bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproduction of Eyestalk‐AblatedPenaeus stylirostrisFed Various Levels of Total Dietary Lipid
Authors: Bray William A. , Lawrence Addison L. , Lester L. James 
Published: April 2007

AbstractEffects of total dietary lipid (TDL) on reproduction ofPenaeus srylirostriswere compared using a series of diets ranging from 7.8% to 13.9% TDL. In addition, a commercial feed was compared to the experimental feeds, and a single fresh diet component (squid as 40% of diet) was compared to a multiple fresh component portion (squid, bloodworms, shrimp, and brine shrimp as 40% of diet). The control diet consisted of the four fresh components in equal proportions.Significant differences among diet treatments during 87 days of evaluation were observed for mean percent hatch, number of nauplii per spawn, and percent females mating per night. A new parameter, protozoea I length, was evaluated also and appeared to be a sensitive measure of treatment differences. In general, the all‐fresh component diet (control) and diets with multiple fresh components performed better than those with a squid‐only component. Among the three diets varying only in total lipid content, the middle level (11.1% TDL) treatment means were significantly higher (P< 0.05) than the highest lipid treatment (13.9% TDL) based on number of nauplii per spawn, percent females mating per night, and protozoea length. The middle level treatment means were also higher than the low lipid level tested (7.8% TDL) for these parameters, but only protozwa length was significantly higher (P< 0.01).In the best treatment (100% Fresh), there were 189,000 ± 10,300 eggs per spawn (mean ± SE), 103,000 ± 10,400 nauplii per spawn, 51.3 ± 4.3 percent hatch (N =64), and 7.0 ± 0.7 percent females mating per night (N= 174). The High Lipid treatment, in which the poorest results were obtained, produced 164,000 ± 11,100 eggs per spawn, 39,000 ± 9,400 nauplii per spawn, 23.0 ± 4.8 percent hatch (N =40) and 3.9 ± 0.5 percent females mating per night (N= 174). Results indicate that dietary lipid levels affect reproduction and that 10% to 11% total lipid produced better results than 7.8% and 13.9%.
Acceptance and Consumption of Food by Striped Bass and Hybrid Larvae
Authors: Tuncer Haluk , Harrell Reginal M. , Houde Edward D. 
Published: April 2007

AbstractFood acceptance, consumption and weaning times were investigated for striped bass (Morone saxatilis) and hybrid striped bass (M. saxatilis×M. chrysops) larvae. Experimental treatments consisted of: control groups of striped bass (SC) and hybrids (HC) fed Artemia nauplii; hybrids fed formula food (HF); and hybrids weaned from Artemia nauplii to formula food at 11–15 days (HF1), and 18–22 days (HF2) posthatch. The formula diet did not support growth and resulted in total mortality of the HF hybrids by the third week posthatch. HF1 fish had significantly slower growth and lower survival than HF2 of HC. The HF2, HC and SC groups had similar growth and survival, which indicated no heterosis in hybrids. There were no differences in Artemia nauplii consumption by the SC and HC groups. Daily consumption increased exponentially for both groups (0.8 to 50–60 cal/day/larva between 7 and 30 days posthatch). Weight specific consumption (WSC) decreased initially and then increased for both groups. A mean WSC of 58% (range of 24–83%) was found for the combined SC and HC groups. Food conversion ratio, growth efficiency, caloric efficiency, and productive protein values were similar for striped bass and hybrid larvae.
Changes in Plasma Concentrations of Sex Steroids in Adult Pacific Halibut, Hippoglossus stenolepis
Authors: Wu Liu Han , Stickney Robert R. , Dickhoff Walton W. 
Published: April 2007

AbstractBlood samples were collected from captive Pacific halibut, Hippoglossus stenolepis, at intervals of about six weeks from early December 1986 to late November 1987. Concentrations of plasma androgen and estradiol‐17β were determined by radioimmunoassay. The plasma concentrations of steroid were highest during autumn and winter in halibut that matured during late winter. The concentrations of steroids in samples collected in December were above 2 ng/mL (estradiol) or 1 ng/mL (androgen) in maturing females and below 0.5 ng/mL for both steroids in non‐maturing females. The levels of steroids decreased rapidly about one month before spawning. In a mature male, androgen began to rise in August and November, and reached a peak of 7 ng/mL in early December. One month before spawning, the androgen concentration fell to 0.16 ng/mL. Estradiol concentrations were detectable in the male and varied little during the year. In immature fish, neither androgen nor estradiol changed significantly throughout the year. These results suggest that the concentrations of estradiol or androgen measured in blood samples taken during December may be used to determine the sex and state of maturation of Pacific halibut.
Nitrogen Budget for the Rotifer Brachionus plicatilis
Authors: Tanaka Yoshiaiu 
Published: April 2007

AbstractNitrogen ingested by the rotifer, Brachionus plicatilis (S type) is balanced by gain in body nitrogen (including reproduction), soluble excreted nitrogen, and nitrogen as egested feces. Every term in the budget was estimated independently, and measured as directly as possible. A comparison of the observed and calculated nitrogen as egested feces yielded a satisfactory result.The nitrogen ingested by the rotifer was distributed as follows: 15.6% for growth and reproduction, 42.0% for metabolic excretion, and 42.4% as feces. From these results, it was concluded that a large proportion (84%) of the nitrogen ingested by the rotifer is transferred to water in various forms and may cause deterioration of the water quality.
Artificial Spawning of Tilapia Eggs1
Authors: Myers James M. , Hershberger William K. 
Published: April 2007

AbstractA stripspawning methodology was evaluated for tilapia (oreochromid) species. This technique achieved an average hatching success of 68.6 ± 3.6% (N= 31). Female fecundity and spawning frequency were dependant on both genetical and husbandry factors. Egg yields for Oreochromis niloticus, O. mossambicus, and O. niloticus±O. mossambicus hybrids averaged 4.54, 10.86 and 10.36 eggs/g female/spawn, respectively. Female broodstock that were adapted to an intensive spawning regime exhibited a significant increase in fecundity. Additionally, egg survival was not affected by hydration for up to 15 minutes prior to fertilization. Results suggest that the strip spawning of tilapia species may be an efficient method of providing viable gametes for hatchery purposes.
Toxicity of Un‐ionized Ammonia and High pH to Post‐larval and Juvenile Freshwater Shrimp Macrobrachium rosenbergii
Authors: Straus David L. , Randall Robinette H. , Heinen John M. 
Published: April 2007

AbstractPost‐larval and juvenile Macrobrachium rosenbergii were exposed for 72 h at 29 C to four pH levels (8.5, 9.0, 9.5, 10.0) and four concentrations of un‐ionized ammonia‐nitrogen (0, 1, 2, and 3 mg/L NHj‐N). Results indicated potentiation between NH3 and high pH. Juveniles were more tolerant of high pH and NH3 than post‐larvae.For post‐larvae, estimates of 72 h LC50 for pH were 9.43, 9.21, and 8.71 at 0, 1, and 2 mg/L NH3‐N, respectively; 72 h LC50 estimates for NH3‐N were 2.18 and 1.45 mg/L at pH levels of 8.5 and 9.0, respectively. For juveniles, estimates of 72 h LC50 for pH were 9.91, 9.56, 9.04, and 8.76 at 0, 1, 2, and 3 mg/L NH3‐N, respectively; 72 h LC50 estimates for NH3‐N were 2.02 and 0.54 mg/L at pH 9.0 and 9.5, respectively.In pond culture of M. rosenbergii, high pH levels can cause mortality at stocking. The 72 h data can be used as an indication of safe stocking levels of pH and ammonia. These data suggest that post‐larvae should not be exposed to pH > 9.0 nor to NH3‐N > 1 mg/L in the pH range 8.5–9.0 and juveniles should not be exposed to pH > 9.5 nor to NH3‐N > 0 mg/L at pH 9.5, > 1 mg/L at pH 9.0, or > 2 mg/L at pH 8.5.
Reproductive Performance of Pigmented and Albino Female Channel Catfish Induced to Spawn with HCG or Ovaprim
Authors: Goudie Cheryl A. , Simco Bill A. , Davis Kenneth B. , Parker Nick C. 
Published: April 2007

AbstractReproductive performance of albino and pigmented channel catfish (Ictalurus punctarus) females was compared when spawning was induced with HCG (human chorionic gonadotropin) or Ovaprim3 (domperidone and [d‐Ala6, Pro9 NEt]‐luteinizing hormone‐releasing hormone). In 1985, only HCG was used to induce spawning. Albino females required more injections, had a longer latency period from time of first injection to spawning, and had lower spawning success (30%) than pigmented females (77%). No differences were observed between albino and pigmented females for time‐of‐day of spawning, number of eggs obtained by manual stripping, and number of eggs/kg body weight. In 1988, HCG, Ovaprim, and saline (control) were used to induce spawning. HCG induced spawning in 80% of albino and 71% of pigmented females. Ovaprim induced 67% of pigmented females to spawn, but only 2 of 5 albino females spawned. One of four pigmented females injected with saline spawned. Albino females yielded 40–50% fewer eggs/kg body weight than pigmented females. Other performance characteristics for albino and pigmented females were similar whether injected with HCG or Ovaprim. High temperatures encountered during the 1985 spawning season my have had a differential effect on albino and pigmented fish and may account for some differences in spawning success.
Impact of Double‐Crested Cormorant Depredations on Channel Catfish Farms
Authors: Stickley Allen R. , Warrick Gordon L. , Glahn James F. 
Published: April 2007

AbstractResurgent wintering populations of double‐crested cormorants in the past 10 years have caused serious depredation problems for commercial channel catfish (Ictalurus punctarus) growers in Mississippi. Catch rates of catfish by cormorants were found to average 5 catfish per cormorant‐hour. Catfish taken averaged 12 cm in length. However, cormorants took fingerling catfish at rates as high as 28 per cormorant‐hour. The average number of cormorants found feeding on a single pond in this study was 30.5. If this number (but not necessarily the same individuals) fed all day in an 8 ha pond stocked at 51,000 fishlha, the fish population would be halved in 30 days. Further, using this example, the cost of harassment patrols on a 200 ha catfish farm complex over a 5 month period would be exceeded in 22 days by the losses in this one pond. Wild gizzard shad (Dorosoma cepedianum) occurred in some ponds, and seem to be preferred by cormorants over caffish.
Recent Advances in Lumpfish Cyclopterus lumpus and Ocean Pout Macrozoarces americanus Larviculture
Authors: Brown Joseph A. , Somerton Donna C. , Methven David A. , Watkins John R. 
Published: April 2007

AbstractThe aquaculture of marine finfish in Newfoundland presents a challenge due to the cold‐water (<0 C) conditions which occur over a four to five month period. As part of a continuing research program on the culturing of cold‐water marine finfish species we report on preliminary results of two “new” aquaculture species. The lumpfish and the Ocean pout both occur along the coast of Newfoundland and are adapted to a cold‐water environment. Lumpfish have been reared from egg masses collected from the wild or from eggs stripped in the hatchery. Eggs and larvae are relatively large and larvae are well developed at hatch. Larvae will feed on day‐old Artemia nauplii after four to six days. Survival over the first eight weeks is high but declines over the first year. Lumpfish cultured in the laboratory become sexually mature and produce eggs (roe) at the end of their second year. Ocean pout have been cultured only from egg masses collected from the wild. Eggs and larvae are extremely large compared to other marine finfish currently being cultured. Larvae hatch during the cold‐water period, absorb the yolk‐sac within 24 hours and are ossified at hatch. Juveniles feed on Artemia nauplii within two days at very low temperatures. Survival is comparatively high (75–80%) over the first year. Initial results are encouraging but more research is required before commercial production of these species would be feasible.
Marine Fish Larvae Feeding: Formulated Diets or Live Prey?
Authors: People Le Ruyet Jeannine , Alexandre Jean Claude , Thébaud Laurence , Mugnier Chantal 
Published: April 2007

AbstractIn the rearing of larval marine fish, any diet that reduces dependance on live prey production is of technical and economic interest. Weaning juveniles with a completely developed digestive tract to a conventional diet, (i.e., “late weaning”) can be successful in any marine fish species. For example, weaning one‐month‐old sea bass (20 mg) to the study's reference diet, Sevbar, resulted in over 85% survival (40% from hatching) and 1.25 g fish at day 90 (at 19 C)In contrast, “early weaning” of larvae to special microdiets during the first month is still difficult. The best way to reduce live prey utilization in sea bass is to wean larvae at about 3–4 mg in size (day 20). If weaning could be accomplished 15 days earlier, Artemia savings could be as high as 80%. However, this introduces risks relative to growth retardation (30% weight loss) and lower juvenile quality, including greater size variability and skeletal abnormalities. Similar results have been obtained with commercial microparticles (Fry Feed Kyowa) and experimental microbound diets (MBD) made from raw materials (alginate MBD) or preferably from freeze‐dried protein sources (zein MBD).Total replacement of live prey is still impossible in marine fish. Sea bass larvae fed formulated diets exclusively from first feeding (0.3 mg larval wet weight), or even from their second week of life onwards, exhibited low survival and poor growth. Better results can be obtained when formulated diets are used in combination with live prey from first feeding, although the optimal ratio of live prey to formulated diet is still to be specified.
A Review of Cannibalism and its Implications in Fish Larviculture
Authors: Hecht Thomas , Pienaar Anthony G. 
Published: April 2007

AbstractA review of cannibalism is presented with particular emphasis on the role that this phenomenon plays in applied larviculture. Cannibalism is more ubiquitous than previously assumed and its implications under larviculture conditions are significant. The review is focused primarily on the two principal causes of sibling cannibalism. These are genetic and behavioral, the latter being influenced directly by environmental factors. Cannibalism is regarded as an alternative feeding strategy, more likely to be adopted by larvae and early juveniles which are carnivorous, when resources become limiting. Agonistic behavior induced mortality, the causes of which are identical to those of cannibalism, is also dealt with. Experimental results on the effects of several important environmental factors are presented and evaluated, and suggestions are made to reduce mortality rates under larviculture conditions.
Preliminary Comparisons of the Native Penaeus setiferus and Pacific P. vannamei White Shrimp for Pond Culture in South Carolina, USA
Authors: Sandifer Paul A. , Hopkins J. Stephen , Stokes Alvin D. , Browdy Craig L. 
Published: April 2007

AbstractTwo pond experiments were conducted at the Waddell Mariculture Center to compare production characteristics of the native Penaeus setiferus and Pacific P. vannamei white shrimp in South Carolina. In 1985, 7–9 day old postlarval P. setiferus were stocked in one 0.1 and one 0.25 ha ponds, while P. vannamei of the same age were stocked in one 0.1 and one 0.25 ha ponds, while P. vannamei of the same age were stocked in one 0.1, one 0.25, and one 0.5 ha ponds. Both species were stocked at 12 shrimp/m2. The shrimp were fed a 25% protein commercial food and harvested by draining after 147 d. Sarvival in all ponds was > go%, but growth and production of the P. setiferus were considerably lower than values obtained for P. vannamei: 12.8 g and 1,555 kg/ha/crop for P. satiferus versus 19.7 g and 2,477 kg/ha/crop for P. vannamei. In 1989, duplicate 0.1 ha ponds were stocked with P. setiferus and P. vannamei at 60 shrimp/m2, and two additional 0.1 ha ponds were stocked with P. setiferus at 40/m2. The P. setiferus postlarvae were produced at the Waddell Center from captive‐reared and wild South Carolina brood stock. Rearing procedures involved paddlewheel aeration (10 hp/ha), regular water exchange (averaging 16–21%/d in all ponds), and use of a 40% protein feed. Due to the availability of postlarvae, the various treatments were stocked at different times. Both P. setiferus treatments were reared for 145 d, while the P. vannamei were reared for 165 d. P. setiferus at the 40/m2 density attained mean size, survival, and standing crop biomass at harvest of 13.5 g, 97.5% and 5,259 kg/ha/crop, respectively. The 60/m2P. setiferus treatment was stocked 2 wk earlier and yielded 15.2 g mean weight, 87.5% survival, and 7,995 kg/ha/crop at harvest. The P. vannamei 60/m2 treatment, which was stocked 3 wk earlier than any of the P. setiferus, produced mean size, survival and standing crop biomass at harvest of 17.1 g, 69.5% and 7,187 kg/ha/crop. Both survival and production levels would have been higher had not one replicate experienced a partial mortality due to a feeding accident. The 1989 study yielded what is thought to be the highest production levels yet achieved with P. setiferus in pond culture. These results suggest that P. setiferus may be a viable alternative to P. vannamei for intensive cultivation in the continental U.S. when P. vannamei are unavailable. Further evaluation of this potential is needed.
The Effects of Water Exchange on Production of Metapenaeus macleayi and Water Quality in Experimental Pools
Authors: Allan Geoff L. , Maguire Greg B. 
Published: April 2007

AbstractTwo experiments in 4 m diameter, plastic lined pools were conducted nt two densities, 20 shrimp/ m2 and 47 shrimp/m2, to determine the effects of water exchange rate on the production of the penaeid shrimp Metapenaeus macleayi (Haswell) and on water quality variables. Water exchange rates ranged from 0–40%/d for the 9 wk low density experiment and 0–20%/d for the 8 wk high density experiment. With the exception of mass mortality after prawns escaped from one pool (0% water exchange) on the last day of the high density experiment, shrimp performance indices (survival, weight gain, biomass gain and food conversion ratio) were not significantly affected by water exchange rate. During both experiments water exchange significantly reduced the concentrations of phosphorus and plant pigments (chlorophyll a, b and c and pheophytin) but had no significant effect on pH or the concentration of ammonia or nitrite plus nitrate. Data from this study suggest that while production ponds should not be managed for extended periods without water exchange, simply increasing daily water exchange rates may not necessarily increase shrimp growth or survival. Water exchange can reduce nutrient concentrations and phytoplankton densities but most of the reduction occurs at water exchange rates of between 0–5%/d.
The Cost of Production of Giant Clam Seed Tridacna gigas
Authors: Tisdell Clement A. , Thomas William R. , Tacconi Luca , Lucas John S. 
Published: April 2007

AbstractThe costs of providing giant clam seed in Australia are examined for alternative annual volumes of production. Considerable economies of scale in production are available, both in relation to labor costs and non‐labor costs (mostly capital costs). The fall in per‐unit cost of producing giant clam seed is considerable when annual production is expanded from 100,000 to 500,000 seed clams per year. At 10% rate of interest, the unit cost per clam seed falls from $1.43–$2.04 at a production level of 100,000 to $0.41–$0.55 at a production level of 500,000. Per‐unit operating costs also fall. They decline from $1.01–$1.22 to $0.29–$0.35. This suggests that there are likely to be cost economies in having large centralized hatcheries.
Combined Effects of Diet and Salinity on European Sea Bass Larvae Dicentrarchus labrax
Authors: Barnabé Gilbert , Guissi Abderrafie 
Published: April 2007

AbstractEffects of diet, salinity, and consumption of endogenous reserves on the growth, survival and swim bladder inflation of European sea‐bass larvae were studied. Primary inflation of the swim bladder occurs in 7‐day‐old larvae. Inflation is synchronized with the absorption of endogenous reserves. The kinetics of the consumption of these reserves varies with the diets tested, and is the slowest at higher salinity (28.7 and 37.7‰). Best results were obtained with larvae fed on Artemia nauplii. Larvae raised at lower salinity (19.7 and 10.7‰) had the highest proportion of inflated swim bladders. Larvae raised at 28.7‰ salinity had the best survival rate, while those raised at 38.7‰ had the best growth rate. Larval mortality was associated with inappropriate functioning of the swim bladder. Larvae exposed to decreasing salinity during rearing showed very high survival rates and normal swim bladder inflation.
Riboflavin Requirement of Fingerling Red Hybrid Tilapia Grown in Seawater
Authors: Lim Chhorn , Leamaster Brad , Brock James A. 
Published: April 2007

AbstractRed hybrid tilapia Oreochromis mossambicus×O. niloticus fingerlings were fed diets containing 0, 2.5, 5.0, 10.0, 20.0 and 40.0 mg/kg, and 0, 2.5, 5.0, 7.5, 10.0 and 20.0 mg/kg of riboflavin in separate 8 and 12 wk feeding studies, respectively. The dietary riboflavin level required to provide maximum growth and survival, and prevent deficiency symptoms in red hybrid tilapia fingerlings was found to be approximately 5 mg/kg of diet. In both trials, fish fed the diet devoid of supplemental riboflavin exhibited anorexia, reduced growth and nervous symptoms after 4–6 wk. Mortality began to occur after the sixth week. None of these abnormalities were observed during the first 6 wk in fish fed the riboflavin supplemented diets. However, by the seventh week, fish fed the diet supplemented with 2.5 mg/kg of riboflavin showed reduced appetite and growth rate. In both experiments, short body dwarfism was observed during week 8 for fish fed the diet without riboflavin supplementation. In experiment 1, fish fed the riboflavin‐deficient diet had lens cataracts at week 8. This deficiency sign was not observed in experiment 2. Histological studies of liver, kidney, spleen, lateral muscle, gill and gastrointestinal tract revealed no major histopathological changes.
Early Larval Growth of Pacific Halibut Hippoglossus stenolepis
Authors: Liu Han Wu , Stickney Robert R. , Dickhoff Walton W. , McCaughran Donald A. 
Published: April 2007

AbstractGrowth of Pacific halibut Hippoglossus stenolepis larvae was studied in the laboratory during 1989 and 1991. Larvae increased in length from 6.3 mm at hatching to 9.9 mm 20 d post‐hatch. The average daily length increment was 0.17 mm. Dry weight of the larvae increased from an average of 210 μg at hatching to 570 μ g on day 20, providing a specific growth rate of 4.99. During the same period, mean yolk sac weight decreased from 1,390 μ g to 646 μ g, resulting in a yolk to body conversion efficiency of 48.5%. At hatching, the larval body made up only 13% of total dry weight. On day 20, the larval body made up 46.9% of the total weight. Larvae started feeding at a length of 12 mm after about 90% of their yolk sac had been absorbed.