐male progenies under laboratory conditions. There were significant differences (P < 0.05) in growth among hybrid progeny groups, when gynogens and their regular O. niloticus (Local strain) females were crossed with O. aureus males. Six‐month hybrid offspring from mitogyne female parents grew better than those from regular and meiogyne female broods.
Comparison of Practical Diets with and without Animal Protein at Various Concentrations of Dietary Protein on Performance of Channel Catfish Ictalurus punctatus Raised in Earthen Ponds1
Authors: Robinson Edwin H. , Li Meng H.
Published: April 2007

Abstract— A 2 × 5 factorial experiment was conducted using practical‐type extruded feeds containing 20, 24, 28, 32, or 36% crude protein with or without animal protein. The animal protein supplement consisted of 4% menhaden fish meal and 4% meat, bone and blood meal. Channel catfish fingerlings (average size: 26.3 g/fish) were stocked into 50 0.04‐ha ponds at a rate of 24,700 fishha. Five ponds were used for each dietary treatment. Fish were fed once daily to satiation for 202 d. There were no differences in feed conversion ratio (FCR), percentage fillet moisture, and survival among treatments. In fish fed diets containing no animal protein, feed consumption, weight gain, and percentage dressout were lower for fish fed the 20% protein diet than those fed diets containing 28% and 32% protein. Fish fed 28, 32, or 36% protein diets without animal protein did not differ in respect to percentage dressout and percentage visceral fat; fish fed the 36% protein diet had higher percentage fillet protein and a lower percentage fillet fat than fish fed other diets with the exception of fish fed the 28% protein diet. In fish fed diets containing animal protein, feed consumption, weight gain, percentage fillet protein and ash, and percentage dressout were lower and visceral fat was higher for fish fed the 20% protein diet than those fed other diets. Fish fed diets containing 24% protein and above with animal protein were not different in respect to weight gain and feed consumption, but fish fed the 24% protein diet had a higher percentage fillet fat than fish fed a 32% or 36% protein diet. Fish fed the 32% protein diet had a lower visceral fat. Considering animal protein vs non‐animal protein with the data pooled across all diets without regard to dietary protein level, weight gain and FCR of fish fed diets containing animal protein were higher than those fed diets containing no animal protein. However, weight gain of fish fed diets containing 20, 28, or 32% protein with or without animal protein did not differ. Dressout percentage and fillet protein were higher and fillet fat was lower for fish fed diets containing no animal protein than those fed diets containing animal protein. Data from this study indicated that animal protein may not be a necessary dietary ingredient for fish fed 28% or 32% protein diets typically used for grow out of pond‐raised channel catfish under satiation feeding conditions. Whether animal protein should be included in catfish diets containing less than 28% protein is unclear, since fish fed the 24% protein diet benefited from animal protein but those fed the 20% protein diet did not benefit from animal protein. Additional studies to provide more information on low‐protein, all‐plant diets are currently being conducted.
Effect of Reduction of Supplementary Dietary Vitamins on the Stress Response of Channel Catfish lctalurus punctutus
Authors: Davis Kenneth B. , Simco Bill A. , Li Meng , Robinson Edwin
Published: April 2007

Abstract— The influence of reduced amounts of supplemental vitamins on the stress response of channel catfish lctalurus punctatus was determined. Fish were fed diets with reduced levels of supplemental vitamin C, niacin, riboflavin, pantothenic acid, pyridoxine or thiamine, or with reduced amounts of the total vitamin supplement typically added to catfish feed. Fish were confined for 6 h and blood samples taken at 0, 1 and 6 h of confinement and 12 h after release. Plasma chloride and osmotic pressure were consistently stable throughout the experiment and were not influenced by the diet or the stress imposed. Cortisol concentrations were elevated at 1 and 6 h of confinement but recovered to preconfinement concentrations 12 h after release. The cortisol response varied in some of the groups; however, no consistent effects due to the vitamin concentrations were observed. The lack of supplemental vitamins in the food did not impair the ability of the fish to mount or maintain cortisol secretion. The feed ingredients may contain enough vitamins to support cortisol synthesis or the fish may be acquiring sufficient additional vitamins from the pond environment or from intestinal bacteria.
Effect of Water Temperature on Reproductive Tract Condition of Penaeus setiferus Adult Males
Authors: Pascual Cristina , Valera Evangelina , Re‐Regis Cristina , Gaxiola Gabriela , Sanchez Adolfo , Ramos Laida , Soto Luis A. , Rosas Carlos
Published: April 2007

Abstract— This study was conducted to determine the effect of water temperature on male reproductive tract degenerative syndrome (MRTDS) and male reproductive system melanization (MRSM) in Penaeus setiferus, and to evaluate the effect of water temperature on spermatophore regeneration time and sperm quality in electrically ejaculated adult males. Variation in sperm quality, gonadosomatic index, and histological changes in the reproductive system were used to assess reproductive tract changes in the first experiment. Sperm quality and regeneration time were measured before and after successive regenerations in the second experiment. Sperm quality was stable when shrimp were held at 26 C for 30 d but was reduced when shrimp were held at 30 C. Reproductive tissues of 20% of the shrimp held at 30 C were melanized to some degree but tissue melanization was found in only 2.5% of the shrimp held at 26 C. Spennatophore regeneration time was also affected by temperature. Average times for first spermatophore regeneration were 192 h at 25 C, 152 h at 30 C, and 144 h at 33 C. Sperm quality of regenerated shrimp was not affected at 25 C but was reduced for regenerated animals held at 33 C. Based on these results, we recommend a water temperature between 25 and 27 C to obtain adequate spermatophore regeneration and to maintain healthy male P. setiferus broodstock for at least 30 d.
The Effect of Dissolved Oxygen Level on the Weight Gain and Shell Hardness of New‐Shell American Lobster Homarus americanus
Authors: Bayer Robert , Riley John , Donahue Darrell
Published: April 2007

Abstract— New‐shell American lobsters Homarus americanus stored in tidal pounds or on‐shore tank systems are fed to promote weight gain and shell hardness prior to shipping. Maintaining adequate dissolved oxygen (DO) levels in the water is an important consideration in this process, and information on optimum DO levels is needed. In this study, 90 post‐molt lobsters were weighed and tagged and held in a recirculating seawater system. Three DO treatments, 50%. 100%. and 250% saturation, were applied in three replicates; the lobsters were held for 35 d and fed daily. After this period they were re‐weighed and shell hardness was measured. Results showed that increasing oxygen saturation above 100% did not increase weight gain or shell hardness and at lower levels (50%) there is only a trend to reduced shell hardness and weight gain.
Evaluation of Three Strains of Channel Catfish Ictalurus punctatus Fed Diets Containing Three Concentrations of Protein and Digestible Energy1
Authors: Li Meng H. , Robinson Edwin H. , Wolters William R.
Published: April 2007

Abstract A 3 × 3 factorial experiment was conducted using three strains of channel catfish Ictalurus punctatus, USDA102, USDA103, and Mississippi normal (MN), and three concentrations of dietary protein. Three practical diets were formulated to contain 25, 35, or 45% crude protein with digestible energy/protein ratio of 10.0, 8.1, or 6.8 Kcal/g, respectively. Juvenile channel catfish (mean initial weight: 15.1 g/fish) were fed the experimental diets twice daily to approximate satiation for 8 wk. Regardless of dietary protein concentration, the USDA 103 strain consumed more feed, gained more weight, and converted feed more efficiently than other two strains. The MN strain consumed less feed and gained less weight than the other strains. Regardless of the strain of channel catfish, differences in weight gain, feed consumption, and feed conversion ratio were observed among fish fed diets containing various levels of protein with the 35% protein diet being the best. Neither dietary protein concentration nor strain had significant effect on fillet protein level. Data pooled by fish strain showed that fish of MN strain had lower fillet fat and higher moisture than fish of other two strains. Data pooled by dietary protein showed that fish fed the 45% protein diet had a lower level of fillet fat than fish fed the 35% protein diet, but this did not appear to be a strain effect, rather it was a result of decreased feed consumption. Results from this study clearly demonstrate that per formance of the USDA103 strain of channel catfish was superior to other strains tested. The growth characteristics of the USDA103 strain of channel catfish make the strain a promising candidate for commercialization. However, data are needed on performance of the strain from fingerling to marketable size under conditions similar to those used for the commercial culture of channel catfish prior to their release to the catfish industry.
Impacts of Burrowing Ghost Shrimp, Genus Lepidophthalmus Crustacea: Decapoda: Thalassinidea, on Penaeid Shrimp Culture
Authors: Nates Sergio F. , Felder Darryl L.
Published: April 2007

Abstract The burrowing ghost shrimp Lepidophthalmus sinuensis Lemaitre and Rodrigues and Lepidophthalmus bocourd (A. Milne Edwards) have significant impacts on pond‐based culture of penaeid shrimp. Marked abbreviation of the larval cycle, an adaptation for estuarine retention in wild populations, favors accumulation of recruits into the same substrates as the parental population where densities of these burrowers sometimes exceed 650 individuals/m2. Higher densities of burrowing shrimp appear to correlate with lower yields of penaeid shrimp because of oxygen requirements by the thalassinids and also bioturbation effects. Rich sources of organic materials in highly reduced pond substrates can be readily exploited by Lepidophthalmus species due to their physiological adaptations to low oxygen concentrations. Bioturbation and ventilatory movement of water through burrowed sediments by ghost shrimp move reduced nutrients into the water column with potential toxic effects on penaeids. Ultimately, activities of these estuarine burrowers oxidize benthic sediments and cycle nutrients into the water column, the negative impacts of which are probably restricted to aquaculture settings.
Regression Analysis of Soil Chemical Composition for Two Shrimp Farms in Texas
Authors: Ritvo Gad , Speed F. Michael , Neill William H. , Dixon Joe B. , Lawrence Addison L. , Samocha Tzachi M.
Published: April 2007

Several nutrients, pH, organic matter, and total soluble salts of surface soil from 81 ponds on two Texas shrimp farms were measured. The relationship between shrimp yield and soil characteristics was analyzed statistically. Shrimp yield was negatively correlated with soil concentrations of S, P, NO3‐, B, Ca, Mg, K, Na, Cu, and total water‐soluble salts. Shrimp yield was directly correlated with soil concentrations of Fe, Mn, and organic matter. Stepwise multiple regression analysis indicated that Ca and S concentrations explained 54% of the variation in shrimp yield.
Replacement of Soybean Meal by Lupin Meal in Practical Diets for Juvenile Penaeus monodon
Authors: Sudaryono Agung , And Elena Tsvetnenko , Evans Louis H.
Published: April 2007

The potential of lupin meal as an alternative protein source to soybean meal in isonitrogenous practical diets for the juvenile black tiger shrimp Penaeus monodon was evaluated through the studies of growth, digestibility and pellet water stability. Five isonitrogenous diets were formulated to contain 40% protein. Protein from dehulled Lupinus albus seed meal replaced 0, 25, 50, 75 and 100% of the protein from defatted soybean in the diets. Juvenile P. monodon (4.35 × 0.31 g) were assigned randomly and fed each test diet at a daily feeding rate of 5 % body weight for 42 d in triplicate tanks equipped with a flow‐through sea water system. No statistically significant differences were observed in weight gain, feed intake, feed conversion ratio (FCR), protein conversion efficiency and apparent protein utilization of shrimp fed diets with 0, 25, and 50% replacement. Shrimp fed the diet with total replacement of soybean meal by lupin meal had the poorest performance (P < 0.05) with regard to the above parameters. Survival was similar (87%) for all dietary treatments. The apparent dry matter digestibility and apparent protein digestibility were similar for all diets ranging between 70.5 and 72.8% and 89.7 and 90.8%, respectively. There was no significant difference in whole body composition (dry matter, lipid, protein and ash) of shrimp on the various diets. The poorest pellet water stability was displayed by the diet with 100% replacement while the diet containing a combination of soybean meal and lupin meal (50% replacement) was the most stable. The results have demonstrated that dehulled lupin seed L. albus meal has good potential as a substitute protein source for up to 50% of the protein from defatted soybean meal and could be included up to 17% inclusion level in juvenile P. monodon practical diets with no adverse effects on growth, feed intake, FCR, survival, feed utilization, body composition, and digestibility coefficients of dry matter and protein.
Effects of Seasonal Variations, Thyroid and Steroid Hormones, and Carp Pituitary Extract on the Artificial Production of Channel Catfish Ictalurus punctatus× Blue Catfish I. furcatus Hybrids
Authors: Lambert Dayton M. , Argue Brad J. , Liu Zhanjiang , Dunham Rex A.
Published: April 2007

The primary objective was to compare thyroid hormones and levels of carp pituitary extract for the artificial production of female Ictalurus punctatus× male I. furcatus hybrid catfish. The effects of different carp pituitary extract dosage rates (5, 6, 9, and 10 mg/kg), carp pituitary extract (6 and 10 mg/kg) supplemented with the thyroid hormones thyroxine (T4) and triiodothyronine (T3), or pregnenolone (DHP) were determined for inducing ovulation of female channel catfish, fertilization of channel catfish eggs with male blue catfish sperm, and hatching rate of these embryos. Hormone treatments thyroxine and tri‐iodothyronine with carp pituitary extract, carp pituitary extract alone, and pregnenolone with carp pituitary extract used to artificially produce hybrid catfish were not different in terms of ovulation rates, eggs/kg, fry/kg body weight of female channel catfish, fertilization rates, or hatching rates (P > 0.05). These findings suggest that lower amounts of carp pituitary extract may be used to induce spawn of female channel catfish for production of channel‐blue catfish hybrids and the addition of thyroid and steroid hormones is ineffective at the rates used in this study.
Dietary Vitamin C Requirement of Hybrid Striped Bass Morone chrysops♀× M. saxatilis ♂
Authors: Sealey Wendy M. , Gatlin Delbert M.
Published: April 2007

A feeding trial was conducted to determine the dietary vitamin C requirement of juvenile hybrid striped bass Morone chrysops × M. saxatilis. Fish were fed a semi‐purified basal diet with 40% crude protein and an energy to protein ratio of 8 kcal/g for a conditioning period of 2 wk. This diet which was not supplemented with vitamin C contained approximately 6‐mg vitamin C/kg. Following conditioning, fish (approximately 0.55 g initial weight) were stocked as groups of 20 in 38‐L aquaria and fed the basal diet and experimental diets supplemented with 10, 20, 30, 45, 60, 75, or 150‐mg vitamin C/kg as ascorbate polyphosphate for a period of 10 wk. Fish fed the basal diet and the diet supplemented with 10‐mg vitamin C/kg exhibited signs of vitamin C deficiency including suppressed weight gain, reduced plasma and liver ascorbic acid levels, and abnormalities in isthmus cartilage formation. Plasma and liver ascorbic acid levels generally reflected dietary supplementation with the lowest levels occurring in fish fed the basal diet and higher levels in fish fed the supplemented diets. The minimum dietary requirement (±SE) based on non‐linear least squares regression analysis of weight gain was 22 (±6) mg vitamin C/kg diet.
Effect of Dietary Protein Concentration and Feeding Rate on Weight Gain, Feed Efficiency, and Body Composition of Pond‐Raised Channel Catfish Ictalurus punctatus1
Authors: Robinson Edwin H. , Li Meng H.
Published: April 2007

Two experiments were conducted in earthen ponds to evaluate the effect of dietary protein concentration and feeding rate on weight gain, feed efficiency, and body composition of channel catfish. In Experiment 1, two dietary protein concentrations (28% or 32%) and four feeding rates (≤ 90. ≤ 112, ≤ 135 kg/ha per d, or satiation) were used in a factorial arrangement. Channel catfish Ictalurus punctatus fingerlings (average size: 27 g/fish) were stocked into 0.04‐ha ponds at a rate of 24,700 fish/ha. Fish were fed once daily at the predetermined maximum feeding rates for 282 d (two growing seasons). In Experiment 2, three dietary protein concentrations (24, 28, or 32%) and two feeding rates (≤ 135 kg/ha per d or satiation) were used. Channel catfish (average size: 373 g/fish) were stocked into 0.04‐ha ponds at a rate of 17,300 fish/ha. Fish were fed once daily for 155 d. In both experiments, five ponds were used for each dietary treatment. Results from Experiment 1 showed no differences in total feed fed, feed consumption per fish, weight gain, feed conversion ratio (FCR), or survival between fish fed diets containing 28% and 32% protein diets. As maximum feeding rate increased, total feed fed, feed consumption per fish, and weight gain increased. There were no differences in total feed fed, feed consumption per fish, or weight gain between fish fed at ≤ 135 kg/ha per d and those fed to satiation. Fish fed the 28% protein diet had a lower percentage carcass dressout and higher percentage visceral fat than fish fed the 32% protein diet. Dietary protein concentrations of 28% or 32% had no effect on fillet protein, fat, moisture, and ash. Feeding rate did not affect FCR, survival, percentage carcass dressout, or fillet composition, except fillet fat. As feeding rate increased, percentage visceral fat increased. Fish fed at ≤ 90 kg/ha per d had a lower percentage fillet fat than fish fed at higher feeding rates. In Experiment 2, dietary protein concentration or maximum feeding rate did not affect total feed fed, feed consumption per fish, weight gain, FCR, or survival of channel catfish. Feeding rate had no effect on percentage carcass dressout and visceral fat, or fillet composition. This was due to the similar feed consumption by the fish fed at the two feeding rates. Fish fed the 24% protein diet had lower carcass dressout, higher visceral fat and fillet fat than those fed the 28% or 32% protein diet. Results from the present study indicate that both 28% and 32% protein diets provide satisfactory fish production, dressed yield, and body composition characteristics for pond‐raised channel catfish fed a maximum rate of 90 kg/ha per d or ahove.
Effect of Culture Temperature on Growth, Survival, and Biochemical Composition of Yellow Perch Perca fiavescens
Authors: Tidwell James H. , Coyle Shawn D. , Evans Jeff , Weibel Charles , McKinney Jonathan , Dodson Kim , Jones Halimah
Published: April 2007

Juvenile yellow perch Perca fiavescens were evaluated under controlled conditions in tanks for 13 wk to determine the effect of temperature on growth to advanced sizes under intensive culture conditions. Yellow perch weighing 6.6 ± 1.5 g were stocked into nine 4,755‐L tanks at 131 fish/m3 (625 perch/tank). There were three replicate tanks per temperature (20, 24, and 28 C). Perch were fed to apparent satiation twice daily using a 45% crude protein diet with 16% crude fat. After 93 d the perch in the 24 C treatment were significantly larger (P < 0.05) than those in the 20 C and 28 C treatments, which were not significantly different (P < 0.05) from each other. Yellow perch raised at 28 C had significantly higher (P < 0.05) feed conversion ratios and significantly lower (P < 0.05) survival and net protein utilization than perch raised at 20 C or 24 C. Whole body moisture was significantly higher in (P < 0.05) yellow perch raised at 20 C which also had significantly higher levels of arachidonic acid (20:4 n‐6) and docosohexaenoic acid (22:6 n‐3). The ratio of palmitic acid (16:0) and palmitoleic acid (16:1 n‐6) had a positive correlation (P < 0.05) with culture temperature. These data indicate that 24 C may be an optimum temperature for yellow perch. At 20 C survival and feed conversion are good but growth rates are reduced. Temperatures near 28 C appear sufficient to represent chronic stress conditions.
Partial Replacement of Fish Meal with Corn Gluten Meal in Diets for Japanese Flounder Paralichthys olivaceus
Authors: Kikuchi Kotaro
Published: April 2007

Abstract.— Feeding experiments were conducted to evaluate corn gluten meal (CGM) as an alternative protein source for fish meal in the diet of Japanese flounder Paralichthys olivaceus. A diet containing 75% white fish meal as a sole protein source was the control, and 20, 40, and 60% of fish meal protein was replaced with CGM protein in the experimental feeds. Juvenile fish of about 8 g initial body weight were fed each diet to apparent satiation twice a day. 6 d per week for 8 wk at 20 C. Survival rates of fish ranged from 98 to 100% and were not significantly different (P > 0.05) among treatments. Final body weight, weight gain, feed efficiency and protein efficiency ratio of fish fed the diets containing CGM up to 40% substitution levels were not statistically different from those of fish fed the control diet. All production parameters for fish fed the diet replacing 60% of fish meal protein were significantly lower than the control (P≤ 0.05). Supplements of crystalline amino acids to the CGM diet improved the nutritive value of the diet. Since substitution up to 40% did not adversely affect hematological and hematochemical parameters as well as whole body composition of the cultured fish, it is suggested that up to 40% of fish meal protein can be replaced with CGM in the diet of juvenile Japanese flounder.
Effects and Interactions of Stocking Density and Added Substrate on Production and Population Structure of Freshwater Prawns Macrobrachiurn rosenbergii
Authors: Tidwell James H. , Coyle Shawn , Webel Charles , Evans Jeff
Published: April 2007

The effects and interactions of added artificial substrate with different stocking densities of prawns were evaluated. Juvenile prawns (0.2 ± 0.1 g) were stocked into 12 0.04‐ha ponds at 60,000ha and 120,000/ha with and without substrate. Added substrate consisted of horizontal plastic mesh and strips of “oyster netting” sutlicient to increase available surface area 80%. There were no statistically significant (P > 0.05) interactions between stocking density and presence of added substrate, allowing these main effects to be compared separately. Increasing stocking density produced a significant increase (P < 0.01) in total production but a significant decrease (P < 0.01) in average prawn size and production (P < 0.05) of market size prawns (>20 g, ‐27%; > 30 g, ‐56%). Added substrate also produced a significant increase (P < 0.05) in total production (18%). However, average prawn size was not decreased and production of marketable shrimp was increased (>20 g, 25%; >30 g, 19%). Feed conversion ratios were significantly decreased (P < 0.01) by the presence of substrate. Increased stocking density significantly increased (P < 0.05) the percentage of males which were small males (SM) and decreased (P < 0.01) the percentage of orange claw males (OC), but had no impact (P > 0.05) on numbers of reproductive (RF) and virgin (VF) female morphotypes. Increased stocking density also produced a significant decrease (P < 0.05) in average size of OC, RF, and VF morphotypes while the addition of substrate had no statistically significant impact (P > 0.05) on the number or size of different morphotypes. The mathematical relationship between available surface area and average prawn size should be determined to produce recommended inclusion rates for added substrate based on desired levels of total production, stocking rates, and optimum market sizes.
Histopathological Studies on Wild Broodstock of White Shrimp Penaeus vannamei in the Platanitos Area, Adjacent to San Blas, Nayarit, Mexico
Authors: Morales‐Covarrubias Maria Soledad , Chavez‐Sanchez Cristina
Published: April 2007

In Mexico, the capture of wild broodstock of Penaeus vannamei or P. stylirostris for hatchery production of postlarvae is a common practice. During September 1995 and March‐April 1996, high mortalities were observed in the wild broodstock captured in the Platanitos area, on the coast of San Blas, Nayarit, Mexico. As a result of these mortalities, many hatcheries closed down their facilities. Because early histological analysis had shown that some of these animals were infected with different pathological agents, such as bacteria and viruses, the present study was carried out to determine the prevalence and severity grade of infectious diseases affecting these shrimp. During March 1996, a total of 28 female and 28 male shrimp were randomly selected from a recently captured stock of 600 breeders of P. vannamei. A second sampling (28 females and 28 males) was performed from a stock of 800 breeders captured in April 1996. On this occasion, the shrimp were sampled after 10 d of acclimation in a hatchery. The animals selected for examination were those with necrosis in the cuticule, red coloration in the telson and uropods, soft cuticle, empty gut, and erratic swimming. All of the specimens were subjected to histological analysis and dot blot hybridization with a gene probe specific for Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV). The results showed that both stocks were infected with at least three different viruses (Infectious Hypodermal and Hematopoitetic Virus, Taura Syndrome Virus and Hepatopancreatic Parvo‐Like Virus), gram‐negative bacteria and other parasites such as gregarines. It is likely that the high mortalities observed are due to the recent introduction of TSV in the wild population of P. vannamei.
The Effect of Astaxanthin in Feed and Environmental Temperature on Carotenoid Concentration in the Gonads of the Green Sea Urchin Strongylocentrotus droebachiensis Müller
Authors: Hávardsson Björgólfur , Imsland Albert K. , Christiansen Rune
Published: April 2007

The aim of this study was to investigate the long term development of carotenoid concentration in gonads and gonad development of green sea urchins reared at different temperatures and fed formulated feed containing dwerent levels of astaxanthin. Urchins, sampled from a natural population, were reared under two different temperature regimes (7 C and 12 C) and fed formulated feed containing 0, 100 and 500 mg astaxanthin/kg feed, respectively. The study lasted 112 d. Astaxanthin was detected in the groups fed feed containing astaxanthm, but in low quantities. No effect of temperature was observed on the retention of astaxanthin. Echinenone values declined throughout the study, probably due to the lack of suitable metabolic precursor for production of echinenone. Water and lipid concentration in the gonads increased throughout the study indicating the progressions of gametogenesis and the generally improved nutritional status of the animals. No significant difference in gonad index (GI) due to treatment was observed but GI varied between the sexes with male GI increasing significantly faster compared to females.